PSYC 477 Neural Regulation of Sleep + Narcolepsy

old sleep regulation hypothesis

sleep is result of decreased brain activity induced by fatigue

sleep reg hypothesis 2

wakefulness maintained by tonic activity of reticular formation driven by sensory input

sleep reg hypothesis 3

anterior reticular formation promotes wake

posterior RF inhibits anterior RF and produces sleep

sleep reg hypothesis 4

sleep actively induced and highly organized brain state

issue with sleep reg hypothesis 1 (old)

sensory stimulation not enough to keep you awake

lesion to RF but intact sensory systems = permanent sleep-like state

issue with sleep reg hypothesis 2

transection to RF leads to decreased sleep

issue with sleep reg hypothesis 3

sleep is not on/off state

sleep is not just a period of reduced activity

lesion to circadian clock results in…

sleep rebound after sleep deprivation

encephale isole

isolated brain

cut between medulla and spinal cord

eeg alternates sleep-like and wake-like activity

cerveau isole

isolated forebrain

cut between hindbrain and forebrain

constant sws on eeg

reticular activating system

produces wakefulness

electrical stimulation wakes up cortex

inhibited by medulla

raphe

serotonin

high during wake

locus coeruleus

norepinephrine

high during wake

tuberomammillary nucleus

histaminergic cells

wake

dorsolateral hypothalamus

hypocretin (orexin)

promotes arousal

basal forebrain is most active during what stage of sleep?

SWS

gabaergic neurons

inhibitory NT

inhibits histamine cells

produces SWS

ventrolateral preoptic area

promotes sleep

releases gaba

c-Fos

people who died from encephalitis and had a) had lesions in b)

a) hypersomnia

b) tuberomammillary area

people who died from encephalitis and had a) had lesions in b)

a) insomnia

b) ventrolateral preoptic area

what is REM regulated by?

midbrain and pontine nuclei

REM-on cells

cholinergic activity

acetylcholine

REM-off cells

serotonin cells in raphe

norepinephrine in locus coeruleus

histaminergic cells

what is cataplexy

loss of muscle tone during waking

regain consciousness but not muscle tone

sleep paralysis

which chemicals influence sleep

prostaglandin d2

adenosine (builds up during wake)

melatonin

growth hormone

interleukin

what do the RPO and RPC do

induce REM when stimulated but eliminate REM if lesioned

what do the RPO and medial medulla do

inhibits muscle tone (atonia)

prostaglandin d2

induces sleep

ventricles

produced by support structures

acts on DP1 receptor

increased levels during sleep deprivation

receptors in arachnoid membrane

adenosine

adenosine antagonists (caffeine) promote wake

adenosine agonists induce sleep

increase in basal forebrain and cortex with sleep deprivation

what do adenosine agonists do?

activate VLPO

turn off TMN

where does melatonin come from

pineal gland

when is melatonin released

released at night

inhibited by light

where/when is growth hormone released from

anterior pituitary during NREM sleep

what regulates growth hormone

hypothalamus

interleukins

muramyl peptide

induce SWS

what is narcolepsy

irresistible, recurring, short sleep episodes

symptoms of narcolepsy

daytime sleepiness

cataplexy

sleep paralysis

hypnagogic hallucinations (while falling asleep)

what can cause cataplexy in narcoleptics

intense emotion