[Relation of excitability cycles of cortical reactions to the qualities of afferent stimuli].

The excitability cycles of neurons of the rabbit visual cortex in response to the optic nerve shock were compared with those in response to small light flashes. The pairs of stimuli consisted either of conditioned shock and testing light flash or of conditioned light flash and testing shock. The inhibitory phase of the response to the nerve shock was unable to depress a powerful reaction to adequate light stimulation. However, the profound inhibition of response to the optic nerve shock was obtained at the end of the response to the preceding light stimulation.