[Reorganization of the synaptic inputs of the sensorimotor cortex to the red nucleus after the destruction of the cerebellar nucleus interpositus in adult cats]. / Reorganizatsiia sinapticheskikh vkhodov sensomotornoi kory mozga v krasnoe iadro posle razrusheniia promezhutochnogo iadka mozzhechka u vzroslykh koshek.

Responses of the red nucleus to neurons to stimulation of the ipsilateral sensorimotor cortex have been studied in acute cats with preliminary lesion of the contralateral cerebellar nucleus interpositus (exposition from two weeks to a year and longer period) by intracellular recording technique. Acceleration of the monosynaptic EPSPs rise testifying to formation of the terminal dendrosomatic sprouting of axons of the corticorubral neurons on proximal segments of the somatodendritic membrane of the red nucleus neurons was observed. Various division of the sensorimotor cortex were unequally involved in the process of reorganization of synaptic inputs on the level of individual red nucleus neurons.

Synaptic responses of red nucleus neurons in the alert cat to cortical and cerebellar inputs.

Postsynaptic potentials of neurons of the red nucleus (RN), evoked to stimulation of the sensorimotor region of the cerebral cortex and cerebellar nucleus interpositus, were studied in chronic experiments on alert cats by means of an intracellular recording technique. Movements of the animals were restricted by rigid fixation (through a special device previously attached to the head) of the animal's head on the frame of the stereotaxic apparatus. Rubrospinal neurons were identified according to their antidromic activation in response to stimulation of the rubrospinal tract at the decussation level. A decrease in the critical level of depolarization necessary for spike generation was shown to be a characteristic peculiarity for mono- and polysynaptic reaction of the RN neurons in the alert animals. A rare possibility of recording separate EPSPs, the presence of burst discharges of rubrospinal neurons as well as a higher activity of RN interneurons was observed.

[Synaptic responses of neurons of the red nucleus of the alert cat to stimulation of the sensomotor area of the cortex and the nucleus interpositus of the cerebellum]. / Sinapticheskie reaktsii neironov krasnogo iadra bodrstvuiushchei koshki na stimuliatsiiu sensomotornoi oblasti kory i promezhutochnogo iadra mozzhechka.

Postsynaptic potentials of the red nucleus neurons evoked by stimulation of the cortical sensomotor region and the cerebellar nucleus interpositus were studied in chronic experiments on awake cats by means of intracellules revording. Rubro-spinal neurons identified by their antidromic activation in response to the stimulation. A decrease of the critical depolarization level was a specific feature for mono- and polysynaptic responses of the red nucleus neurons in alert animals. Isolated EPSPs, therefore, were rarely recorded as well as a great number of polysynaptic potentials. Burst discharges of rubro-spinal neurons and intensive activity of the red nucleus interneurons, were observed.

[Representation of cutaneous sensitivity in the cat red nucleus]. / Osobennosti predstavitel'stva kozhnoi chuvstvitel'nosti v krasnom iadre koshki

Responses of the red nucleus neurons to the skin stimulation in unanestethized chronic cats showed most of the neurons to have wide receptive fields with areas stimulation of which caused an extremely intense and stable activation of respective neurons. The somatotopic principle of the cutaneous representation in the red nucleus was revealed. Destruction of the cerebellar nuclei and sensory motor cortex lowered the spontaneous activity of the red nucleus neurons, changed their responses to the skin stimulation, and caused the narrowing and the redistribution of the peripheral receptive fields preserving, however, the somatotopic character of the cutaneous representation in the red nucleus.