The time distribution of the spike train activity of the neurons in the rabbit sensorimotor cortex during a rhythmic motor dominant]

A stationary excitation focus produced in rabbit cortex by rhythmical electrodermal paw stimulation was revealed by presentation of testing sound stimuli, which were earlier indifferent for an animal. The multiunit activity in the sensorimotor cortex was recorded. The neuronal pairs were detected with correlated discharges. Analysis of discharges in such pairs revealed the dominant incidence of conjugated impulses with the interval equal or close to 2 s, if the focus had been created by stimulation with the rhythmic interval 2 s. The dominant interval between discharges in a conjugated pair of neurons was equal of close to 3 s, if the rhythmic stimuli positions had been spaced 3 s. It was shown that the rhythmical nature of the dominant focus was maintained at the level of neuronal interactions, i.e., was of a systemic character. The acquired rhythm in conjugated cell activity was observed not only during summation in the moment of excitation transmission to the effector (i.e., when the dominant realized itself in the motor reaction), but within the periods between the testing stimuli.