From Wake To Slow Wave Sleep

Question 1

Possible proximal causes of sleep

Answer 1

• being awake exhausts a supply (when it’s gone we sleep)
• being awake leads to build up of toxins (when they teach critical, we sleep)
• circadian rhythms (when it’s time- we sleep)
• explanations aren’t mutually exclusive

Question 2

Assumptions & ethics

Answer 2

Ethics- most neurotransmitter info comes from animal studies

Cross-species generalisation- conservation of function, has function been conserved (kept the same) across species?

Question 3

Where are these chemicals?

Answer 3

Circulating in blood- all over body, not just brain

All of body gets tired, builds up toxins?

Bottlenose dolphins sleep with one half of brain at time, common in water species, need to keep awake to keep swimming

If in brain then in neurones most likely

Question 4

Candidate chemical- adenosine

Answer 4

Increase in adenosine= increase in slow wave sleep

Prolonged wakefulness= increase in adenosine

Decline in adenosine= sleep

Question 5

What causes this?

Answer 5

Consequence of glycogen metabolism

Released by glial cells in brain

Support metabolism of neurons (ATP)

Involved in some way in neurotransmission

Neuromodulator changes the activity of a large number of neurons at one time

Question 6

Arousal centre 1- in basal forebrain

Answer 6

Before hypothalamus is basal forebrain (anterior to it)

Maintains arousal (wakeness)

Acetylchlorine producing neurons (chlorinergic neurons)

Also GABA neurons

Question 7

Arousal centres to the rest of the brain

Answer 7

Neurons have very long branching axons

Neurotransmitter is diffused widely

Allows whole brain modulation to occur