PSYCO275 Chapter Notes - Chapter 13: Intrinsically Photosensitive Retinal Ganglion Cells, Retinohypothalamic Tract, Optic Chiasm
10 Dec 2016
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Final exam review (neural basis of the biological clock) A region of the hypothalamus, the suprachiasmatic nucleus (scn), acts as the master biological clock. If all the pathways into and out of the suprachiasmatic nucleus are cut, the scn neurons maintain their rhythmic electrical activity. The intergeniculate leaflet and the pineal gland also display clocklike activity. In the brain, scn cells connect to one to another through inhibitory gaba synapses, and these connections allow them to act in synchrony. Retinohypothalamic tract: neural route formed by axons of photosensitive retinal ganglion cells from the retina to the suprachiasmatic nucleus; allows light to entrain the rhythmic activity of the scn. Melanopsin-containing ganglion cells use glutamate as their primary neurotransmitter but also contain two cotransmitters, substance p and pituitary adenylate cyclase-activating polypeptide (pacap). The scn consists of two parts, the core and the shell. Core neurons are not rhythmic, but they entrain the shell neurons, which are rhythmic.
