[Dynamics of driven rhythm in neuron in sensorimotor cerebral cortices in rabbit on electrodermal paw stimulation]

The dominant centre is a zone of proof higher excitation of neurons in the cortex of the brain, resulting from long stimulation or effector (in our case of a forepaw of an animal) or direct cortical representations of this effector. Besides of higher excitation and the firmness of excitation neurones, the dominant centre has two more very important properties--ability to summation (addition) coming to a cortex and extending on cortical neural networks excitations and inertia. Last property is shown what even in some days after the termination of the stimulations which have formed a dominant, in reply to testing stimulus (earlier indifferent for an animal) the centre is activated and puts in action effector. By means of irritation of a paw of rabbits rhythmic impulses of a current of threshold force us had been formed a rhythmic defensive dominant. Interconnected (coincidence) neuronal activity of the sensorimotor cortex of rabbits, in which the rhythmic defensive dominanta has been created, was investigated. Temporal of sequences intervals between the coincidence impulses in peaks of crosscorrelation histograms (CCH) was analyzed. Frequency of occurrence of the coincidence impulses (intervals between impulses), forming CCH was defined by means of "secondary" autocorrelation histograms (ACH) in during a minute. Peaks on "secondary" ACH showed prevalent intervals between of the coincidence impulses. For the further analysis only those peaks of "secondary" ACH, which prevailed over an average level of the histogram with significance p < 0.05 was used. It has been found that in the formed locus of the defensive dominant the coincidence impulses appear not only in the rhythm of stimulation applied in experiment-- s, but also in multiple beat to it (4, 6 and 8 s). Registration and analysis of neuronal activity were done after creation of a rhythmic dominant. At the beginning of each experiment (i.e. before a presentation of testing stimulus) single 2 --econd peaks were mainly observed, but doubles peaks of coincidence im-ulses appeared with latency 2, 4 or 6 s, were absent or appeared a few case. During application of testing stimulus a significant increase doubles peaks was observed. It is supposed, that application of testing stimulus strengthens already created earlier latent focus of excitation, which begin proved as a compli-ation of rhythm:.