Sleep Deprivation: Physiological Psychology, by Zaheer Kazi http://www.pitzer.edu/~zkazi/sleepdep.html Sleep deprivation is required for most college students and most humans at some point in their lives. There have been many attempts to overcome sleep-dep using various stimuli, usually in an attempt to "wake someone back up", drugs, which are most often but not always amphetamines, and sleep(microsleep as opposed to a full nights rest). This paper will start with some of the physiology behind sleep and continue with how that is affected by the various methods of overcoming sleepiness and its affects. Very little is known about the exact mechanisms involved, what we do are generalities about which chemicals are where and what happens when they are absent or what sleep deprivation does to their levels. The conclusion will have my recommendations based on the research used for this paper and on my personal experiences of teenage wandering. The parts of the brain most associated with the processes of sleep are the thalamus, the medulla oblongata, and between them, the pons. Another important formation is the suprachiasmatic nuclei. This is in the hypothalamus, dorsal to the optic chiasm. The two main neurotransmitters are serotonin and norepinephrine. Melotonin also has a regulatory effect which will be covered below. There are four main neuron clusters which regulate sleep. One is the reticular formation, which is within the pons and upper brain stem. Norepinepherine from the locus coerulosus is activated here and causes arousal. The locus coerulosus is in the pons and is where noerpinepherine is found. The raphe nuclei, which is just caudal to the locus coerulosus produces serotonin. Serotonin induces sleep by inhibiting the reticular formation. A study done on djurgarian hamsters revealed an increased rate of serotonin turnover caused by sleep deprivation. The fourth cluster is the suprachiasmatic nuclei. This regulates the timing (not the duration) of sleep. Melotonin is the chemical at work here. In a study of prolonged sleep deprivation, four symptoms seemed most prominent. They are a deep negative energy balance and the symptoms of malnutrition that go with it, heterogeneous decrease in certain cerebral functions, low thyroid hormone concentration and suppression of the immune system. These symptoms are those which other symptoms can be associated with. The cause of the low thyroid hormone concentration I could not find, but this is probably related to the negative energy balance. Thyroid hormone regulates metabolism. A lot more energy is expended in this state than is actually being metabolized, resulting in a severe negative energy balance. Another result of this is also a decreased body temperature. The decreased resistance to infection can also be related to the metabolic problems. The first system to start losing resources is the immune system. In severe cases the immune system will be cut off to the point of not even showing symptoms while fighting infection. Humans rarely reach a stage where this becomes life threatening, with the exception of speed freaks. The heterogeneous decrease in cerebral function is quite straight forward. Mostly the thalamic and limbic systems are affected as is cognitive ability. Oddly, the medulla is not affected, as far as we know anyway. There are four common methods of overcoming sleep deprivation (outside of actually going to sleep for a full rest). The most commonly studied method is drug use. Another method, more often used for long term readjustment of ones schedule was light exposure. The purpose here was to readjust circadian rhythms. A strong sensory stimulant is often used in order to jolt a person into waking up, while it does work, its effects are short lived once the stimulus is gone. The most effective such stimulus is a physical threat or perceived physical threat. The last method involves actually going to sleep, but not for as long as one normally would. This is refereed to a microsleep or prophylactic naps. There are many studies of caffeine’s effect on sleep deprivation symptoms. As an amphetamine it increases metabolism, reversing the effects brought on by the deficiency in thyroid hormones. This does not do anything for the cerebral functions or restore cognitive ability, though it does aid in awareness. None of these studies examined more than 48 hours of wakefulness. Dexedrine was in a study by the US army on helicopter pilots. The drug almost completely negated the side effect for up to 34 hours. The test was not done for more than that time, as the shift for a pilot is then over. It should be noted here that the pilots were doing what they had been trained to do, and were in an exiting situation which was keeping them awake. No learning abilities, as would be needed for studying, were measured. There has been a study where 60 hours of sleep-dep were dealt with successfully using monafidil, but this is a new drug and as of my inquires, was not commonly available in the US. Light has been used to counter the effects of a night shift for diurnal workers. This was compared to using melotonin for the same effect. Melotonin was only marginally more effective than the placebo. Nocturnal people can gain similar benefits for a daytime schedule by using darkness in a similar manner. Microsleep is effective during long periods of wakefulness, though it should be done carefully. Resting with your eyes open can be effective, or napping where you don't actually fall asleep, for half an hour or so. This is highly individual, and should thus be experimented with individually. As was mentioned before, symptoms of malnutrition appear early in sleep deprivation. This can be significantly offset by eating well. Remember that the efficiency of your metabolism is much lower than it normally is, so don't be afraid to eat a lot if you feel like it. It may seem to be easier to stay awake when your cold. Don't let that happen. With your metabolism already not in a good state its very easy for the bodies temperature to fall to hypothermia levels. When outside, warmth can easily be brought by wearing tights with jeans or tight shorts. The important part here is to double layer your clothing. In doors, this should not be as much of a problem. Another complication to watch out for is the suppression of the immune system. When the bodies resources are being cut down, the immune system is the first to go. As mentioned before, this can get to a level where you wont even feel symptoms of infection because your body is simply too busy doing other things to fight the infection. Its likely that you will sleep in time for this not to be a problem, but its just another reason to be careful while your in this state. Caffeine (or any stimulant) can only go as far as the body has resources to use. When a stimulant is used, the stimulant only increases the use of the other resources which are already there. This also causes a dependency which must be addressed as soon as the sleep deprivation period is over. The caffeine dependency is not as strong as the dependency built by more effective stimulants but should not be taken lightly. Again, this is an individual reaction.