[Specificity of hippocampal field CA3 neuronal responses to repetitive single stimuli]

It has been shown on alert rabbits that responses of field CA3 units to stimuli eliciting (single tones) and not eliciting (single flashes) an activation reaction are substantially different. 75% of units responsive to a flash exhibited: less pronounced tonic extinctive responses, stable structurized phasic reactions and the dynamics of responses in the form of changes in their types. The system of field CA3 units "triggered" by single stimulation is under control of the sensorimotor cortical area. Modulating cortical influences enhance the revealed tendencies of responses of the examined neurones to a single photic stimulus.