Responses to Light of Sensorimotor and Visual Cortex Neurons in Rabbits with a Cryptic Focus of Excitation (a defensive dominant) in the CNS

In the sensorimotor cortex of rabbits with a formed cryptic (subthreshold) focus of excitation in the CNS, the spike frequencies of neurons responding to light stimulation were significantly lower (p = 0.01) than the spike frequencies of neurons not responding to light. Similar findings were obtained in the visual cortex of intact rabbits. In this case too, the spike frequencies of neurons responding to stimulation were significantly lower (p = 0.01) than the spike frequencies of neurons not responding to light stimulation. In both intact rabbits and rabbits with a cryptic focus of excitation formed in the CNS, 36 % of neurons in the sensorimotor cortex responded to light stimuli not specific to this area. In the sensorimotor cortex of rabbits with a cryptic focus of excitation formed in the CNS, as compared with intact rabbits, there were significantly more (p = 0.01) cells responding to light stimuli with latent periods of less than 100 msec and significantly fewer (p = 0.02) responding to light stimuli with latencies of 200–300 msec. In the visual cortex of rabbits with a formed cryptic focus of excitation in the CNS, as compared with intact rabbits, significantly fewer (p = 0.01) neurons responded to light stimuli with latent periods of 50–100 msec.