Influence of brain stem structures on the formation of the defensive behavior of animals.

The dependence of the dominant form of the defensive behavior of white male mongrel rats on the functional state of the brain stem inhibitory locomotor system has been studied in chronic experiments. It was established that the electrolytic destruction of the inhibitory zones of the cuneate nucleus of the midbrain, the medial parabrachial nucleus, the central and great nuclei of the raphé leads to the dominance of active defensive reactions in animals in confrontations with partners. The opposite effect is exerted by local injection of kainic acid into these regions of the brainstem. It is hypothesized that the functional state of the brain stem inhibitory locomotor system can exert a modulating influence on the formation of the defensive behavior of animals.