Neuroanatomy of sleep

Question 1

Discuss, scientifically, what wake and sleep is.

Answer 1

Waking – low amplitude, high-frequency EEG
activity and high muscle tone

Sleep
* NREM - high amplitude, low-frequency EEG
activity and reduced muscle tone
* REM - low amplitude, high-frequency EEG
activity, muscle atonia and rapid eye
movements

Question 2

What happens if you have a lesion in the mid-collicular area?

Answer 2

An increase in sleep, disrupt the wake-promoting pathways.

Question 3

What happens if the midbrain reticular formation is stimulated?

Answer 3

Decrease sleep.

Question 4

What is the function of the median Preoptic?

Answer 4

• GABAergic sleep active neurons
• Increase activity in response to increased
  homeostatic sleep pressure

Question 5

Discuss the PGO waves.

Answer 5

Synchronized activity in pons, LGN and occipital ctx
Occur prior to REM onset and during REM period

Question 6

How does the brainstem control muscle atonia and twitches?

Answer 6

In the brainstem, the sub coeruleus nucleus stimulates both the interneuron( gabaergic) and GiV nucleus, and both release GABA and glycine onto the motor neuron.

Question 7

Where are the REM-on cells found?

Answer 7

Mesopontine tegmentum, usually cholinergic

Question 8

What are the REM-off cells?

Answer 8

LC and dorsal raphe

Question 9

Describe the orexinergic control of REM.

Answer 9

SCN and DL Hypothalamus secretes Ox onto Dorsa; Raphe and Locus Coeruleus and this suppress the REM during diurnal active phase