[Neuronal correlates of changes in the time parameters of motor reactions in rabbits after tonic immobilization]

The latent excitation focus in the sensorimotor cortex of rabbits was formed by a series of pulses of the threshold current applied on a paw with 2-second intervals. After repeated applications of the routine immobilization procedure, besides the 2-second starts of the paw in response to testing stimulus, spontaneous starts appeared with the intervals close to 3 and 4 seconds. The analysis of the coincident (interconnected) activity of pairs of nearby neurons in the sensorimotor cortex of three rabbits repeatedly exposed to the immobilization procedure showed that (a) in situations when animals made movements with the intervals of 2 seconds, the 2-second rhythm prevailed in the coincident activity of neurons; (b) during movements made with the 3-second interval, a 3-second rhythm was more frequently revealed in the coincident activity of cells, (c) in the situations when the animals did not make movements, either 2-, or 3-second rhythms were equiprobably observed in the connected activity of nearby neurons. In all these three situations, the 2-second rhythm prevailed in the connected activity of distant neurons, i.e., the rhythm which was imposed to animals during formation of the latent center of excitation.