[The plasticity of systemic brain mechanisms].

Mechanisms of plasticity of the main components (dominant motivation and reinforcement) of systemic behavioural act organisation are considered. It is shown that dominant motivation changes different properties of brain neurones including their specific sensitivity to neuromediators and neuropeptides. Reinforcement in its turn modifies the properties of brain neurones which take part in dominant motivation. The foregoing reinforcement influences the modification of genetic apparatus of neurones involved in dominant motivation and, as a consequence, they begin to express specific information molecules under the influence of dominant motivation in the subsequent formation of the corresponding drive. The information molecules organise a corresponding behaviour. Plasticity properties of brain neurones are mostly revealed in conflict situations leading to emotional stress. Reorganisation of chemical integration of limbic-reticular neurones takes place under emotional stress. Oligopeptides play the leading role in these processes. It is shown that oligopeptides are able to compensate the functions of damaged limbic-reticular brain structures.