Field potentials in the suprachiasmatic nucleus of rat hypothalamic slice produced by optic nerve stimulation.

Spatial profile of a projection from retina to the suprachiasmatic nucleus (SCN) was studied by electrophysiological method. Stimulation of contralateral optic nerve evoked the fast positive and late large negative waves in only the ventrolateral but not the dorsolateral parts of the posterior SCN. This result, in agreement with anatomical evidence suggests that the late negative wave is due to excitatory synaptic potential in the SCN and has a role for elevating the neuronal activity in the ventrolateral part of the posterior SCN daytime.