Effect of elaboration of a local motor-food conditioned reflex and reconditioning its effector component on the protein content in neurons of the motor cortex of rats.

Elaboration in rats of a local motor-food conditioned reflex in the form of pressing a lever by a preferred foot was accompanied by an increase of the protein content in interneurons in the absence of a change of this index in large and medium pyramidal neurons in the V layer of the motor cortex in the projection of the preferred foot in comparison with the symmetric point of the opposite hemisphere. Reconditioning of the conditioned reflex, i.e., its accomplishment by the nonpreferred foot, was accompanied by a decrease of the protein content in large pyramidal neurons of the V layer of the motor cortex in the absence of changes in the dry mass of interneurons in the projection of the nonpreferred foot in comparison with the projection of the preferred foot. Pyramidal neurons of the III layer reacted by an insignificant change in the protein content both in the case of elaborating the conditioned reflex and reconditioning of its effector component. It is suggested that the pyramidal neurons of the III layer, large pyramidal neurons and interneurons of the V layer of the motor cortex are involved in metabolic provision of elaboration of the local motor-food conditioned reflex and in the formation of new motor coordination at different stages of these processes.