Groundhog hibernation is a truly amazing thing.During the summer a groundhog's heart rate is around 80 beats a minute, and it has a temperature of 98 degrees Fahrenheit.
In the coldest parts of winter, however, a groundhog's heartbeat drops to only 5 beats a minute, and its body temperature drops to just 38 degrees.
Groundhog mortality in winter is very high (mostly due to congestion and influenza), but the amazing thing is that they can live at all with such a low heart beat. How do hibernating animals do it? Scientists are still studying that question, in part to figure out how stroke victims might be kept alive.
One answer seems to be that hibernating ground squirrels, such as marmots, shut off their brain's ability to make proteins.
Another trick seems to have something to do with a hibernating animal's ability to store anti-oxidants such as ascorbic acid (Vitamin C) which prevents brain damage when the blood flow starts again.
A third factor seems to be some change in the blood that prevents clotting, and finally, there is the fact that hibernating animals "wake up" every few weeks in order to bring their heart rates back up to normal. This occasional boost of oxygen back into the system appears to be critical, and is common to bears, groundhogs, arctic ground squirrels and a wide array of other hibernating animals.
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Reversible hibernation
Successful experiment with mice
A group of researchers of the Fred Hutchinson Cancer Research Center in Seattle was able to hibernate of mice and then rianimarli immediately after the experiment. The discovery, explain the experts, is nothing short of extraordinary. Hibernate a patient at the end of life, for example, could allow doctors to keep it stable, however, until it is able to intervene in an appropriate manner. Scientists in the research were able to achieve the ambitious goal by entering the mice in a room areata with high concentrations of hydrogen sulfide (H2S), which, naturally, is to adjust the temperature and body metabolism.
After a few minutes, the experts explained, the mice died in an apparent state of unconsciousness. Respiration declined drastically by taking 120 to fewer than 10 breaths per minute and temperature, which usually is around 37 degrees, it was lowered to 11 degrees. In short, the main vital functions of the mice were suspended as, slowing down to levels hitherto unimaginable.
The experiment aimed to sleep but not the guinea pigs but to find out how the same could be awakened. Scientists there have succeeded, and without consequences for the poor mice after 6 hours and using the normal fresh air. Currently doctors use a process of hibernation is very similar to the one discovered by scientists of the Fred Hutchinson Cancer Research Center, but unlike the latter, the patient must be awakened within 1 hour from freezing. Otherwise we risk produce irreversible damage to the brain.
The discovery, according to comments released by some experts, could prove very useful for patients suffering from sleep tumors and can thus subject to massive doses of radiation. There is also those who see in this discovery the key that will open the doors of space exploration. The astronauts, in fact, may be hibernated not just left the Earth and awakened even years later, perhaps before entering into a distant planet.
Link:
>>> Fred Hutchinson Cancer Research Center (http://www.fhcrc.org/)
Source: GiornaleTecnologico (http://www.giornaletecnologico.it/scienza/200504/26/4269070705bc6/)
IBERNAZIONE: Towards suspended animation.
Pets not ibernanti put into hibernation with hydrogen sulphide.
http://www.betterhumans.com/Program_Files/Betterhumans/Images/Contex/2004-10-20-1.jpg (http://www.betterhumans.com/Program_Files/Betterhumans/Images/Contex/2004-10- 20-1.jpg) The hydrogen sulphide and 'a particularly toxic gas, but' also produced by mammals, in small doses, to regulate body temperature. It performs this function by reducing the quantity 'of oxygen in the cells used to produce energy. With great surprise, researchers from the Fred Hutchinson Cancer Research Center in Seattle noted that only a few minutes dall'inalazione gas, the laboratory mice appeared to faint and then enter a mini-hibernation six hours. The temperature fell from 37 to 15 degrees and breathing rate from 120 to 10 per minute. It 'been calculated that the metabolism will slow down by 90%, reaching a level of activity' phone least drastically reduces the need for oxygen. Some breath of fresh air and 'sufficient to restart the mice that did not then demonstrated behavior or functionality' abnormal. According to Mark Roth (http://myprofile.cos.com/mroth), the leader of the team, the hydrogen sulphide "reveals a flexibility 'metabolic you do not know that there [...] We think this is Capacity of a 'latent all mammals. " Potential applications include emergency treatment of victims of stroke, heart attack and bleeding (to limit the damage from lack of oxygen to the brain and heart), as well as' to "gain time" on who is awaiting an organ for transplant. If similar results are found in larger animals, Roth speculation that could lead to clinical trials within five years.
Roth Lab Home Page (http://www.fhcrc.org/labs/roth/) at the Fred Hutchinson Cancer Research Center in Seattle
Gas Puts Mice on Pause (http://www.betterhumans.com/News/news.aspx?articleID=2005-04-21-2) - inducing hibernation in non-Hibernating mammals, technique could be used to "buy time patients "(BetterHumans)
Source: Estropico (http://estropico.blogspot.com/2005/04/23-aprile-2005-ibernazione-verso.html)___________________________________Physiology of Meditation
The state of meditation that is achieved by practicing yoga and other Eastern mystics is accompanied by physiological changes?
A study conducted on volunteers in the United States gave an affirmative answer Robert Keith Wallace and Herbert Benson *
How does the human body can adapt to changes harmful environmental psychologically? The era of technology is putting to the test this ability more than it has ever been done in the past. The effect of rapid change - unprecedented in scale, complexity and novelty - that technology is creating in our world seems to be detrimental to the mental and physical health of modern man. Some of the common disorders of our time, especially "the gastric neurosis" and high blood pressure can be partly attributed to the climate of uncertainty that characterizes our environment and daily life. Since it is unlikely that the environment will develop in a less complex and more predictable, the only thing to do is to continue research on resources that the human body has to deal with what is happening in the environment.
There are many ways intact by which an individual can control his physiological reactions in the face of psychological events. Among these, the most important for this control come from some eastern meditation practices: yoga and Zen Buddhism.
For a long time in India it is believed that those who practice yoga are able to provide services outside the norm, as voluntary cessation of the heartbeat or survive for long periods in a very narrow, closed, airtight, or very intense cold without food or with the body in a position contorta. One of the first researchers who studied these facts in an objective was the cardiology French Thérèse Brosse, who went to India in 1935 carrying a portable electrocardiographs so you can record the heart of some players. La Brosse concluded from its tests, that one of the subjects discussed was really able to stop his heart. In 1957 two American physiologists, M. A. Wenger of the University of California at Los Angeles and B. K. Bagchi of the Faculty of Medicine of the University of Michigan, conducted a more extensive research in collaboration with B. K. Anand of All-India Institute of Medical Sciences in New Delhi. None of practicing yoga taken by them in observation equipment with much more elaborate than those used by Brosse, showed you can stop your heart. Wenger and Bagchi concluded that the disappearance of the signal of cardiac nell'elettrocardiogramma of Brosse was probably an artifact, because the cardiac impulse can sometimes be covered by electrical signals due to a contraction of the muscles of the chest. (In an effort to stop the heart, yoga practitioners usually make the so-called Valsalva maneuver that increases the pressure intratoracica and can be performed holding its breath and bowing down with effort). Wenger, Bagchi and Anand found that some practicing yoga could either slow down the speed of the heartbeat that the respirator.
The reports of numerous other studies conducted in the years 1959 and 1960 show that meditation, as practiced in yoga or Zen, could produce a variety of physiological effects. One effect was shown to reduce the speed of metabolism. Looking in, Japan, the Zen monks who had many years of experience in the practice of deep meditation, Y. SUGI and K. Akutsu found that during meditation, in these subjects oxygen consumption decreased by around 20% and decreased the production of carbon dioxide. These signs naturally feel a slowdown of metabolism. A New. Delhi, Anand and his two collaborators, G. S. Chhina and Baldeu Singh, made a similar discovery by examining a yoga practitioner, locked in a metal box sealed, the subject substantially reduced its consumption of oxygen and removing carbon dioxide.
These tests showed that meditation has its effects through a mechanism of control "involuntary" of the body, probably the autonomic nervous system. The reduction of the elimination of carbon dioxide could have been explained clearly as a voluntary subject - slowdown in breathing - but that action should not significantly affect the intake of oxygen by the body tissues. Consequently it was reasonable to assume that the fall in the consumption of oxygen, which reflects a decrease in need of oxygen inhaled, it must be due to changes of a process that is not subject to manipulation in the sense current. Research with electroencephalographs show that mediation because of changes in brain power. In Studies in Zen monks, A. Kasamatsu and T. Hiraj of the University of Tokyo found that during meditation to socchiusi eyes, the monks developed predominantly alpha waves - waves that ordinarily dominate when a person is completely relaxed with eyes closed. During the monks in meditation alpha waves increased in size and regularity, particularly in the frontal and central regions of the brain. In subjects who had more experience of meditation other changes occurred: alpha waves decreased from a normal frequency of 9-12 cycles per second at 7-8 cycles per second and appeared ritmicheteta waves with a frequency of 6-7 cycles per second . In India, Anand and other researchers found that even in practicing yoga as in Zen monks noted an increase of alpha during meditation. N. N. Das and H. Gastaut, in electroencephalographs examinations of seven practicing yoga, observed that as the advanced meditation alpha waves cedevano way to a quick wave activity with a speed of 40-45 cycles per second and these waves in turn diminished ec'era a return to alpha waves and TETA.
Another physiological response analyzed by the researchers was the first skin resistance to an electric current. It is believed that this measure reflects the level of "anxiety" while a decrease in skin resistance is increased anxiety, increased a greater relaxation. The result is that meditation increases the resistance in practicing yoga and somehow stabilizes the resistance in Zen meditators.
We decided to undertake a systematic study on the physiological effects, or rather on links physiological meditation. In the study of literature, we found a disconcerting change in the circumstances and results of different studies. The subjects differed much to the techniques of meditation, for their experience and their performance. This is less true of Zen practitioners, as everyone uses the same technique, but it is characteristic of yoga practice that has many more devotees. The state called yoga (which means' union ') has a generally accepted definition: a state of consciousness "superior" reached with the body to rest completely relaxed and the mind with alarm at the highest level and relaxed. However, in an attempt to reach this state, Indian students use different ways. Some are trying to achieve this through a strenuous exercise, others focus on the control of a well-defined, such as breathing rate, others focus exclusively on mental processes, based on some gimmicks for concentration and contemplation. The difference of techniques can produce a dichotomy of physiological events, peresempio, while those that use the contemplation of which showed a decrease in oxygen consumption, in order to reach those who practice yoga physical exercises there is an increase in the consumption of oxygen. Moreover, since most of the technical discipline requires a long and rigorous training, the scope of capacity is large and it is difficult to recognize who is an 'expert' and experienced as he can be. All these complications made it extremely difficult course, the problem of choosing the subjects fit for our systematic study.
Fortunately there is a widely practiced yoga technique that is standardized so well that we can conduct studies on a large scale in terms reasonably uniform. This technique, known as "transcendental meditation", was introduced by Maharishi Mahesh Yogi and is taught by an instructor who trained him in person. The technique does not require intense concentration or specific forms of strict control fisicoè mental and easily so you learn all those who have undergone a period of even relatively short training are "experts". The workout does not mean faith in beliefs or ways of life details. It consists simply of two sessions a day of practice, every 15-20 minutes.
The practitioner sits in comfortable position with eyes closed. Through a systematic method that was taught he perceives a sound or a thought "suitable". Without groped to focus specifically on this, lets his mind freely and experience with his thinking, as students themselves report, rises to "a more beautiful and more creative in a simple and natural." It is believed that the United States more than 90 000 men women were instructed in transcendental meditation by that name. Then we had available peri our studies a large number of subjects taught in the same way.
What follows is a detailed report on findings made on a group of 36 players. Some have been found at Thorndike Memorial Laboratory, a section dell'Harvard Unit of Medical City Hospital in Boston. The others were kept under observation at the University of California at Irvine. 28 were male and 8 women, an age which had ranged from 17 to 41 years. Their experience in the field of meditation ranged from less than one month to nine years, but the majority had experience from two to three years.
During the test each subject served as control of himself, passed as part of sitting in meditation and so was not normal meditative. AI subject devices were used to continuously record blood pressure, heart rhythm, the rectal temperature, skin resistance and events electroencephalographs and during this period were taken samples at intervals of 10 minutes to analyze the consumption of oxygen, the elimination of carbon dioxide and other parameters. The subject sat on a chair. After an adjustment period beginning 30 minutes had the analysis and continued for three periods: 20-30 minutes of quiet was premeditated, then 20-30 minutes of meditation, and then 20-30 minutes when the subject was requested to suspend the meditation.
The measures of oxygen consumption and the disposal of carbon dioxide confirmed exactly what had been reported in previous work. The oxygen consumption decreased sharply from 251 cubic centimeters per minute during the pre-meditation, to 211 cubic centimeters during meditation, during the post-meditation gradually increased again to 242 cubic centimeters. Similarly, the removal of carbon dioxide decreased from 219 cubic centimeters per minute in the period preceding the start of meditation to 187 cubic centimeters during meditative to return to normal during the post-meditation. The ratio of removal of carbon dioxide and oxygen consumption (in volume) remained essentially unchanged during the three periods, which says that for both the control factor was the speed of metabolism. The reduction in metabolic rate (and thus the need for oxygen) during meditation was mirrored in a decline, almost involuntarily, the speed of respiration (two fewer breaths per minute) and the volume of atmosphere (one liter less per minute).
To measure blood pressure and take samples of blood, we used a catheter inserted into the brachial hiding his arm at the sight of the subject with a curtain so as not to expose it to possible psychological trauma caused by the sight of blood taken. Since it was engaging the local anesthetic at the point where the catheter was inserted, the subject does not felt any sense when you take the blood. The blood pressure was measured continuously by means of a device connected to the catheter.
We found that the blood pressure of subjects is maintained at a level low enough for the duration of; down at this level during the period of calm before the meditation and not changed significantly during and after the period of meditation. The average systolic pressure was equal to 106 mm of mercury, diastolic blood pressure at 57 and the average to 75. In arterial blood, the partial pressure of carbon dioxide and oxygen remained essentially unchanged during meditation. There was a slight increase in blood, indicating a slight metabolic acidosis during meditation, but the acidity falls within normal variation.
Measures of concentration in the blood lactate (as an index of anaerobic metabolism, and metabolism in the absence of free oxygen) showed that during meditation the level of lactate fell precipitately in subjects. During the first 10 minutes of meditation on the level of arterial blood lactate decreased at a speed of 10.26 milligrams per 100 cubic centimeters per hour, nearly four times faster than the rate of decline in people in normal condition of rest or supine in the same subjects during pre-meditation. After the players stayed meditation lactate levels continued to decline for a few minutes and then began to rise, but at the end of the period of post-meditation, it was still considerably lower than the level it had in the period before the meditation. The average level during the pre-meditation was 11.4 milligrams per 100 cubic centimeters, during meditation than 8 milligrams and during the period after the meditation of 7.3 milligrams.
How can we explain the fact that the production of lactate, which is an index of anaerobic metabolism, is so strongly reduced during meditation? New experiments provided a possible answer. These experiments were the speed of blood flow in patients in meditation, and the explanation that we can draw is important when taking into account the psychological benefits that can be achieved by meditation.
In studies conducted at the University of Tubingen, H. Rieckert reported that during the transcendental meditation in his subjects observed an increase of 300 percent in the blood stream dell'avambraccio. In similar measures made on our players have found an increased blood flow dell'avambraccio much less: 32%. Nevertheless this increase was interesting and offered an explanation to the relatively large decline of the concentration of lactate in the blood. The primary site for production of lactate in the body is skeletal muscle tissue. Probably, the observed acceleration of blood flow in the muscles dell'avambraccio, accelerates the injection of oxygen to the muscles. The increase of oxidative metabolism resulting may replace the anaerobic metabolism, and this would explain the sharp decline in production of lactate accompanying meditation.
The interesting result of this interpretation is that this gives the greatest prominence to the autonomic nervous system. In a situation of constant blood pressure (which is what occurs during meditation) the speed of blood flow is controlled primarily by expansion or constriction of blood vessels. The autonomic nervous system in turn controls the behavior of blood vessels. In this system a component, a network of sympathetic nervous sometimes results in the secretion of acetylcholine through special fibers and therefore stimulates the dilation of blood vessels. In contrast, most of the sympathetic nervous system stimulates the secretion of noreprinefrina causing the constriction of blood vessels. The data Rieckert about a sharp increase blood flow during meditation suggest that meditation increased activity of the sympathetic nerve substance secerne that dilatante. Our results for a much more modest increase blood flow showed a different interpretation: namely that meditation reduces the activity of most of the sympathetic nervous so that the constriction of vessels due to it is lost. This interpretation can explain the sharp decline in production of lactate during meditation, it is known that norepinephrine stimulates the production of lactate and therefore it is anticipated that a reduction in the secretion of norepinephrine, through the inhibition of most network friendly , Decrease the production of lactate.
Whatever the explanation for the decreased levels of blood lactate, it is clear that this has a psychological effect. In patients suffering from neurosis anxious there has been a sharp increase of lactate in the blood when placed under stress.
Pitts and J. N. McClure jr., A member of Pitts at the Faculty of Medicine of the University of Washington, have shown experimentally that an infusion of lactate could lead to attacks of anxiety in these patients and could produce symptoms of anxiety even in normal subjects. Moreover, it is significant that in patients with hypertension (essential and kidney) are observed blood lactate levels higher in a state of rest compared to patients who are not suffering from hypertension, while the low level of lactate in practicing meditation transcendental is associated with low blood pressure. All in all, it is reasonable to hypothesize that the low level of lactate found in patients during and after the transcendental meditation has been responsible for the relaxation of meditators
Other tests conducted on practicing meditation confirmed the framework of a state of deep relaxation in full consciousness. During meditation resistance of the skin increased significantly under the stimulus of an electric current, in some cases the increase was more than four times. The heart rate slowed down by an average of three beats per minute. Elettroencefalografiche recordings revealed a significant intensification of alpha waves in all subjects. The waves were recorded on tape by seven main areas of the brain and their performance analyzed with a computer. Usually there was an increase in alpha wave lens 8-9 cycles per second in the frontal and central regions of the brain during meditation. In many subjects this variation is also accompanied by waves TETA evident in the frontal region.
To sum up, our players during the practice of transcendental meditation expressing those physiological signs that we describe as a state ipometabolico conscious': reducing the consumption of oxygen, the elimination of carbon dioxide and the pace and volume of breathing, a slight increase in arterial blood, a significant decrease in the level of blood lactate, a slowing of the heartbeat, a significant increase in skin resistance, and a path elettroencetalografico with intensifying slow alpha waves and waves of activities occasional TETA. These physiological changes in people who practiced the technique of transcendental meditation, easy to learn, were very similar to those that have been observed in yoga experts trained and very Zen monks who have experience in the field of meditation 15-20 years.
How can you compare the physiological changes that appear when meditazione with those that are observed in other conditions such as the relaxation of sleep el'ipnosi? There is little resemblance. While the consumption of oxygen decreases rapidly within the first five or ten minutes of transcendental meditation, hypnosis does not cause some variation of this major metabolic index, and sleep during the consumption of oxygen decreases in any significant way only after several hours. During sleep the concentration of carbon dioxide in the blood increases significantly, which is to indicate a reduction in breathing. There is a slight increase in blood, and this is clearly due to the decrease of ventilation and not to a change in metabolism as happens during meditation. The engineer skin resistance increases during sleep, but the speed and extent of this increase is much smaller than those occurring during the transcendental meditation. Paths electroencephalographs characteristic of sleep are different, they consist predominantly of high voltage (strong) in order to slow from 12-14 cycles per second and a set of weaker waves at various frequencies - a framework that is not found during transcendental meditation. Paths that are observed during hypnosis not have any connection with those of the state of meditation, a person hypnotized in the activity of brain waves take the shape of the mental state that was suggested to the subject. The same goes for changes in heart rate, blood pressure, respiration and skin resistance, a person hypnotized by the magician in all these parameters reflect the state suggested.
It is interesting to compare the effects achieved with the meditation by those who can establish through a conditioning effect. Through such conditioning, animals and people have been trained to increase or decrease their heart rate, blood pressure, the formation of urine, and other autonomous functions. Through the use of rewards that act as an incentive, the subject is taught to respond to specific internal impetus some. This process and the results are quite different from what happens in transcendental meditation. While the packaging is limited to produce specific responses and depends on a stimulus and control operated by an incentive, meditation is independent of these factors and not produce a single specific answer, but a set of answers that mark a state of deep relaxation .
The picture changes suggests that meditation causes an integrated response or reflex, which is mediated by central nervous system. A well-known reflection of this nature was described several years ago by the famous Harvard physiologist Walter B. Cannon, this is called 'reaction to fight or flight' or 'defensive alarm. " The sympathetic nervous system stimulated puts into motion a series of logical answers not marked by increases in blood pressure, heart rate, blood flow in the muscles and oxygen consumption. The state ipometabolico produced by meditation is obviously opposite to that in almost all aspects. It seems much like the opposite of the reaction of fight or flight.
During the prehistory of man is likely to alarm defensive reaction has been a tremendous value for survival and that it is rooted in its genetic. This reaction continues to be evoked in all its aspects interior when the individual feels threatened. Yet in our time of the reaction is often anachronistic. Although the alarm defensive reaction is not generally appropriate, the answer is interior with remarkable frequency evoked by the rapid and unsettling changes that threaten modern society. There are good reasons to believe that the constant stimuli of changing the sympathetic nervous system are largely responsible for the high incidence of hypertension and other serious diseases like that are common in our society.
In this circumstance the state ipometabolico, which represents the state of rest, rather than the hyperactivity of the sympathetic nervous system, can give directions to improve the state of health. It would be very helpful to seek the possibility of clinical application of this state of rest and relaxation conscious.
(*) An article published in the No 45, May 1972 of the magazine "Science"
Mirko
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