Active and passive behavior of animals during the postresuscitation period.

Behavioral reactions (open-field test, elevated plus-maze, pain stress, and feeding behavior) were studied in various periods after clinical death caused by circulatory arrest for 10 or 15 min. We revealed two different phases of behavioral changes: active behavior directed at attaining a specific goal and passive behavior directed towards isolation of the organism from external signals and functional minimization. Active behavior determined by pathological excitation in the central nervous system increased the severity of structural damage to hippocampal CA1 neurons during the postresuscitation period. By contrast, passive behavior and minimization of functions preserved structural integrity in these neurons.