We eat, sleep, and go to the bathroom. Yet, we never think about how all these physical needs are processed in the systems of our body when they are functioning normally.

Yes, our bodies are created with perfect systems by which our all kinds of needs are met. The digestive system is one of them. Our intestines are key elements of this system, so much so that asking someone “How are your intestines?” would be as comprehensive as asking “How are you?”

Digestive system

Food is critical to life. A human being can bear hunger for one month at most and can only endure a few days of drought. Thus, eating and drinking is crucial.

Foods as we eat them are not convenient for use by the cells. Food must be broken down into smaller pieces. This process begins in the mouth and ends at the anus, and it is called digestion.

The main task of our stomach and intestines is digestion. The teeth, salivary glands, the tongue, and the gullet – as well as swallowing – are essential secondary elements. Additionally, if the pancreas or liver fall ill, it can paralyze the whole system. While also working with the circulatory system, kidneys have the task of reabsorbing useful substances like glucose, amino acids, and water.

Our digestive system works together with the urinary system and the digestive organs like a factory. How these parts work together is still not fully understood, but more detailed research has been performed and revealed more secrets of the digestive system. By means of every discovery, it is realized that this perfect creation has a more intricate structure than is known.

The brain in the intestine

There are more neurons in our intestines than in our spinal cord and the intestines are created in a way that can move independently from the central nervous system. They have their own nervous system, known as enteric nervous system (ENS), which is also called the “second brain. “Within those yards of tubing lies a complex web of microcircuitry driven by more neurotransmitters and neuromodulators than can be found anywhere else in the peripheral nervous system. These allow the ENS to perform many of its tasks in the absence of central nervous system (CNS) control…” [1]. Thus, “… isolated segments of intestine can independently coordinate propulsive movements and propel content without any neural connections to the brain or spinal cord [2].

The intestines take action when food comes into the stomach. This movement is known as colonic migrating motor complexes (CMMC), and it moves the substances that cannot be digested, like bone and fiber. According to neurophysiologist Nick Spencer et al, “The gut wall contains a complete network of intrinsic nerves capable of propelling contents along the bowel, without any requirement of nerves originating in the brain or spinal cord” [3].

Eat different types of food

70% of our immune system cells are in our intestines. A big part of the approximately 38 trillion bacteria in our body are in our intestines, and they are useful; they have a big role in digesting food. Different groups of bacteria feed on different types of food; so for intestinal flora it is very important to have a variety of food on our table. For the ideal day on a plate Dr. Megan Rossi recommends people should “aim for at least 30 different plant species per week.” “The reason for this is that each plant contains different types of fibres and phytochemicals (the super healthy components of plants) that feed different good bacteria. The more plant variety, the more variety of gut bacteria – which is associated with health and happiness” [4].

Pets in our body

For Dr. Megan Rossi, “microbes are like our pets, so you have to take care of them and feed them” [5].

Of course, germ flora in our body is not just limited to the ones in the intestines. Bacteria, viruses, and fungi in our body are nearly scattered throughout the whole body. These living things produce pellicle on our head skin, irritate the gaps between our toes, live on our skin, are on duty among our teeth, and have ecosystems and assigned positions convenient to them. According to the situation, they keep their living spaces healthy or unhealthy. Although they number 50 trillion, they are approximately 200 grams of our body weight.  

Useful microbes

An average size human adult houses about 10¹² bacteria on the skin, 10¹⁰ in the mouth, and 10¹⁴ in the gastrointestinal tract [6].

These microorganisms are useful microbes with duties in our body. The harmless flora of microbes is generally present on the skin, mouth, teeth, nose, throat, and bowel and genital areas. There isn’t normal flora in internal organs except the large bowel. Internal organs have no microbes. If we look closely, flora is inserted in every part of our body which is dirty and has contact with the outer environment. If it was not for the useful flora, microorganisms causing illness would settle instead. Only intestinal bacteria are permanent microbes which are useful. For example, vitamin K plays a part in a crucial event like blood clotting and is produced in the intestine.

Control your stress

Research has revealed that mental and psychological stress affects the health of the intestines. Serotonin is produced automatically in case of need, and 85% of it is produced in the digestive tract. Stress suppresses the level of serotonin produced. Psychological illnesses are associated with low levels of serotonin.

Studies have shown that relaxing practices like meditation for 15-20 minutes can be good for health and reduce stress. At this point, daily prayers are a kind of therapy. Other ways to stay healthy include: avoiding things like alcohol and caffeine, and sleeping well.

Our body has ways of telling us when it’s not healthy. For instance, we can learn the digestive tract isn’t healthy if we have to use the toilet more than three times a day and fewer than three times a week.

References

1. Gershon, Michael D. “The Enteric Nervous System: A Second Brain.” Pdfs.semanticscholar.org.
2. Spencer et al. 2018. “Identification of a Rhythmic Firing Pattern in the Enteric Nervous System That Generates Rhythmic Electrical Activity in Smooth Muscle.” http://www.jneurosci.org/content/38/24/5507
3. http://www.flinders.edu.au/neuroscience/lab_visceral.html
4. https://www.dailymail.co.uk/femail/article-5543159/Doctor-debunks-myths-surrounding-gut-health-say-surprise-you.html
5. https://navva.org/brazil/health/why-the-bowel-is-considered-our-39-2nd-brain-39-and-other-5-amazing-facts-about-the-organ-news/
6. http://www.textbookofbacteriology.net/normalflora_3.html

(continued from the previous issue)

Using the distinct groves and folds on the hemispheres as a guideline, a map drawn on the cortex identifies focal points, where the various senses are concentrated, and activities in particular regions. Each of these different colored schematic centers has a specific name and performs specific functions. For example, the region above the neck at the back of the head (occipital lobe) is the field of sight; the sections that coincide with the temporal region is the field of hearing; immediately in front of this, on the left, is (generally) the field of speech; in the forehead region (frontal lobe), on the anterior wall of the middle canal is the initial center of planning of movement; on the top section of the front region is the field of complex movement; immediately behind here, in the middle-side region, is the field of simple movement; the area behind this, next to the hearing field and extending upwards, is defined as the touch receptive field. However, these areas are not confined, but rather spread out, and have a very complex connection network. The duty of the adjoining areas of these regions is to display and decipher the meaning of the signals received from the nerves. As the received signals regenerate past experiences and memories, the object or event sending the signal is recognized. To perform voluntary complex movements, the plan of movement must initially be defined in the mind and then the combination of this plan is conveyed through my nerve fibers to the movement regions. As complicated activities in humans, such as talking, and activities that involve the sensory integration mechanisms are miracles in themselves, it is quite astonishing that certain people claim that humans evolved from apes, later learning how to speak. The spinal cord (medulla spinalis) that extends from the skull in the form of a long cord, is the central nervous system sending signals to the body regions under the neck. The grey matter of the brain is located on the surface, while the white matter lies beneath the cortex; however with the spine, the butterfly shaped grey matter is inside, and the white matter on the surface covers the grey matter. In this central nervous system, all of the sensual messages that are received from the entire peripheral system, in particular from your skin and muscle, are immediately connected with the synapses or connections of the movement cells, and thus a spinal reflex is produced. As a section of the connecting cells (synapses) responds with a reflex, the other section transmits the signal to me to determine the appropriate voluntary response. For instance, if you tread on a nail, as the nail goes into the foot, a signal is transmitted by the sensor fibers to the spine, and to avoid a loss of time, the spine immediately signals the movement nerves before me, and a command is transmitted to your muscle you to raise your foot. And after your foot is saved by instant reflex, you begin to perform the other conscious activities, for example; you avoid putting weight on the foot, and bandage the wound if it is bleeding.

31 pairs of nerves (right and left) emerge from the spinal cord; 12 pairs from the brain area lay beneath the skull. These are all nerves that emerge from the central nervous system, and are distributed to various organs of the peripheral nervous system. All of the head nerves that emerge from the skull, with the exception of the tenth nerve, called the vagus nerve, control activities related to movement and senses in the head and neck region. Each of the 31 nerves exit from a space in the side of the vertebrae, and each of these nerves has two roots, an afferent nerve (sensual nerve), and an efferent nerve (movement nerve). These roots join immediately outside the spinal cord, and form the cords that carry the sensual and movement nerve fibers. These nerve cords are distributed in a plan and system that is specific for each organ. For example, the receptor sensor cells that sense a needle pricking your finger transmits this signal to the spinal cord through the receptor cell of the arm. The responsive reflex of pulling the hand away, a reflex from the spinal cord, is sent to the arm and hand muscles, and you pull your hand away. This is an example of a simple reflex. The movement nerve cells of the peripheral nervous system are divided into two, the somatic nervous system, which is distributed to the skeletal muscles, and the autonomic nervous system, which is distributed to the inner organs. Whilst the majority of the activities of the somatic systems occur voluntarily at the conscious level, the activity of autonomic systems is mainly involuntarily, or below the level of consciousness. The autonomic nervous system controls the smooth muscles of the heart, glands, blood vessels, respiration, digestion, urination and reproduction systems without our even realizing it. Dear Peter! Could you manage to do all this if you were in control? Your self control can only intervene until you place food in your mouth. Then the digestive secretions, the stomach and bowel activity, and the excretion of waste are all conducted automatically, totally beyond your control. Your breathing continues while you sleep, your kidneys never cease to function, your heart never rests, and your liver never relaxes while you sleep; your pancreas continues to produce insulin. All of your internal organs and blood vessels continue to function with the smooth muscles whenever necessary. And all this activity is conducted without you even being aware of it. If you tried to do all this, you would become exhausted within five minutes, lose interest and become unable to cope.

The nerve cords of the autonomic nervous system are divided into two, the sympathetic and the parasympathetic. These two systems have been created in such a way that they respond in opposition to one another, and every organ is provided with a stem from both. Therefore, no organ of the body is left uncontrolled. Whilst one signals and encourages the organ to function quicker and generate more outcomes, the other acts to the contrary, sending signals that encourage the organ to slow down. In which case, with these two contrasting signals, the organ protects its optimal functioning tempo according to the situation and conditions. The sympathetic system generally responds in cases of stress and shock, preparing the body for the effects of such situations. For example, an increase in your blood pressure, blood-sugar level, and perspiration, the dilation of your pupils, and an increase in the flow of blood in your muscles all occur from the effect of the sympathetic fibers. The parasympathetic system sends adverse signals, such as reducing blood pressure and so on, so that the organs return to their neutral state and continue their normal functions.

From the very beginning I have described many of my sections and signals, but I have not yet told you about my key to life, my nerve cells, and how my nerve cells function. 30 billion cells, known as neurons, are the actual units that function in every part of my system. A neuron has a cell body and emerging filaments like tree branches. The single thicker filament like the tree trunk is called the axon, and the thinner filaments that emerge in larger quantities like tree branches are called dentrites. The nerve signals advance from the axon to the dentrite in the form of an electrical pulse. In the space between the connection point (synapses) of a nerve cell axon and the other cells, the dentrite, a chemical substance, called the neurotransmitter, is released. When these substances, in the form of neuropeptides, amino acids, acetylcholines, and monomines, reach the wall of the opposite cells, it an electrical pulse is immediately ignited in the dendrite. Just like a row dominos, falling down one after the other, or football fans performing the Mexican wave, a wave-like effect is generated and these electrical messages are fired with great speed from one end of the cell to the other, advancing in the form of tiny electrical pulses to be transmitted to neighboring cells. While a cell at rest has a potential of 70m V, the action potential of up to +30 – +40m V can transmit all types of information. Every cell can transmit up to 1,000 signals per second.

While you still do not recognize the true value of what you call the memory, which records hundreds of experiences every day, various theories are presented regarding how this bank which stores information in your brain actually functions. But we all know that the answer to this question lies within the millions of neurons that constitute me. Just as all of the senses, thoughts and actions occur from electrical and chemical signals that are transmitted from one cell to another they are presumably recorded in the same way, that is, with electrical and chemical signals.

It is difficult to define a precise center for the boundaries of the memories in me; memory could be interconnected with all of my regions. The storing of certain memories, some voices, visions, smells, or dreams, or the sense of resentment, anger or joy, is all carried out in different forms. You could not even begin to imagine the greatness of the memory storage! I have two types of memory, one short and one-long term. In my short term memory, I can store up to between seven and nine different things at any one time. Nothing remains in my short-term memory for more than a few minutes. Everything that you remember after this is stored in my long-term memory. In my long-term memory things can remain for days, months or even years. Everything you know and learn is stored in your long-term memory. By the time you are eight years old, the information in your memory is enough to fill one million pages. However, this is a mere drop in the ocean; the long-term memory is so vast that it can never become full. Even when you reach a hundred, I will have the capacity to store new information, so never assume that you are overloading a child’s mind and never deprive them of education…Some presumptuous people say; “Never force a child to memorize at a young age, it will affect the brain.” Do not believe them! The learning of foreign languages, the Qur’an and religious education is recorded in my memory by electric pulses and this is so much easier and healthier in the early stages of life. In fact, such activities at a young age can even strengthen the memory. The event called ‘recollection’ is the repeat of the electric pulse codes that are recorded at the actual time of an event. Occasionally you try to remember a person’s name, and although the name is on the tip of your tongue, you just cannot remember. You struggle and eventually give up. Then suddenly, two days later the name comes to your mind. You are quite puzzled and of course pleased that you have remembered, but have you ever wondered how this happens? As you try to remember, you control each of my nerve cells individually, because you are not sure where you placed the files that bear this information. But you are unable to find which section of the millions of cells bears the information. As you have not used this information often, or because you did not consider it to be important, you did not register it in a particular place. But you would never forget your father’s name, as it is important to you and use it often, so the file is in front of you constantly. Well, you get frustrated at not being able to remember and stop searching; however, what you call the subconscious is in fact a much more mysterious mechanism. It begins to search without you being aware of it. Then to your surprise it produces the file two days later. The subconscious is a very mysterious place, it affects everything about you. Only the most sincere feelings are recorded in the subconscious; no veil, no hypocrisy, only actual thoughts are recorded. And also events that deeply affect you, the sad or bad memories you experience, and of course sins…The subconscious is what causes the sense of guilt or an inferiority complex; this is reflected in much of your behavior. But problems like guilt or an inferiority complex are something we can change; it all depends on you. If you are a person who has self-control, you perform good, favorable deeds, and are continuously patient; thus you can eventually renew the contaminated sections of your subconscious so that it will not upset you anymore. Indeed, this is the reason why, of all the creatures on earth, only humans were blessed with the sense of remorse and faith. If you suppress feelings of guilt and sin in the subconscious, the autonomic system affects the organs without you even realizing it; the thalamus, hypothalamus, or the pituitary gland (hypophsis), which are small in size, but bear a great responsibility; eventually this disturbs the balance of the whole body and you become ill. Although this may not be an organic complaint at first, due to psychosomatic symptoms which are caused by suppressing your subconscious, over time this will affect the functions of one of your organs and you become ill. Of course the exact opposite is also possible, with inspiration, pleasant thoughts and good actions the positive signals transmitted to the affected organ may possibly be the means to recovery.

Dear Peter! I have so many more facts and mysterious functions to describe to you, but unfortunately the pages here are not enough. Well, I suppose I must stop somewhere. I really wanted to talk to you about a number of different things, like dreams, mental illnesses such as Parkinson’s, Alzheimer’s, strokes, sleep, hypnosis, and the damage caused by drugs. However, each of these subjects is so vast, and many of them have already been explained in previous issues, so for now I will leave it to others to describe these subjects to you, and say my last words…

Dear Peter!… While your hand is writing and reading these words, or explaining what you have read to your friends, or learning all this information and passing it through the filter of thought, you are constantly using my nerves and my systems. There is not a single moment where I am not informed of events that occur in your body. Who knows just how much of the mysteries in me you will use in order to rise to the peak of accomplishment with the blessings that have been bestowed upon you by the Creator. Even the greatest computers made by human beings are mere toys compared to me. Nevertheless, the knowledge of engineers and craftsmen which design, plan, and place every piece into these computers with total accuracy is only possible because of me. Presumably you are not denying those who designed, constructed, and made the computer operate, are you? In which case you should thank God, the One who created me, an organ whose capacity exceeds that of thousands of computers, with His eternal power and wisdom; always remember to use me in good, blessed, and honest actions!…May God protect you!…

Irfan Yilmaz is a professor of biology at Dokuz Eylul University, Izmir. 

Finally, I have come to say goodbye to you. As you probably know, there is a saying “Leave the best till last.” I am the greatest of all the organs and systems that have described themselves to you so far. I am an integrative system that forms a chain between every organ in your body. Just as your veins are spread out to carry nutrients and oxygen to every part of your body, I also embrace your entire system like a network, without leaving the tiniest space; I am informed of everything that goes on inside your body. Even if a tiny insect settles on your arm, you sense it immediately. I make you aware of a tiny drop of sweat on your body. I induce pain in suitable measures to inform you of any illnesses in your inner organs. In fact, I not only inform you, I also warn you to seek help.

However, it is hard for me to describe myself. When you hear the words “nervous system,” what comes to mind is a cluster of cells called neurons. But this is a great mass of cells, and we should always remember that we are referring to the most complex matter in all of creation. The very important main nervous systems, which are very close to one another, are the huge masses positioned beneath the skull, the extensions of my system and secondary nervous system; this latter is spread out through various regions of the body. It would take up too much of your time to describe each region and branch of my system individually to you each month, but in this way I could prove what a perfect and incredible duty each of them performs within your body. However, I will try to explain the subject briefly to avoid boring you. Nevertheless, please forgive me if I ramble on too much; we are describing the most excellent organ created by God so it is inevitable that there will be some complicated matters that need clarification.

Instead of allowing each of my sections to describe themselves to you individually, I will speak on their behalf as the “brain.” It may be easier for you to understand the system if we divide it into two. One of them is me and the nervous system which I lead; we can briefly describe this as the thalamus, hypothalamus, cerebellum, the medulla, and the spine. The other part is the peripheral nervous system, which emerges from the central nervous system and is distributed, rather like fiber optic telephone cables, throughout the entire body. In addition to me, the brain, and my two large cerebral hemispheres, there is another smaller section, which is known as the brain stem. The brain and its cerebral hemispheres and the sections of the brain stem which are protected beneath the skull (the cerebellum, medulla, thalamus, and hypothalamus) are very important. The spinal cord, which is also a part of the central nervous system, however is not in the skull, but positioned within the vertebrae that constitute the spine. Due to its connection with the central nervous system, any damage to the spinal cord can endanger life.

Although damage to regions of the body where the nerves are distributed from the central nervous system may cause paralysis, or functional disorder for the specific organ, such an incident is not life threatening.

If you recall, when the heart and circulation system described themselves they boasted – indeed the veins also seemed to brag a bit when they stated that they measured 75,000 miles (long enough to go around the world almost three times). But the nerves are approximately 477,000 miles, long enough to stretch from the earth to the moon, and back again… the nerves which are distributed throughout the various parts of your body measure 250,000 miles, and the total length of the central nervous system is 228,000 miles. Almost 200,000 signals pass through just one cell at a time, which means that every moment thousands of signals pass through millions of my cells all throughout your body, and flow from the central nervous system to the whole body and then back to the central nervous system. There are about 30 billion cells in my system. 10 billion of these cells are in the cortex, 10 billion in the cerebellum, and the remainder forms the structure of the nerves and other sections. As a comparison, a fly’s brain contains 100 thousand cells, and a rat’s brain has 10 million cells. The total number of connections and contact points (synapses) that my 30 billion cells use to send and receive signals is 100 trillion. The number of combinations that these connections can establish to send signals to one another is greater than the number of atoms in the universe. At the beginning of a thinking process, the number of cells activated is between 10 and 100 million, and according to the depth and intensity of the activity, these figures can increase to astounding numbers. Every second 4 billion signals are exchanged between the left and right hemispheres. When you were an embryo, just a few weeks old, I consisted of 92% water. When you were first born, the ratio of water was 90%. And when you were fully developed, the water ratio remains at 77%. Peter! Can you imagine, a heap of mass consisting of 77% water, the remainder made up of various element. Our Lord, the bearer of eternal power places me in you, in the head of the most honorable creation, and with me you form civilizations; you invent and discover. And even more important, with my mediation you have the ability to contemplate and reach your Creator. What we are learning about here is how with me you are able to recognize the wisdom of the entire universe. The electric signals of the various sense organs, such as the eyes, ears, nose, tongue and skin, all of which have previously described themselves, are transmitted by the receptive cells on various wavelengths; these are then conveyed to you in the form of sight, noise, smell and taste. In fact I am inducing you to write these words at this very moment. The evaluation of everything you do passes through me, but you are not even aware of it. When you walk, eat, talk, speak or sleep, the information I receive from every part of your body is reviewed and responded to in a suitable manner. Dear Peter! Could a single nucleus of a single one of my cells possibly position itself alone?

The Lord has created me so magnificently that you are still only aware of a very few of my mysteries. Each of the sections that I mentioned above has a distinct and important vital function. On their behalf, I will briefly explain their duties: The cerebellum is the nerve center from which the harmony of balance and muscle movement is controlled. As this section of me has no sense of perception, it is impossible to voluntarily change the functions of this region. The pyramid shaped medulla oblongata, which connects the spinal cord to the midbrain and the pons; the latter constitutes the other end of the brainstem through a hole in the back of the skull in the form of the spinal cord and enters into the vertebral column. Here, there are many nerve centers which regulate autonomic nervous system activity, such as the heart rate, breathing, and digestion process. This is also the center from which the reflexes are controlled, the body’s inner environment is regulated, and this center, working with the cerebellum also controls movement and coordinates signals received from the nerves of inner organs. Moreover, activities such as excitement and sleep are also controlled here in collaboration with the thalamus.

The thalamus lies between the brainstem and the hemispheres of the brain, performing a function rather like a junction or relay station. This section gathers all the signals sent by the sense receptors, except for those from the olfactory (smell) receptors, and conveys these signals to the cortex reflecting the information; there is also a role played in consciously identifying sensations such as pain, touch and noise. There is also a role played in the sensory changes that occur with the perception of senses in our consciousness and awareness, as well as in the regulation of sleep and paying attention. The hypothalamus, which is located below the thalamus, is an important center that controls sexual senses; the sensations of pain, pleasure, hunger, and thirst, as well as blood pressure, temperature and other functions of the inner organs. It also performs the important duty of regulating hormone release. The nerve fibers that enter this center, which is the location of a very complex network of nerves coming from the olfactory bulb, thalamus, and the frontal lobe, reach the autonomic nervous system, the reticular formation in the stem section, and the posterior lobe behind the pituitary gland (hypophysis). The pituitary gland, one of the most important systems that earlier described itself in the endocrine system, produces hormones that stimulate secretion in the anterior section, as well as the oxytocin and antidiuretic hormones which are stored and released from the posterior pituitary.

On the base of the deep grove that separates the two hemispheres of the large brain there is a callus-like body; this is a bundle of axon (nerves) called the corpus callosum which connects the two hemispheres. Because the nerve fibers cross and change direction in the medulla, the left side of the brain controls your right side, and the right controls your left. Although my two hemispheres may look like a reflection of one another, there are some variations in their duties; for example, the left hemisphere controls speech, but the section which controls the perception of location is in the right hemisphere. Whilst you use the left hemisphere for duties that must be performed in a specific order (activities such as adding and subtracting or buttoning a shirt), you use the right hemisphere in thinking with images (for example, mapping the route from your home to the market). If the callus substance that connects my two hemispheres did not exist, there would be no communication between the two, therefore, you could read the word “fish,” but you would not be able to picture the image of a fish in your mind without the right hemisphere to achieve this.

The brain, the grey-colored mass of folds and grooves that covers the top of my anatomic hemispheres, the region where the main stems of my cells are found, is called the cortex or grey matter; the lighter colored matter that lies beneath this, the region where the axons (stems of neurons) are found, is called the white matter. My cortex region, which is composed of six layers of cells, is the center where the sensory signals are received and analyzed and where voluntary muscle movement is controlled, while also being the center of activities, such as learning, reasoning, and remembering. My two hemispheres, the focal point of conscious activity and thought that forms the large brain, constitute 85% of the whole brain. When you were first born I weighed 400 grams, but I grew very quickly, and by the time you were a year old I weighed 800 grams. When you were four years old, I weighed 1,200 gr. However, my growth began to slow down after the age of seven, and when you reach twenty, I will weigh approximately 1,379–1,434 grams. When you begin to pass your first youth, my weight begins to decrease every year by 1 gram, so when you reach seventy-five, I would have shrunk in comparison to when you were twenty. The reason for this decrease in weight is that approximate 50,000 neurons die, or cease to function daily, after you reach the age of twenty. The body cells of the cartilage, bone, skin, ligaments and the liver divide, regenerate and increase in number; however, the nerve cells that are part of me continue to increase until they reach the figure set out for you when you were formed in your mother’s womb; they then lose the ability to segregate. So if there is any damage, relative functions fail because the cells in that region have died. Then the question arises: As there is no increase in the numbers of cells, how does the weight continue to increase until the age of twenty? Well, there is not an increase in the numbers of cells; rather, there is an increase in the number and growth of connections between the cells and this is how my weight increases. Of course, nutrients are added to build and stimulate these connections. Subsequently, with age these connections begin to decrease. With ever experience you have, all the things that you learn or see during your youth these connections increase, and in turn this increases my capacity for thought and reasoning. If you continue to activate your brain by reading, writing and other social activities in old age, these connections continue to increase. Even if there is a decrease in my cells, you are able to continue your usual activities without losing any functions of the brain. But as soon as you say that is enough, it is time for a rest, my cells begin to withdraw their connections immediately, and in time you will certainly see the difference in my capacity. If the cells in my central nervous system are injured or damaged, they cannot repair themselves. However, if the cell bodies of my cells in the peripheral nervous system are not damaged the stems are repairable.

Thanks to this special feature if a severed arm, leg or finger can be carefully replaced with microsurgery, the nerves can repair themselves, and the limb will continue its normal functions. The visible cause of this characteristic is found in the nerves of the arms and legs, but not in the brain or spine, is the casing that surrounds this bundle of nerves that transmits signals for the cells to grow. Even with the greatest of techniques, no surgeon could sew the severed nerve fibers. However, thanks to the nerve casing that holds these fibers together (like the plastic that covers the electric cable, consisting of thin wires) the severed limb can be replanted. Then with guidance from this outer casing, each of the hundreds of fibers found inside grow 1 mm every day, and in a period of between 1 month and a year, they will begin to function again.

Irfan Yilmaz is a professor of biology at Dokuz Eylul University, Izmir. 

We invite you to embark on a journey with us to explore some fascinating perspectives that shed a light on our relationship with sound and music.

Dr. Jeffrey Thompson, the Founder and Director of the Center for Neuroacoustic Research in California (www.neuroacoustic.com), is recognized as a worldwide expert in the field of acoustic pacing frequencies that are incorporated into musical sound tracks. A consummate musician and composer in his own right, he has established a method for using modulated sound-pulses that change states of consciousness for optimal “Mind-Body” healing. Dr. Thompson believes that the sounds in nature resonate with us because they take us back to the beginning of our journey and our primary senses.

Matter&Beyond: Why are sound and music so central for us, both culturally and personally?

I don’t think I’ve found a single culture on earth which at some point hasn’t used sound as a prominent technique in healing, in religious rites, or as a means of attaining a change of consciousness in one way or another. I think the tradition probably dates back to the first use of sound as a soothing or healing means for mothers; that is lullabies for babies.

M&B: Is this our earliest experience with sound? Is this what you call primordial sounds?

If you go back to before the lullabies, we’re talking about womb experiences and it’s one of the primal things we all share; this is what I call primordial sounds. Certain type of sounds have the same influence on anyone who hears it, no matter what age you are, what sex you are, what culture you were brought up in, what language you speak; womb sounds fit that criteria.

M&B: Why is it sound, but not the vision?

Because at 16 weeks, when the fetus is very small, the nervous system is developed enough that all the senses are functioning; however it is dark, so the eyes aren’t working, no information is being received and the nose and the mouth are filled with fluids, so there is no tasting or smelling, but sound travels through water five times better than it does through air; therefore the ears are working but amplified by five times, and the largest sense organ we have, the skin, is a huge sense organ for vibrations. Thus, we’re experiencing vibration and sound for nine months in the womb and that sound environment is a very specific type of environment; the amniotic fluid sounds, the watery bubbly sounds, the mother’s heartbeat through the placental artery, respiratory sounds from the diaphragm, noises of the internal organ; it’s a rich complex, three-dimensional sound environment that is exactly the same for everyone of us; we all experienced this in the same way.

M&B: How does the fetus perceive this sound?

Remember the fetus is small and the ear is small; the eardrum is extremely small. If the eardrum was blown up to the size of my eardrum and the mother’s heart was blown up in proportion it would fill this room. So what kind of sound would such a heart make? It wouldn’t be the sound that you would expect it to be listening to the adult’s heart with a stethoscope from the outside; it would be a very large, slow sound, a large thumping sound.

M&B: How is this related to the use of sound in therapy or for relaxation?

Most of us who have gone on vacations and have explored nature feel a peaceful, beautiful return to nature; why?

Because if you take the sounds of the amniotic fluid and you slow those sounds down, they sound a lot like the ocean. The size of the sound waves compared to the eardrum would make these watery sounds sound like they have also slowed down. So many of the watery sounds in the womb sound like other sounds that we can hear later in nature. This can spark a similar kind of primordial recognition which is beyond the control of the rational thinking mind.

So when we build up these kinds of sounds on a soundtrack you can then push the button and the body will automatically go back to what it felt like to have a natural experience; when we combine the sounds of nature with music this makes a relaxation tape. So I would say that the sounds of nature provide secondary primordial sounds, as not all of us would have heard the same natural sounds in our lives.

The idea is to extend the power of the primordial recognizable components of sound in order to create a physical response. The technique is to connect with a primal recognition at a subconscious level; this will tap into experiences that you have had in the womb and at other times.

M&B: You not only use sound for relaxation, but also in order to combat stress. Could you please talk about this?

When a person has a fight-or-flight response, a stress response, we know very precisely what happens physiologically. The very first thing, the most sensitive organ, to respond to stress is the heart and thus when we look at the heart waves we can gain important information.

M&B: Why the heart and not the brain?

The reason for this is that the heart is the perfect system in the nervous system; it is called the autonomic nervous system or the automatic functioning nervous system; it knows how to organize and control my organs and glands and body chemistry and perform biomechanics that I’m not aware of and can’t control.

My rational-thinking brain can control physical body movements and thinking processes, but there’s another section that controls the automatic functioning of how my body runs. There is another control of this autonomic nervous system, which has two large branches of nerves that innervate all the organs and glands; these two branches of the nerves are the sympathetic and the parasympathetic nervous system.

While the sympathetic nervous system switches on, the parasympathetic switches off and mobilizes energy from the higher brain centers, from my digestive system, from my elimination system and from my immune system, it pulls that energy into my muscles to fight for my life.

This is when the brain freezes when you take an exam. You’re frightened about the exam; it is your final exam and you’re frightened that you’re not going to pass it or that you’re not going to do well. That fright causes the sympathetic system to switch on and drain the energy out of your brain; this is a self-fulfilling prophecy. You don’t have a brain left, because all the energy has gone to your muscles. At the moment the sympathetic system switches on, it mobilizes the pituitary which signals the adrenal glands; these fires adrenaline, the adrenaline starts the heart and the respiration and a number of other things. At the same time it suppresses the pancreas and lets loose extra glucose so you can fight for your life more and so what you end up with is the very first thing that happens.

M&B: What is the normal stress response and how do we return to a normal state?

When a person is required to carry out special tasks, like running or fighting for one’s life, then the sympathetic nervous system has to switch on, mobilize the energy from various places and send it to my muscles. If I am injured, but I survive and win, then the parasympathetic system is going to switch on and build up; that energy will be sent to my immune system, healing centers and recuperation areas for my muscles; when this is finished these are basically switched off, because we don’t need this energy anymore. This is certainly the normal way of functioning.

Thus, there are certain normal ways in which the body should function when a person is okay and normal. When the patient comes in and lies down on their back we hook them up and look at what’s happening in the autonomic nervous system. Normally when you lay down for three to five minutes your system should relax. Gravity isn’t affecting you, your heart doesn’t have to do extra work to pump the blood up to your brain; as a result the muscles relax and the sympathetic system and parasympathetic nervous systems should be at a level playing field. Now they can conserve their energy and this state of balance in the autonomic nervous system is known as homeostasis. The best state of health you can have is in homeostasis, where you’re not using energy in an unnecessary way. Homeo means unity, one, within my body, while stasis is a perfect state of rest.

M&B: What are the results of your studies to date? How many of us return back to homeostasis in three to five minutes?

Clinically what I see is maybe two patients with a normal response; I’ve been checking every patient with the real time heart rate variability system now for 7 years. This means thousands of patients; in all of that time I have seen one, maybe two patients with a normal response. I hook the patient up, and see what the response is. Most people’s response is abnormal; what this abnormality says is that after five minutes they have not attained a balance, and they have a good strong, healthy, dominant sympathetic stress response which never stops.

M&B: What do you think is the reason for this?

This state is constant because of the artificial, extremely stressful world that we have artificially created for ourselves. It wasn’t supposed to be like this; you are supposed to wake up in the morning and grab your spear and go catch a rabbit and that’s your workday; when you get there and you see that rabbit the sympathetic system turns on and the heart rates increase, the same thing happens with the rabbit, and it’s all going to be over in a couple of minutes. You’re going to catch the rabbit or he’s going to get away and then everything goes back, the clutch pushes in. Let’s say you get the rabbit, and the clutch pushes in; everything is fine and you are going to go home. Now you hear a growl behind you and there’s a saber tooth tiger looking at you, thinking about dinner; now the sympathetic system switches on, the heart rate is up, and you are running and he is running. It is all going to be over in a couple of minutes and either you are going to get away or you’re not.

But what I’m talking about here is that the nervous system, at its core, and its stress response are both designed for a sprint and not a marathon; but what we have had in the twenty-first century and throughout the twentieth century is a marathon of stress; but these are the kind of stresses that we can’t see, i.e. invisible stresses. They’re electromagnetic frequencies; the walls in this room, television channel frequencies, military frequencies, microwave frequencies, air pollution, food pollution and traffic jams when going to work to a job that doesn’t pay enough money for a boss who has the emotional development of a three-year old are all problems for us. The stress goes and then it’s back again; it’s time to get dinner for the kids and watching 7:00 news. This doesn’t stop; the nervous system’s solution to surviving this is to invent a mechanism of merely stepping on the gas, switching on the emergency sympathetic system on and bulldozing your way through the stress for the rest of your life with great momentum; but at nighttime, when it’s time to go to bed the nervous system doesn’t want to let go of this momentum that it has built up to get through the day.

M&B: And this has devastating effects on our health?

You can’t keep running in high gear for the rest of your life without some horrible consequences; the body’s not designed for it. You can only do this for a few decades before your heart or your brain blows up, the two biggest killers in Western society are heart attacks and strokes – there is also high blood pressure and diabetes. But what can we expect if our sympathetic nervous system is all the time working, which means by definition that our heart pressure is up and the pancreas is suppressed, so there is extra glucose being sent out? So people who don’t have the constitution to handle the stress blow a fuse; they have no way to handle the stress and as a result they have immune system problems, digestive problems, and problems that come from that colon cancer, irritable bowel syndrome, autoimmune diseases, allergies.

M&B: You are using sound in order to help people return to their normal healthy state. How does this work?

I’ve come up with a way to use sound to force the autonomic nervous system to push in the clutch, removing us from a place of high stress from which you can leave by using sound; we do this by using the heart-rate variability to see how bad the heart rate is and then explore various precisely tuned sound frequencies which will actually force the nervous system to push in the clutch. There will be a very specific tone for every person; this is like a glass vibrating if I sing the right note. An opera singer can sing the right note to make the glass vibrate. Well, now let’s imagine that your autonomic nervous system is the glass and we’re going to explore various sound frequencies that are very precisely tuned to find out which one affects your autonomic nervous system function; when we find it the response will be like pushing in the clutch and sending it into a state of relaxation. So we hit the right note and we get the response; this is what I’ve been looking for. Now we can see this phenomenon clinically. Once we’ve got the tone that’s associated with the pushing in of the clutch of the autonomic nervous system we can use that therapeutically through a specially designed sound table that I have made; this consists of low-frequency sound components which drive the low frequencies right into your cells via headphones. This relaxation mode is introduced to your nervous system over an extended period of time. We can burn this sound onto a CD and you can take it home and work with it at home on your stereo; it is like an internal training program. Every time your nervous system pushes in the clutch, the ability to push in the clutch grows, just like working a muscle in a gym.

This is a kind of high-tech stress reduction training program for the nervous system with sound. This is one of the three components I mentioned earlier; there are three parallel processes using sound for healing. This one is the idea of using the physical resonance to cause an effect on the nervous system to relax people.

M&B: This is what is called a sound table, right?

Yes, the sound table I needed had to have specific requirements, which is why I had to make my own to attain the exact clinical results I wanted. The power in the table actually delivered more power to your body than I wanted to be delivered. Therefore, I had to be able to have the sound that was coming from the table split into the right and left speakers, but none of those that were available on the market could do that. So I had to have it specially designed. As a composer, musician and audio engineer I was able to design the sounding board of that table and the transducers so that a lot of free sound could be delivered and spread out, therefore it is much more effective and delivers the sound to your body via headphones. Thus there is a lot going on in that table that you cannot see and this is what makes it work properly.

Interview conducted by Mustafa Tabanli for Ebru TV for the Emmy Award winning television series Matter and Beyond.

In a healthy body, all of the involuntarily functioning mechanisms seem to know what to do, at the right time and in the right amount. But are these systems really “autonomous,” doing what they will? Can it be coincidence that each time the perfect choice out of thousands of possibilities is made?

Regular controlling mechanisms are needed for our bodily activities to function properly. This duty has been given to the nervous system. The autonomic nervous system (ANS), which is in charge of controlling the vital functions of the body, is designed to function in an involuntary, reflexive manner. The operating systems of several machines that make our life easier are developed by being modeled on the ANS. Take an air-conditioned car with a thermostat for example. When the air is cold, a heat sensitive mechanism automatically starts and it provides the engine with more gas and it produces more energy. And when it is warm enough inside the car, this time the thermometer urges the system to reduce the gas-flow back to normal. Likewise, sympathetic and parasympathetic nerves placed in the autonomic system are given the duty of a regulator that restores the altered functioning of organs back to normal so that they do not upset the balance of our body.

If the light coming to our eyes is too bright, vision is blurred. When the retina is exposed to excessive stimuli this causes the parasympathetic nerves to send signals to the eyes to contract the pupils so that the sensitive layers of the eyes are protected and the vision is cleared. In darkness or under dim light, the sympathetic system is called to duty again and this time the pupils are enlarged. The sympathetic-parasympathetic (autonomic) nervous systems granted to human beings play a role in optimizing eyesight under differing intensities of light.

Parasympathetic nerves are created in a way to stimulate the saliva and tear glands, as well as the glands in organs like the nose, stomach, intestines, pancreas, etc. When the secretion in these glands is surplus to our requirements, the canals in connection with them are shrunk and the secretion is lessened. Without such a system, germs would boom, morsels would not soften in our mouth, food intake would not decompose in our stomachs, the gastric mucus which protects the inner stomach from acid would not be secreted, and the final stage of digestion, absorption of digested nutrition, would not happen. Likewise, if our tear glands did not function, sores would emerge on our eyes; if there were no nasal mucus, dust and germs suspending in the air would easily reach our lungs.

The physiological functioning of the lungs and their protection are also maintained through the sympathetic and parasympathetic systems. When our tissues need more oxygen, the sympathetic system is activated. The air sacs are enlarged and more air is let in. If toxic gases, dust, cigarette smoke or other harmful elements enter the respiratory tract or the lungs are exposed to any destructive matter, the air sacs are narrowed by the immediate intervention of the parasympathetic system. In this way, the secretion in the air sacs increases and the harmful substance is prevented from going deeper into the lungs. Then the harmful substance is thrown out through secretion and the reflex of coughing.

When the blood pressure drops below 50mm Hg for any reason (due to hemorrhage, medication, body position, etc), the sympathetic system immediately works to send blood to the brain and the heart. As these are the most vital organs, they are given priority at receiving blood. Our blood circulation is carried out within a closed-circuit system and there is a constant amount of blood. Therefore, sending an organ more blood means lessening the blood sent to other organs. To maintain this, the sympathetic system again works to cause narrowing. When food intake reaches the stomach, the parasympathetic system is stimulated to enlarge the relative veins. More blood is pumped to the stomach.

Everything in both systems is designed to protect the organs, tissues, and systems; in other words, the entire body. When a person’s blood pressure goes up, the baro-receptors, which help regulate the pressure in the veins, are stimulated in order to ward off the danger and the narrowing effect of the sympathetic system on the veins is taken under control. In this way, the pressure applied by the blood to the walls of the veins is eliminated. During physical exercise or in a state of stress, anxiety, or worry, the tissues use more oxygen and the sympathetic alarm is switched on.

Blood is pumped faster to meet the need of the tissues. During sleep, the body needs less energy and the metabolism is slow. Therefore, a slower heartbeat is required. During a time of distress or fear, the sympathetic stimulators are under pressure due to hyperventilation. Then the parasympathetic system is put into service and the heartbeat and the blood flow to tissues slow down.

Sphincters are ring shaped muscles that maintain the constriction of a body passage or orifice. With sympathetic signals they constrict and block the passage, and the parasympathetic signals ease them to open the way. If it weren’t for the sympathetic system, the urine produced in the kidneys would not be under control and we would wet our trousers. However, what happens in practice is that when the kidneys produce a certain amount of urine, two sphincters controlled by the sympathetic system contract and they prevent an untimely emptying of the bladder.

Similarly, there are sphincters in the gastro-intestinal tract. If the sympathetic system had not been given the duty of controlling them, the food we eat would not stay with us until it was absorbed and it would be disposed of immediately. On the other hand, the malfunctioning of the parasympathetic system would cause obstructions and we would suffer greatly. Take the parasympathetic system working in our urinary tract for instance. It works without our control and if it did not work, the urine collected in the bladder would press back on the kidneys and cripple them.

In some functions, like the breaking down of fats, ejaculation, increase in brain activity, or the contraction of skeletal muscles, the parasympathetic system is not involved. Since its involvement might harm the body, it is not given a duty here, and the sympathetic system on its own suffices.

There are several other functions carried out by the autonomous nervous system. It works without our will or conscious control. As humans we tend to claim: “I did this, I did that.” When you eat something, your conscious control is limited to chewing the food and swallowing it. We cannot tell our stomach to digest or not to digest the food. In a healthy body, all of the involuntarily functioning mechanisms seem to know what to do, at the right time and in the right amount. But are these systems really “autonomous,” doing what they will? Can it be coincidence that each time the perfect choice out of thousands of possibilities is made? Is it at all possible for these fascinating systems to be a just a work of random causes?

The discipline in which medicine and engineering truly meet and face new challenges is the field of “biomedical engineering,” an emerging discipline that is only a few decades old. In each sub-specialty of biomedical engineering, researchers study the human body, develop new materials and structures using engineering sciences, either as a treatment method for disease (e.g. artificial bone implants, artificial blood, vascular stents, cardiac valves, etc.) or to diagnose them (e.g. imaging methods and other diagnostic instruments in hospitals). Biomedical engineers face the incredible challenge of developing materials and devices that are compatible with biological systems and capable of working inside the human body to substitute bodily functions. Needless to say, the extreme complexity of the human body makes it impossible to mimic the original system or function of the organs in any way. However, even a poor replacement part or a functional improvement provides great benefit to the patients.

One of the most complex systems of the human body is the nervous system, which consists of the central area (the brain and the spinal cord) and the peripheral parts. The branch of biomedical engineering that deals with the nervous system is “neural engineering.” In this article, we will touch upon a specific subject in the broader area of neural engineering, that is, “neural prosthetics.”1 As the name implies, neural prosthetics is an area where engineering knowledge is utilized to treat neural disorders.

The building blocks of the nervous system are called “neurons.” Neurons generate electric pulses to communicate with each other. The fact that these electric pulses can be elicited by artificial means, i.e. by applying small electric currents to the neurons externally, forms the very foundation of the field of neural prosthetics. Neural engineers can input information into the nervous system by taking advantage of this phenomenon, called “neural stimulation.” Likewise, the information content of neuronal activity can be deciphered by recording the electrical pulses from the neurons and interpreting them according to neuronal function. This two way traffic, monitoring and controlling the neural activity, allows researchers in this field to develop methods of treatment for some sensory, motor, and psychological disorders.

Some of the most successful neural prosthetic applications have been in deep brain stimulation in Parkinson’s disease,

cochlear prosthesis in hearing impairment, bladder emptying and respiration in spinal cord injury, and vagus nerve (10th cranial nerve) stimulation in epilepsy and psychological depression. These are neural prostheses that are readily available as a treatment method for the given ailments. There is a whole host of others that are in the research and development phase. We will review a couple of examples.

In certain diseases of the inner ear hearing is lost as a result of damage to the hair cells inside the cochlea. In normal cochlea the sound information reaches these hair cells after traveling through the ear drum (tympanic membrane) and the structures of the middle ear, causing them to vibrate. This vibration of the hair cells is mechanically transported to the spiral ganglion cells that form the hearing (auditory) nerve. The hearing nerve carries the sound information to the brain in the form of electric pulses. The ganglion cells are healthy and functional even if the entire population of hair cells has been lost as a result of disease. Neural engineers take advantage of the fact that the spiral ganglion cells (which normally accept input from the hair cells) can be electrically stimulated, thus mimicking the function of the hair cells and producing the sensation of sound.2 During a simple surgical operation, the surgeon inserts an electrode into the ear canal which spirals into the lumen of the cochlea so that the sites where the electric current emits from the electrode are adjacent to the spiral ganglion cells (Figure 1). To summarize the principle of the operation; the audio signals are captured by a microphone, processed, converted into electric pulses (A in Figure 1), and transmitted to the implant over a transmitting antenna (B in Figure 1), or headpiece, held in place by magnets. The implant (C in Figure 1) applies the signals to the ganglion cells in the cochlea through tiny electrodes (D in Figure 1). The hearing nerve (auditory nerve) carries the sound information to the brain, where it is “heard.”

Even though the human spiral ganglion has tens of thousands of nerve cells that provide a rich sense of hearing, the cochlear implant, using only six stimulation contacts, can produce auditory perception with sufficient fidelity to enable a deaf individual to use an ordinary telephone.3 Individuals with cochlear implants can also improve their hearing with practice. Thousands of patients have been implanted with cochlear prostheses to date, including children.

The second neural prosthesis application we will review is the retinal prosthesis, which, unlike the cochlear implants, is still in the research phase. Retinitis pigmentosa and age-related macular degeneration both lead to photoreceptor degeneration in the eye and result in a significant visual deficit or blindness.4 A growing body of research supports the feasibility of replacing the function of the photoreceptors with an electronic device. 5–7 A retinal prosthesis is analogous to the cochlear implant in many ways. In a healthy retina, the photoreceptors initiate a neural signal in response to light. In a retinal prosthesis, electrical pulses are utilized to initiate a neural response in the remaining cells of the retina, the bipolar and ganglion cells. It is hypothesized that the perception of shapes and images will be possible through pattern stimulation of the retina. Initial results are encouraging, but the quality of vision that can be attained with this approach is still a question to be answered. A conceptual retinal prosthesis system is shown in Figure 2. The system consists of an external unit coupled to an implanted stimulator with a wireless link. A video camera in the external unit captures an image and converts it to digital data. The implanted unit receives the signal, recovers power and data from the signal, and generates the stimulating current. The stimulus pattern is applied to the retina via the electrode array, which contains distinct electrodes that interface at many locations on the retinal surface. Recent implants in human subjects suggest the feasibility of this approach where individuals attain perception of bright dots in the visual field called ‘phosphenes.’ Furthermore, blind subjects are able to perceive edges when a few of these bright dots are lined up in their visual field.

Figure 3: A conceptual diagram of a Brain-Computer Interface for high level spinal cord injury or patients with ‘locked-in syndrome’ (adapted from Wolpaw et al., see note 9). The recorded neural activity from the motor cortex is processed and converted into command signals to control, for instance, a wheelchair, or to generate electrical signals to activate hand muscles for grasping an object.

Both cochlear and retinal implants are sensory prostheses, i.e. aids for sensory impairments. Another family of neural prostheses deals with motor impairments. Severe motor disability results from high level spinal cord injuries (quadriplegia) where most of the body is paralyzed, sparing only some face, neck, and shoulder muscles. Quadriplegic individuals are in extreme need of a means to control their environment; they need to be in control of their wheelchairs, bed, the room temperature, lights, TV, etc. Because of the level of paralysis it is impossible for them to generate any control signal, except perhaps by sipping or puffing on the end of a tube, which produces a very poor control signal. In the case of a ‘locked-in syndrome’ the condition of the patient is even more serious, with only some functions remaining in the facial muscles. The term ‘brain-computer interface’ has been coined to refer to attempts whereby the motor output of the brain is recorded and interpreted to generate the control signals needed by these patients (Figure 3,9). The ultimate objective of this research will be accomplished when the patients are able to control anything they need to control in their environment, including a computer. The brain-computer interfaces vary in the invasiveness of the approach. The least invasive methods utilize the electroencephalogram (EEG) signals recorded from the scalp. Unfortunately, the signal quality is poor and only ‘on/off’ type of command signals can be generated using this method. In the most invasive, yet most successful applications, an array of electrodes is implanted directly into the motor cortex of the brain at a depth of a couple of millimeters. The recorded signals contain volitional information as the patient makes intentions to move their arms or legs. These signals can be controlled by the patient, and they can in turn be used to control their environment. The current level of success in this type of BCI allows the user to have three dimensional control of a robot arm. This is of invaluable benefit to a quadriplegic individual.

Concluding Remarks: Reflections on Divine Wisdom

Even the subtlest parts of the nervous system are extremely complex. Just to name a few examples, from the highest centers in the brain down to the skeletal muscles in a descending order; the neural circuits of the short-term memory in the hippocampus, fine motor control circuits of the cerebellum, central pattern generators in the spinal cord, and even the control of skeletal muscles in graceful movements of the limbs are impossible to reproduce by artificial means. The Seal of Divine Design is clearly visible in these neural systems, as they are far more complex, far more compact, and far more functionally efficient than any system engineered by mankind. If anything, the growing experience in neurosciences teaches us that the vertebrate nervous system is full of wonders of engineering design. Therefore, it is a great blessing to be a student of both neurosciences and engineering disciplines. This bestows neural engineers with a unique perspective to understand the beauty embroidered into the human nervous system and contemplate on the Divine Wisdom. In spiritual terms, we may think of the human nervous system as a window opening to the works of Divine Wisdom, with manifestations of His Beautiful Names at the brightest level. It is an overwhelming joy to be able to open this window a crack, once in a while, and take a little peek.

References

1. Wise, K.D. ‘Silicon microsystems for neuroscience and neural prostheses,’ IEEE Engineering in Medicine and Biology Society Magazine, vol. 25, no. 5, pp. 22- 29, Sept.-Oct., 2005.
2. G.E. Loeb, ‘Cochlear prosthetics,’ Annu. Rev. Neurosci., vol. 13, pp. 357–371, 1990.
3. J. Helms, V. Weichbold, U. Baumann, H. von Specht, F. Schon, J. Muller, B. Esser, M. Ziese, I. Anderson, and P. D”Haese, ‘Analysis of ceiling effects occurring with speech recognition tests in adult cochlear-implanted patients,’ ORL J. Otorhinolaryngol Relat. Spec., vol. 66, no. 3, pp. 130–135, 2004.
4. E.L. Berson, ‘Retinitis pigmentosa. The friedenwald lecture,’ Invest Ophthalmol. Vis .Sci., vol. 34, no. 5, pp. 1659–1676, Apr. 1993.
5. E. Zrenner, ‘Will retinal implants restore vision?,’ Science, vol. 295, no. 5557, pp. 1022–1025, Feb. 2002.
6. J.F. Rizzo III, J. Wyatt, J. Lowenstein, S. Kelly, and D. Shire, ‘Perceptual efficacy of electrical stimulation of human retina with a microelectrode array during short term surgical trials,’ Invest. Ophthalmol. Vis. Sci., vol. 44, no. 12, pp. 5362–5369, 2003.
7. M.S. Humayun, J. Weiland, G. Fujii, R.J. Greenberg, R. Williamson , J. Little, B. Mech, V. Cimmarusti, G. van Boemel, G. Dagnelie, and E. de Juan, Jr., ‘Visual perception in a blind subject with a chronic microelectronic retinal prosthesis,’ Vision Res., vol. 43, no. 24, pp. 2573–2581, 2003.
8. Weiland, J.D. and Humayun, M.S., ‘A biomimetric retinal stimulation array,’ IEEE Engineering in Medicine and Biology Society Magazine, vol. 25, no. 5, pp. 14-21, Sept.-Oct., 2005.
9. Wolpaw J.R. et al., ‘Brain-computer interfaces for communication and control,’ Clinical Neurophysiolology, vol. 113(6), pp. 767-791, 2002.

Programs and documents on the computer are held in two areas: software and hardware. For scientists, one of many goals is to make the processors or chips, which are like the human brain that consists of nerves, much smaller, but still powerful enough to process many more calculations. There are many differences between the current chips and earlier ones. Chips which will be produced in the future will be smaller and probably process more calculations more quickly.

Programs, which can be seen as being the mechanical counterpart of the human mind, bring the above-mentioned improvements into daily life. New programs boost the capability of the computer in parallel with the capability of their chips. Without these programs, computers would be no more than ordinary electronic machines.

Developed technologies in fields like industry, communication, or the military bring us face to face with new developments and have made the computer an undeniable part of our lives. Mobile phones equipped with new features, medical machines which can easily make a large number of analyses and provide ease in diagnosis and treatment, robots that can operate with minimum error and have a low cost when used in production, and weapons that automatically focus on the target are all part of this progress.

With time, software and hi-tech sensors have enabled computers to communicate with people; there are now systems that are controlled by the voice, which are able to recognize a person from their iris or fingerprints, control systems which are carried out by touching a screen, etc. Such systems are operated with the help of special sensors or by some signals that carry messages from the person or the environment to the computer. The most important feature of these sensors is that the signals produced at the output are very weak and there are few differences between them. An ATM can recognize a particular person’s iris, thanks to the ability of its computer to compare the signals from the ATM’s iris scanner with previously recorded data. In this process, the computer uses the small differences that one person’s iris has to another’s. In this or similar systems, complicated programs are used, called “expert systems” or “artificial intelligence”. These programs imitate human senses, but they aim to operate with an even keener sensitivity and clearer criteria.

A question that is a subject of fiction comes to mind; “Will computers vie with or even fight with human beings?” In the mid-term, the rapid development of technology will create computers which can communicate with humans, which can understand them, and put forward ideas. A negative outcome of such a situation depends, once again, on man. Such a horrific situation could be the result of technology that can cause environmental disasters; this technology is almost identical to the one that we have described above. If we are able to establish an understanding of “civilization” which does not ignore human values for the sake of technological development, then such fears will be groundless.

Artificial Nervous Systems

As we all know, people have imitated nature in many of their inventions. In a way, artificial nervous systems imitate how a nerve cell learns and how it works. Fuzzy systems however imitate how the judgment of a human being works, rather than the nerve cells of the brain. In these systems people try to form a decision making criterion by assuming that there are endless grey tones between white and black or by assuming that there are infinite values between zero and one.

The purpose of the research on artificial nervous systems is to understand how the brain operates, then to make a system that imitates it and carries out the same operations. Artificial nervous systems are made of simple nerve cells which are bound in parallel, called process elements; these allow for real objects to be seen as if they were biological systems.

Here, the program that resembles the nerve cell operates in the same way as a nerve cell. The main part of a nerve cell is formed from the body, called a “soma”, an “axon” that is bound to the body and many “dendrites”. There are many “roots”, or synapses, on the dendrite of a cell which make contact with the dendrites of other cells. A nerve cell either transmits the electrical stimulus that comes through the axon to the other nerve cells through the synapse, or it does not transmit it, depending on whether or not the signal is over or below the threshold value. So a nerve works by itself, but its activity becomes meaningful when working as a part of a nervous system. It would be useful if we consider how the learning process occurs here. It is thought that the required data are stored in the memory center and this fact is taken as a model for some artificial nervous system software that has been successfully developed to date.

A nerve cell and the process of transporting signals from one cell to another can be written as software. It is clear that a natural nerve cell is more complex and that it is bound to more cells than an artificial one can be. The number of communication ports (synapses) of a natural nerve can vary from between 1,000 to 10,000.

An artificial cell produces output if the input value is over the cell’s threshold value; if this is not the case then there is no production. If there is output – as in natural cells – then this output is transported to the next cell group. Each cell produces its output as an input for the next cell.

A cell is separated into three groups: input, the hidden layer and output. Each group is considered to be made up of one layer, while the hidden layer can consist of more than one, according to the complexity of the job. As can be seen, the placement of the layers is similar in the process of the human body. We can compare the cells on the input layer with human senses. In this way we can teach a robot to avoid heat and cold, we can make them see and act according to this information. (Do not forget that a robot is in fact a computer.) It is natural that some sensors must be bound to the cells on the input layer. For instance, a sensor which is sensitive to heat can make the robot react to heat when the temperature is over the limit value or when the temperature is dramatically low it can move closer to a heat source. Or if pictures received from a video-camera are similar to an object that has been fed into the robot such data input can cause the robot to move to that object.

Artificial nervous systems are not only used in robot applications. They are commonly used in making clinical diagnoses, determining market-customer profiles, recognizing voices or pictures, classifications such as determining micro-structures, like germs and cell materials, economic profiles, energy sources, the futures of market shares, some predictive sciences, such as weather forecast, zipping data for computers, process control in industry, checking resources and some other matters in technological areas. As can be seen, there are many application areas for artificial nervous systems, all of which differ from one another.

The Basic Features of Artificial Nervous Systems

The features of artificial nervous systems can be simplified as follows: firstly, they can learn how to solve problems. In order to do this they use sample data and learning styles and while doing this they do not require any special help. Secondly, they can recognize important features and relations to help them distinguish different data forms.

When an artificial nervous system is operated, the first thing to be carried out is the training process. In order to do this, the program needs to have two alternating operations. It may obtain information concerning some results to be achieved, using results that come from the user, or the program is itself asked to produce some results. These two types of learning are not very different from how a human learns. One shows a young child an animal, and repeats the name. Now the child has learned the name of the animal and correlates it with the picture of the same. If no one teaches a child what a bird is, the child will all the same classify all animals that have wings and beaks and that have a certain physical shape, maybe even creating a name for the animal by him/herself. The difference between the computer and the human in this process is that a human has the ability to judge, while computers classify the animals according to their shapes and groups them thus. Naming and giving a naming feature to the computer is again a decision that a human will make. When the training process is finished, the data can be entered into the computer and the desired results can be attained.

Artificial nervous systems are changing and developing day by day. With each new development they become closer to the human nervous system; they are able to recognize different characteristics of different people and they are learning to make sorting decisions, even limited judgments. Whether or not these machines may one day enact a nightmare scenario, taking over from us is not a great threat, as whatever they are capable of doing is up to us to decide, as their “masters”. We should not fear these systems, but try to develop more of them; such systems help us in every day tasks, from drawing money out of the bank to our annual check-up at the doctor’s.

The field of medicine, as one of the oldest fields of scientific inquiry, has been particularly rich in examples of changing theories. Aristotle (384-322 BC) thought that the brain was a device used for cooling the blood. By contrast his teacher Plato (427-347 BC) had thought that it was the ‘originating power of the perceptions…’ Yet today scientists accept Plato’s older theory. In the 1800s the state of the art brain science was phrenology, attributing certain aspects of human character to bumps and ridges on the skull. This is frowned upon today as mumbo-jumbo. However, it must be remembered that at the time it was considered as a hard and fast observational science. It was not until 1861 that Paul Broca refuted this ‘science’ by attributing language to a certain region of the brain, since referred to as Broca’s area. Even so, phrenology continued to have its adherents and practitioners until the early 20th century. Many of the current theories of thought, emotion, psychology and psychiatry are based on observations only slightly more reliable than those made by the phrenologists. The tools used are more expensive (e.g. CT, M RI and PET scanners) but the basic approach is comparable to that of the phrenologists.

Currently a revolution is taking place in biomedical science. ‘This revolution centres upon (aptly named) free radicals’. The most famous of these is nitric oxide (NO).

Nitric oxide is a noxious chemical spewed out by car exhausts and power stations. For years it was considered to be one of the most poisonous gases known to man. However, in the 1980s scientists discovered that many cells of the body also produce nitric oxide. Hundreds of research papers have been produced in recent years investigating this short-lived compound. It is currently a more popular research topic than AIDS, Alzheimer’s and arthritis. NO has revolutionised scientists understanding of blood pressure and the whole manner by which cells communicate.

It is thought that when released by the body in minute amounts it is capable of carrying biochemical signals from cell to cell resulting in a whole array of bodily events. In circulation NO helps to control the bore of the blood vessels and hence blood pressure. In the nervous system it is thought to be implicated in memory. In the immune system it purges both foreign bodies and tumour cells. The medical profession have realized NO’s importance in many conditions not just high blood pressure but also stroke, septic shock, clotting disorders and even impotence.

The mode of action of NO is its most controversial aspect in terms of traditional understanding of cell biology. To start with NO is what chemists call a free radical. This means that it carries an unpaired electron and is therefore highly reactive, unlike any other molecules in the body’s well- documented and well-balanced signaling system. NO liberated from cells is converted within a split second to nitrogen dioxide NO2 by combining with oxygen. Most of the both’s other communication molecules are complex by comparison, molecules such as amino acids, catachol amines and small peptides. These conventional message transducers deliver signals by latching on to specific receptor molecules. A classic example is the catachol amine adrenaline latching onto beta receptors. This is usually described by a lock and key analogy. The mechanism of NO goes against this completely by penetrating cells directly. Once inside cells it stimulates the production of a small nucleotide called cyclic guanosine monophosphate or cGMP. This cGMP induces a host of functions ranging from muscle relaxation to slowing down blood clotting.

The importance of NO was first discovered in the regulation of blood pressure. NO was found to cause blood vessels to dilate by relaxing the muscles in the vessel walls. Blood vessels are made up of layers of muscular, elastic and fibrous tissue, and have a lining called the endothelium. The endothelium releases NO which drifts into the surrounding layer of muscle. There it triggers the events that make the muscle relax at the diameter of the vessel then widens. This process is controlled by the mechanical effect of the blood flow. When blood rushes over the cells of the endothelium it causes them to distort slightly. This distortion results in the release of NO. From this it can be seen which in turn sends messages to the vessel walls via a whole arm of receptors and transmitter muscles. The balance between the central nervous control and local control is not well understood. For years doctors have used drugs that affect the nervous control to lower blood pressure with apparent success, for example beta receptor blockers. However the result of the various NO experiments indicate that the nervous system is comparatively insignificant in the regulation of blood pressure. The mysteries of beta-receptors and there complexities are far from solved, yet these are supposed to provide the scientific bases of high blood pressure tablets, such as beta blockers. ‘There must be a continued balance between these two powerful forces. – the local vasoconstrictor control and the central vasoconstrictor control.’ says Sir John Vane, of the William Harvey Institute, London.

The theories of circulatory control have been revolutionized by one man. Salvador Moncado, who first documented the role of NO in blood pressure and clotting: ‘We worked for hundreds of years thinking that the arterial system is a system of resistance vessels, when conductance is probably the better concept to use – which is the inverse of resistance. ‘This has resulted in a conceptual reversal of all research in the field of high blood pressure. The novel theory has cast doubt on the mechanisms of all the blood pressure lowering drugs that have been used, and yet these drugs do appear to work. This has parallels with the use of the drug aspirin, which has been used for decades for various ailments, but theories of its mode of action were only documented in the late 1970s. What came first – human theories or the practical results? A current controversy is whether we should consider high blood pressure to be the result of too much adrenaline or too little NO.

Doctors have unknowingly utilized the NO system for years. Since 1867 amyl nitrite and nitro-glycerine have been used to relieve the horrendous heart pains experienced by sufferers of angina pectoris. Doctors knew that these nitrogen containing drugs dilated blood vessels and reduced blood pressure. But the exact biochemical Involvement in scientific research should always convince us that humankind has a very limited understanding of the universe and that most of the work done by us only involves giving names to existing phenomena.

Examples of this are not only confined to biology. A recent discovery has rocked the world of cosmology, with much more importance to Muslims. The data that have come back to earth from the Bubble telescope suggest that the universe is only 8 billion years old. Scientists consider these to be the most reliable data involving the most elaborate experiments performed by humans on this subject. Yet Big Bang theory calculations tell us that the universe is no younger that 16 billion years. The best real data tell us 8 billion years: the calculations from theory tell us 16 billion. The inadequacy of theories could not be more dramatically demonstrated.