The Blind Mole Rat, Research Paper Example

The blind mole rat cannot see but needs light for other reasons.  While flashes of light produce no response in terms of visual evoked potentials, exposure to light does lead to specific responses in terms of their circadian related activity levels and their thermoregulatory capacity. It is thought that visual acuity in response to light developed later in terms of evolution than other types of physiological responses in particular those that have to do with circadian rhythms.

In order to reset your circadian rhythm when traveling across time zones you can use melatonin. When traveling across time zones east to west, taking melatonin before the time you will go to sleep when you are at your destination will help you begin to fall asleep earlier before you arrive. Combining melatonin at the new bedtime, going to sleep and waking based on the time schedule you will be on at your destination and exposure to sunlight as soon as you get up at home can help you to reset your inner clock and avoid jet lag.  If you have enough time, gradually resetting your circadian rhythm based clock by shifting your sleep time back a half hour a night combined with melatonin before sleep and early morning sun is the best option.  If you have only a few days then shifting it more suddenly can help somewhat.  When traveling west across time zones melatonin is not usually helpful since it makes you sleepy so it cannot be used to help you stay awake longer and get up later for a westward shift in circadian rhythm.

PGO burst cells increase firing before and during REM sleep in cats. The signals from these neurons also are linked to other sleep characteristics including the directionality of eye movements, and increased cortical activity during REM sleep. When cats are deprived of REM sleep, there is a certain duration of REM rebound afterwards. However, it has been determined that this rebound is not due to the deprivation of REM sleep specifically, but is actually due to phasic event or PGO waves.  This means that there will be a naturally limited amount that can occur due to there being negative effects of cortical activity that is excessive. Thus, given the natural limitation placed on the amount of cortical activity that can occur without detrimental effects on memory consolidation and other functions, and that REM sleep in cats is characterized and triggered by PGO waves there will be a point at which no additional REM rebound can occur. This occurs around the 25 day mark after continued REM deprivation.

It is more difficult to deprive someone of NREM sleep because we spend far more time in this type of sleep than in REM sleep.  Approximately 75% of the time we spend sleeping is spent in NREM sleep.  So to deprive someone of NREM sleep would be difficult to do on a practical level.  It would mean keeping the person awake for the majority of the night.  In addition, it is almost impossible if not completely impossible to go from wakefulness to REM sleep.  In order to completely deprive someone of NREM sleep this would be required.  Additionally as there are 4 different stages of NREM sleep, each of these four would have to be identified so the person could be woken over each of them. Going from wakefulness to sleep and deeper sleep means that going from being totally awake to being in REM sleep necessitates at least one cycle of NREM sleep lasting approximately 90 minutes. Normally, the ability to go into REM sleep is dependent on going through at least on cycle of REM sleep.  Also, after REM sleep there must be a transition to NREM sleep for a refractory period during which REM sleep cannot occur.  So to deprive someone of NREM sleep means to also be forced to deprive them of REM sleep.