16 Somatosensory Receptors

5 m very sensitive threshold about pressure best to

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Unformatted text preview: onds to skin 0.5 m) very sensitive (threshold about pressure; best to skin vibration at 200-250 Hz - Very sensitive (threshold ~0.5 modified easily generated receptor largest cutaneous inner core lamellae are m): a.p. huge receptive field - Cross-section of corpuscle: diagram located deep in dermal layers; hands hands, Schwann cells with GABAergic feet - Sensory axonaxon in center: N rapidly-adapting; responds best to skin synapses on vibration at 200-250 Hz - Inner corecorpuscle actively shapes the response lamellae (L): modified very sensitive (threshold about 0.5 m) inner core lamellae are modified Schwann cells w/ for fine texture synapses GABAergic discrimination; Schwann cells with GABAergic needed synapses on axon on axon fingerprints amplify skin vibrations corpuscle actively shapes the response needed for fine texture discrimination; fingerprints amplify skin vibrations - When sensory finger rubbed on object (~250 Hz) as terminals (~250 Hz) as finger rubbed on object surfaces surfaces depolarize = release glutamate - Communicate w/ inner lamellae cells = release GABA back to sensory terminal - Cause repolarization = locks membrane at resting potential 1 of 5 2 PSL302Y: Lecture 15, by Prof. MacKay# Wed., Oct.20, 2010 - Signal is squashed: no sustained depolarization = hence rapidly adapting - Thus corpuscle actively shapes response - Needed for fine texture discrimination - Fingerprints (ridges) amplify skin vibrations (~250 Hz) as finger rubs surfaces = activate corpuscles - To have steady...
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This note was uploaded on 03/27/2012 for the course PSL PSL300 taught by Professor Mackayfrench during the Fall '11 term at University of Toronto- Toronto.

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