[Chemical integration in mechanisms of brain plasticity].

The paper analyzes investigations on brain functions from the viewpoint of P. K. Anokhin's theory of functional systems. Brain plasticity is postulated to be the result of convergence of various excitations on single brain neurons and of chemical integration of brain transmitters and modulators of peptide origin in the realization of biological motivations. Numerous findings of duplication of various neurotransmitters and oligopeptides in the central mechanisms of biological motivations, chemical rearrangement in the recovery period after the lateral hypothalamic syndrome when bilateral motivational centers of the hypothalamus were coagulated suggests that there is chemical compensation in the brain activity for homeostatic maintenance. The plasticity of extrahypothalamic brain structures are postulated to be more expressed as compared to the specific activities of hypothalamic, brain stem, and spinal cord structures.