Interaction of the cholinergic and catecholaminergic systems of the brain during a change in the motivational behavior of animals.

It is generally recognized that food-motivated reactions of animals occur with the participation of cortical and subcortical structures of the brain (hypothalamus, limbic-reticular complex), between which complex neurochemical interactions are established. It is believed that activation of various structures of the central nervous system at various levels of food-motivated excitation is associated with the peculiarities of the mediation of nerve impulses in the corresponding brain structures. Moreover, the concept of close structurofunctional interrelationships among various mediator systems of the brain, in particular, the cholinergic and catecholaminergic systems, are finding increasing confirmation. However, the corresponding positions are based primarily on electrophysiological and biochemical investigations, which give integrative indices for relatively large regions of brain tissue (in comparison with micro- and ultrastructures). The structurochemical interactions of the cholinergic and catecholaminergic systems of the brain in the regulation of food-motivated behavior of animals at the cellular and subcellular levels have practically not been studied. In connection with the aforementioned, we were interested in studying the activity of acetylcholinesterase (AChE) and monoamine oxidase (MAO), which participate in the metabolism of acetylcholine and catecholamines, respectively, in the process of a change in the food-motivated behavior of animals in the micro- and ultrastructures of certain hypothalamic nuclei and the cerebral cortex. In the present investigation we used methods of quantitative histochemistry and electron cytochemistry.