Sleep Flashcards
What kind of rhythm is the sleep-wake cycle?
Endogenous (originate from within the system) rhythm
What happens to the sleep-wake system through the first years of life?
It gradually becomes locked to the day-night cycle which is what is called a circadian rhythm
What partly controls the circadian rhythm?
Suprachiasmatic nucleus
What is the suprachiasmatic nucleus?
A structure that contains a small group of cells in the hypothalamus just above the optic chiasm
What is unusual about the neurons in the surprachiasmatic nucleus?
They have a lot of synapses between their dendrites to synchronised their firing together
What is shown in the EEG when we are awake?
Our brains show low-amplitude brain activity?
What happens to the EEG when we fall asleep?
The EEG becomes flatter at first but gradually shows increases in amplitude and decreases in frequency
What stage of sleep is characterised by increase in amplitude and decreases in frequency?
Slow-wave sleep (SWS)
What causes the changes in slow-wave sleep?
Neurons in the brain become unresponsive to their normal inputs and gradually become synchronised with each other and you lose muscle tone as neurons controlling skeletal muscle movements are actively prohibited
In what stage are we more likely to drea?
Rapid eye movement (REM) stage
How many episodes of REM sleep do most of us have?
4-6
Why do we sleep?
- REM sleep and certain stages of SWS enable the brain to recover
- SWS is when we consolidate our memory
How do we go from one stage of the sleep to next?
Through brain-stem activating system involving various neuromodulatory transmitters in a kind of molecular chain reaction that takes us through various sleep stages, synchronisation mechanisms also enable networks to pass from one sleep state to another
What is a neuromodulatory transmitter involved in molecular chain reaction?
Adenosine
What genes produce proteins that interact together to regulate their own synthesis?
per and tim
