PSYCO275 Lecture Notes - Lecture 13: Intrinsically Photosensitive Retinal Ganglion Cells, Slow-Wave Sleep, Retinohypothalamic Tract
25 Apr 2019
School
Department
Course
Professor
Document Summary
Inherent timing mechanism that controls or initiates biological processes. Free-running rhythm: rhythm of the body"s own devising in the absence of all external cues. Suprachiasmatic nucleus (scn): master biological clock located in the hypothalamus. If no scn, circadian rhythm won"t be linked to light-dark, but it will be synchronized ot other environmental stimuli. Scn receives light info through the retinohypothalamic tract. Retinohypothalamic tract: neural route formed by axons of photosensitive retinal ganglion cells from the retina to scn. Allows light to entrain (reset) the scn"s rhythmic activity. Anterior hypothalamus: promotes sleep (if damaged, trouble sleeping) Posterior hypothalamus: promotes wakefulness (if damaged, sleep continuously) Cerveau isole: if you sever between the inferior and superior colliculi, eeg shows continuous slow wave sleep. Encephale isole: if you disconnect the brain and spinal cord, no disruption of eeg. Use 3 electrical body signals: brain activity (eeg), muscle activity (emg) and eye movement (eog) Waking state: small, high frequency waves (beta waves)
