Download - Sleep & Dreaming

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Page 1: Sleep & Dreaming

Sleep & DreamingWhy do we sleep?

Restorative vs Adaptive Hypotheses

effects of sleep deprivation

TED talks: why we sleep

circadian rhythms

Page 2: Sleep & Dreaming

Circadian Rhythms and the… Suprachiasmatic nucleus Entrained by zeitgebers - SCN controls timing of sleep, not sleep itself

SCN

Pineal Gland

melatonin

Retinal ganglion cells containing melanosporin respond to light

Retinohypothalmic pathway

Also regulated by on-off genesIn the SCN

Page 4: Sleep & Dreaming

REM and DreamingThe purpose of REM sleep

1. perchance to dream

2. promote neural development during childhood

3. memory consolidation

Non-REM sleep

The purpose of slow wave sleep

1. rest and restoration of the body

2. cool down the brain

3. restore cognitive function, prefrontal cortex recovery

Neuronal replay in hippocampus is highest duringnon-REM sleep

During REM, memory traces are transferred to cortexThis process may take 4-7 days to become permanent

sleep & memory

Page 5: Sleep & Dreaming

What puts us to sleep Key Concepts to know

The NT adenosine inhibits arousal in the basal forebrain

Adenosine warms cells in the preoptic area which helpsto induce sleep

Neurons in the ventrolateral preoptic nucleus inhibitactivitity of several structures in the pons

tuberomammilary nucleus, PPT/LDT, LC, raphe nucleus

Info from pons goes to the magnocellular n. (in the Medulla) to induce atonia

Page 6: Sleep & Dreaming

What wakes us up

Pathway 1: PPT/LDT stimulates structures in the ponsThese structures then send info to the cortexThis pathway also shifts EEG to the arousal state

Pathway 2: Pons structures (Locus coeruleus, raphe n., tuberomammilary n., ) and basal forebrain stimulate the cortex so it can better process input from the thalamus. The lateral hypothalamus stimulates the basal forebrain and pons structures. The LH does this by releasing the peptide orexin.

Key Concepts to know


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