PSYC 388 : condense ntoes on readings for lecture 5
23 Jul 2011
School
Department
Course
Professor
Document Summary
~ injected radioactive amino acid into eyes and follow tracer molecules. ~ new pathway from eye to scn = retinohypothalamic tract. ~ scn lesion = loss of circadian rhythm of hormone corticosterone, involved in circadian timing of neurosecretion. ~ remove whole scn destroyed behavioural and endocrine circadian rhythms. Scn in mammals was clock that regulated several functions with period of ~24hours. Mid 1970s well established destroying scn affected timing of various behaviours in mammals but didn"t abolish behaviours themselves = arrhythmic. Scn neurones within scn generate circadian rhythm of electrical activity high in day and low at night; neurones outside scn showed circadian rhythmcity but out of phase. Scn dissected = generates stable rhythm with period of ~ 24 hours and self-sustaining oscillator. Simple model of mammalian circadian organisation circadian clock in scn produces rhythmic output that drives circadian rhythms of activity: drinking, feed, sleep, etc.
