REM Sleep Presentation:

The average person spends 36% of their life asleep this means if you live to the ripe old age of 90 you will have spent 32 years asleep. Although the precise reasons for sleep are disputed this shows that at least on some level sleep is incredibly important.

There are 5 stages of sleep, the first 4 are known as non- rem and the last is called REM. These stages do not necessarily occur in the same order but rather cycles in a 1234235432 pattern. In this talk we will be focusing on the the REM stage. REM, Rapid Eye Movement sleep, is the period of sleeping characterised by rapid and random movement of the eye, it takes approximately 90 minutes to enter into this stage of sleep after lying down to sleep. whilst we are in REM sleep we experience 2 different things the first is that our brain activity becomes massively heightened compared to the other stages of sleep, infact polysomnograms show brainwave patterns during REM sleep are very similar to to levels that occur when we are awake, it is because of this that we hallucinate and experience vivid dreams. The second is something called sleep paralysis, as our brain activity increases our voluntary muscles loose tone resulting in near paralysis of the body. Overall REM sleep constitutes about 25% of total sleep time, and is the only portion of sleep that you will remember your dreams from. REM sleep initially will last for about 10 mins but as the night goes on can last for up an hour, typically a person will experience 4-5 episodes of REM sleep a night.

Neurophysiology:

1. Area of brain responsible for sleep is located in the Pontine Tegmnetum 2. The monoamine neurotransmitters (Serotonin, noradrenaline histamine etc.) are completely inhibited during REM sleep.3. This leads to almost total motor neuron inhibition, and so the characteristic muscle atonia. Sufferers of REM behavior disorder do not have total REM atonia, and may act out portions of their dreams as a result.4. The heart rate and breathing rate during REM is irregular, and body temperature is not well regulated. 5. Breathing centres also located in the pons.

Functions of REM sleep:

1. Functions of REM sleep are not well understood, there are a number of theories;2. Consolidation of spatial and procedural memory 3. Very important for neural development (Newborns spend 80% of their sleeping period in REM sleep) Important for building neural connections and pathways.

Effects of REM deprivation:

1. Irritability and anxiety2. More attempts to enter REM sleep3. Increased appetite4. However, has been linked to decreases in depression.

Pathology: Sleep Paralysis

1. Phenomenon where a person, upon waking, is unable to move or speak temporarily2. May also have hallucinations (most common an intruder in the room)3. Breathing will stay shallow, giving them the feeling of someone sitting on their chest4. Caused by a person waking whilst the muscle atonia remains undisrupted