Before anasthesia, even routine surgeries were painful and dangerous. Its advent has allowed for amazing advances in public health and patient safety.

Humanity has faced various kinds of health problems throughout history, and will be facing them until the end of time. Even someone who has not yet suffered from an illness, will almost certainly suffer from one in the future. Let’s take a moment to reflect on all the people who are currently undergoing treatment at hospitals in the hopes of curing an illness.

From time to time we visit close friends and relatives who have undergone such operations. We wish them health and talk with them a little. We ask them how the operation felt, how many stitches they have. They usually say, “They injected me with something and I don’t remember the rest.” Then they may show us their gall bladder, wrapped in gauze, or their kidney stone, which was removed. Have you ever pondered how it is possible not to feel any pain during these kinds of operations, or how it is possible not to remember anything?

Surgical practices have advanced so much in present times. Heart, liver, and kidney transplants are now commonplace, as are finger and arm reattachments. Anesthesia, which makes all of these operations possible and painless, is a great blessing. Even the small and simple surgeries performed just 150 years ago were very difficult for surgeons – not to mention very painful for patients.

In his famous book on physiology and treatment, The Canon of Medicine the renowned 10th and 11th century scholar, Avicenna (Ibn-i Sina) (980-1037), defines anesthesia as, “a numbing and a cooling remedy.” He gives pathophysiological commentary on the influences of anesthetics and analgesics, and summarized painkilling methods as following:

1. A mixture prepared from linseed and dill should be applied to the area of pain.
2. Decreasing the sensitivity of the area of pain by increasing the moisture of the area, or providing narcotics for sleep.
3. Providing cooling and analgesic and anesthetic medicine.

Biruni, another Islamic scholar from the 11th century, documented his work with analgesic and anesthetic medicine. One of his writings recommends boiling the root tubers of henbane, Mandragora, horned poppy (Glaucium flavum), and Iris, together with the attar of roses and vinegar.

In his pharmacological works of the 12th and 13th centuries, Samarqandi recorded the analgesic, sedative (calming), anesthetic, and hypnotic effects of opium, mandragora, henbane, lettuce, beaver testicles, aloe vera, and coriander.

During the end of the 17th century, in Italy, anasthesia was performed by preventing the patients from breathing until they lost consciousness, and then immediately performing surgery on the patient who had fainted. This was called the asphyxia technique. The surgeries performed were relatively easy, such as the cutting of an arm or leg. The surgeon who was fast was considered the best, because patients could wake up during the surgery – that is, if they survived the procedure.

Another interesting anesthetic technique was making the patient lose consciousness by hitting them on the head. The hitting had to be done, “Hard enough to break the shell of an almond but gentle enough not to destroy its seed.” However, a bitter truth is that many patients were killed during this process.

Many have suffered the consequences of the absence of anesthesia in the past. Dr. Warren, a professor at Boston’s Massachusetts General Hospital in 1846, had placed his operating room on the very top floor of the hospital in order to avoid disturbing others with the screams of the suffering patients. One day, while examining one of patient’s tongues with pliers and a scalpel, he pulled the tongue of the patient without warning, and cut off his tongue with the scalpel. Afterwards, without hesitation, he cauterized his patient’s tongue with a hot iron. Dr. Warren observed the screaming, moaning, and suffering of the patients with no sign of emotion. He did not seem disturbed, and this was the exact attitude he needed in order to perform his duty. However, years later when enough advancement was done in the area of anesthesia, he couldn’t hold back his tears during the first operation that was performed with anesthesia.

Surgeries performed without anesthesia were hard on surgeon and patient alike. During his studies, the English gynecologist, Doctor James Young Simpson, fainted while cutting off a breast and considered quitting being a surgeon. Prof. Dr. Robert Liston was a famous surgeon at London University College. Dr. Liston had a reputation for being rude, arrogant, and strong. But he had no choice: he was forced to cut off a leg in 28 seconds, as anesthesia was not yet developed.

As can be seen from these examples, the absence of anesthesia, and the incredible suffering of the patients, pushed surgeons to be incredibly fast and emotionally insensitive. This period of time defined surgeons as strict, insensitive, and despotic. This went on until 1846, when William Thomas Morton performed the first surgery with anesthesia.

Since then, anesthesia has made surgeries much easier for all involved. Today, the definition of general anesthesia is total or partial loss of sensation in a human or animal body before surgical intervention.

Usually, anesthesia is performed by injecting medicine into the blood, or by making a patient breath an anesthetic gas. First, the patient loses consciousness, and then, with the help of muscle relaxants, the patient is put in a state of paralysis. Artificial respiration is performed until the end of the operation with the help of breathing machines called ventilators. For this purpose, an endotracheal tube is inserted in the windpipe of the patient and they are hooked to an anesthesia machine. This feeds oxygen, air, and the anesthetic gas to the patient. The anesthesia doctor controls the patient’s breathing, blood pressure, and heart rhythm, as well as other various, vital parameters, and the fluids that will be fed to the patient throughout the surgery. By doing this, the continuity of the anesthesia is made possible. When the surgery is over, the anesthetic drugs are no longer fed to the patient. When the muscle relaxants lose their effect and breathing returns to normal, the endotracheal tube is taken out and the patient is taken to another room to wake up. This is where the patient opens their eyes; it’s almost like a re-birth.

The chemicals in cannabis, opium, and coca were the essence of the first drugs used for general anesthesia; they are still being used, partially, in modern times. These chemicals, and some synthetic chemicals like them, are used for anesthesia and can be used after surgery in order to soothe pain. Most of our contemporary drugs are mostly synthetic, and they require many years of difficult education to be properly handled. It takes four years of additional education, after medical school, for a surgeon to become proficient with anesthetics.

Medical research done in the last two centuries about the dosage and quantity of these chemicals has advanced the practice of anesthesia incredibly. All this research provides a very good answer to why drugs have been created. While surgeons use the chemicals extracted from cannabis, opium, and coca, and from the synthetic chemicals like them, as a service to humanity, it is really hard to understand why some ill intentioned people use them for the detriment of human health.

There are lots of interesting examples of how plants communicate with insects. For instance, in self-defense against insects eating its leaves, a plant emits a volatile chemical that signals other insects, who are predators of those insects eating the plant. A byproduct of such insect communication may allow plants to signal danger to other extremely close, downwind plants. Professor of Entomology, Richard Karban and other researchers from the University of California showed that a cut sagebrush “told” nearby, downwind wild tobacco plants about its injury, and the tobacco plants apparently responded to protect themselves from damage. Over three seasons, researchers clipped leaves of sagebrush plants to mimic insects eating their leaves. The cut sagebrush released volatile chemicals (methyl jasmonate), which the wind carried to nearby downwind plants. The tobacco plants apparently sensed the chemicals-at least the tobacco plants increased production of a defensive agent-that caused their leaves to taste bad to insects. These downwind tobacco plants experienced less than half the leaf damage from grasshoppers and cutworms than control plants (Anon.). In one case study an acacia tree responded to browsing, or being beaten with a stick, by increasing the levels of tannin in its leaves within minutes. Amazingly, the tannin levels then rise in neighboring trees, and, due to its bitter taste, repel the browsers before they can do any further damage (Jacob 2001; Anon.).

What’s more is that plants can also talk to mammals. A study done by Professor Steven Johnson and his research team from the University of KwaZulu-Natal, South Africa, demonstrated how ground-dwelling mammal pollinators are attracted by a rare parasitic plant’s unique “perfume.” This specific floral aroma is comprised of over 30 compounds, especially ketones, fatty-acid derivatives, mono- and sesquiterpenoids. The three most abundant scent chemicals were 1-hexen-3-one, 3-hexanone, and ethyl butyrate. When the impact of these chemicals was tested on mice, it turned out that mice, like humans, find 3-hexanone to have a pleasant smell. The molecule is routinely used in artificial flavoring to produce a sweet fruity grape-like flavor. In addition, 3-hexanone has also been found in some bat-pollinated flowers, so it may be a general mammal attractant. Remarkably, scent cues are particularly important to plants pollinated by small ground-dwelling mammals because these animals are usually around at night when visual cues are less effective (Johnson et al. 2011; Anon.).

In addition to pests, plants have to deal with numerous microbial pathogens such as bacteria, fungi and oomycetes, and viruses in the natural environment. A proper response to pathogens can lead to resistance mechanisms that enable plants to survive. Plants can recognize potential pathogens by detecting pathogen-associated molecular patterns (PAMPs). This recognition activates a defense mechanism. A well-organized communication between the pathogen-invaded plant tissues and non-invaded ones is essential for the timely manifestation of defense mechanisms that limit the systemic spread of pathogens (Shah 2009). Salicylic acid, an important mobile signal, is transported from infected tissue to the rest of the plant body. It activates the systemic acquired resistance, which is a “whole-plant” resistance response that occurs following an earlier localized exposure to a pathogen. Plants not only communicate within themselves about a microbial invasion, they also talk to one another. For example, Tobacco plants warn each other against tobacco mosaic virus attack by releasing methyl salicylate, which is then converted to the protective salicylic acid in uninfected plants (Jacob 2001).

In contrast to harmful pathogenic interactions, there are also symbiotic, advantageous interactions between some microorganisms and plants. Establishment of such a beneficial symbiosis (which literally means “living together” in Greek) is complex. For successful infections, a molecular dialogue between partners is essential (Vadassery and Oelmüller 2009). Among these kinds of interactions, legume-Rhizobium symbiosis is of particular importance in agriculture, because by forming the symbiosis, atmospheric nitrogen can be used to sustain the growth of legume crops, such as soybean, pea, and bean, which occupy 12% to 15% of the land that can be used for growing crops throughout the world (Sugiyama, Shitan, and Yazaki 2007). Rhizobia are soil bacteria that fix nitrogen (diazotrophs) after becoming established inside root nodules of legumes such as alfalfa, clover, peas, beans, lentils, lupins, mesquite, carob, soy, and peanut.

Rhizobia require a plant host, since they cannot independently fix nitrogen (Anon.). Plant roots secrete signaling molecules (e.g. flavonoids) to attract Rhizobia. When Rhizobia sense these chemicals, they colonize around root tissues of the host legume plant. So, the rhizobial infection in legumes is an invasion by invitation (Murray 2011). The attached rhizobia secrete Nod factors, which are perceived by the plant. This initiates a series of events that leads to the formation of nodule, where Rhizobia fix nitrogen. Thus, Rhizobia make legume independent of soil nitrogen and the legume supplies nutrients to the bacteria. In addition, the legume plant supplies one critical component of nitrogenase, which is the key enzyme for fixing nitrogen. It all happens because the plant can talk to the bacteria.

The plant has many interests in being colonized by mycorrhizal fungi. Apart from providing nutrients such as phosphorus and nitrogen, the fungi protect plants from diseases, parasites, and other stresses. Plants even grow as much as 40% more when colonized. In laboratory experiments, carrots that were colonized grew 20 times more than the carrots that were not! In fact, they are such close “friends” that the fungus cannot live without a plant, and between 80-90% of all plants on earth are somehow associated with mycorrhizal fungi. The origin of this incredible friendship is communication (Montréal 2012).

As a result, plants can talk to microorganisms, pests, and mammals, but do they communicate with people? Are they intelligent creatures who can communicate with us? In 1848, Dr. Gustav Theodor Fechner, a German professor, suggested that plants are capable of emotions and that one could promote healthy growth with talk, attention, and affection. An Indian scientist, Sir Jagdish Chandra Bose, conducted experiments on plants in 1900. Bose found that plants grew more quickly amidst pleasant music and more slowly amidst loud noise or harsh sounds (Sir Patrick Geddes and Geddes 1920).

Moreover, according to Royal Horticultural Society, talking to plants helps them grow, especially if the one talking to the plant is a woman. Even though there are lots of divisive experiments done with plants to understand if they can talk to human beings, there is no serious finding about this subject yet. Even if, plant biologists do not currently know how to talk to plants, they strive to comprehend how plants communicate with other organisms in order to use this new and exciting language for improving the resistance of plants against pests or pathogens. Instead of using chemical pesticides, genetically engineered plant defense and communication pathways in crops are a preferred avenue.

Communication of plants with other organisms is such a complex problem. Plants can have a network with so many different creatures. They pass on information to each other or to other organisms that speak other languages. How did they obtain these amazing communication skills? Even the most advanced creatures, human beings, experience problems in communication, how can plants have robust communication systems in a heterogeneous environment?

The next time you hear a strange rustling among your garden plants, maintain distance. They might be having an argument. Plants also talk and they respond to attacks like we do. So, be careful and do not hurt plants as they might even curse or scream to you (Anon.).

Safiye Arslan is a research fellow in the area of molecular biology in Nevada.

References

• Adler, Frederick R. 2011. Plant signalling: the opportunities and dangers of chemical communication. Biology Letters. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3061173tool=pmcentrez&rendertype=abstract.
• Anon. Do plants talk? What are the chances it’s a boy? – USATODAY.com. http://www.usatoday.com/tech/columnist/aprilholladay/2006-07-24-plant-talk-baby-boys_x.htm.
• Anon. jacobson’s organ and the remarkable nature of smell. http://books.google.com/books/about/Jacobson_s_Organ_and_the_Remarkable_Natu.html?id=liKKQgAACAAJ.
• Anon. BBC – Earth News – “Perfumed” parasitic plant lures in pollinating mammals. http://news.bbc.co.uk/earth/hi/earth_news/newsid_9376000/9376474.stm.
• Anon. What is Rhizobia. http://www.bionewsonline.com/y/what_is_rhizobia.htm.
• Anon. Biotechnology: Plantlinguistic: – “Plants Communicate With Each Other.” http://bioinformations4all.blogspot.com/2009/08/plantlinguistic-plants-communicate-with.html.
• Jacob, Tim. 2001. “The science and myths of smell.” EMBO Reports 2 (10): 880. http://www.nature.com/embor/journal/v2/n10/full/embor301.html.
• Johnson, Steven D, Priscilla M Burgoyne, Lawrence D Harder, Stefan Dötterl, and Proc R Soc. 2011. “Mammal pollinators lured by the scent of a parasitic plant Subject collections Mammal pollinators lured by the scent of a parasitic plant.” Society 278 (January): 2303-10. doi:10.1098/rspb.2010.2175. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3119003&tool=pmcentrez&rendertype=abstract.
• Montréal, Jardin botanique de. 2012. “Chatting with a plant’s best friend – Science +” (June 3). http://www.aucoeurdelarbre.ca/en/thematics-texts/thematics-texts-details.php?id=8.
• Murray, Jeremy D. 2011. “Invasion by invitation: rhizobial infection in legumes.” Molecular plantmicrobe interactions MPMI 24 (6): 631-639. http://www.ncbi.nlm.nih.gov/pubmed/21542766.
• Shah, Jyoti. 2009. “Plants under attack: systemic signals in defence.” Current Opinion in Plant Biology 12 (4): 459-464. http://www.ncbi.nlm.nih.gov/pubmed/19608451.
• Sir Patrick Geddes, and Sir Patrick Geddes. 1920. The life and work of Sir Jagadis C. Bose. Longmans, Green. http://books.google.com/books?id=EPtCAAAAIAAJ&pg=PA97&q=”continuous”#v=twopage.
• Sugiyama, Akifumi, Nobukazu Shitan, and Kazufumi Yazaki. 2007. “Involvement of a soybean ATP-binding cassette-type transporter in the secretion of genistein, a signal flavonoid in legume-Rhizobium symbiosis.” Plant physiology 144 (4) (August): 2000-8. doi:10.1104/pp.107.096727. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1949875&tool=pmcentrez&rendertype=abstract.
• Vadassery, Jyothilakshmi, and Ralf Oelmüller. 2009. “Calcium signaling in pathogenic and beneficial plant microbe interactions: what can we learn from the interaction between Piriformospora indica and Arabidopsis thaliana.” Plant signaling & behavior 4 (11) (November): 1024-7. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2819509&tool=pmcentrez&rendertype=abstract.

To chemically identify substances, scientists around the world are trying to develop artificial taste sensors that mimic the human tongue. Recently researchers at the University of Texas in Austin have developed an electronic sensor that has the potential to detect taste as well as to identify the chemicals of any substances.1 It has uses for food and beverage development as well as medical applications.

Besides the tongue, an electronic nose has also recently been developed to mimic the sense of smell, but it can only detect volatile molecules in the air. Since many chemicals of interest, such as those in food and beverages, are not easily transported into vapor phase, there needs to be a way of detecting a combination of them in solution, such as the electronic tongue.

A team of engineers and chemists in Austin has come up with a prototype of the artificial tongue which resembles the mammalian tongue in some ways. The surface of the human tongue contains cavities which hold chemical receptors known as taste buds. The artificial tongue consists of an array of tiny chemical sensors on a square-centimeter chip. The sensors are actually polymer microbeads placed inside micromachined wells on a silicon wafer which mimics real taste buds on a human tongue. Each bead responds to specific conditions (for example, high acidity or charged ions). A special camera records those colors, which the researchers can then monitor on a computer.

One obvious application of the electronic tongue is in the rapid testing of new foods and beverages; the results could be quickly compared with databases of known popular consumer tastes. When developed further, the electronic tongue should be able to analyze chemical processing streams, biological fluids and other complex mixtures without exposing human beings to possibly harmful substances such as antigens, toxins, and bacteria. For the tasting of ice cream, though, we will likely continue to use our own tongues.

FOOTNOTES

• J.J. Lavigne, S. Savoy, M.B. Clevenger, J.E. Ritchic, B. McDoniel, S.J. Yoo, E.V.
• Ansyln, J. T. McDevitt, J. B. Shear and D. Neikirk, J. Am. Chem. Soc., 1998, 120, 6429-6430.
• See also R. Dagani, Chem. & Eng. News, June 29, 1998, 12.