COGS 17 Lecture Notes - Lecture 8: Melanopsin, Melatonin, Sleep Deprivation
14 Mar 2017
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Reticular formation = net from medulla & pons > throughout forebrain; also receives from all sensory systems. Alerts brain, stimulating thalamus and basal forebrain (and from there, cortex) via ach and glutamate. Widespread connections, including thalamus, cortex, & hippocampus - plays a role in establishing memory. Releases bursts of norepinepherine (ne) - amphetamines (ne-agonists) likewise increase alertness, activity. Especially active during new task & during vigilance (sustained attention) can also be inactive while awake. Locus coeruleus (= dark blue place ) part of reticular formation in pons, Basal forebrain (just anterior and dorsal to hypothalamus) releases ach thruout cortex for arousal & gaba to inhibit cortex. Note: excitatory nt orexin from lateral hypothalamus helps maintain arousal in above systems. Adenosine a by-product of cell metabolism, builds up thru day, released in brain, inhibits basal forebrain"s release of ach. Allows gaba connections to dominate, suppressing cortical activity, promotes sleep.
