[Correlation between the retention of defensive conditioned reflexes and rat brain acetylcholinesterase activity].

The comparison of the characteristics of temporary connection retention (repeated elaboration) with the activity of acetylcholinesterase (AChE) of the motor, visual cerebral cortical areas and hippocampus was done at different time (1, 2 and 4 weeks) following elaboration of defensive conditioned reflexes (CR) in rats in a chamber of two-way avoidance with electrified floor. The maximal retention of CR was observed 2 weeks after the initial elaboration. The dynamics of AChE activity on the whole doesn't correspond to the changes in CR retention. Pronounced AChE activity decrease in the motor and visual cortex was observed during CR reproduction 4 weeks after elaboration. Significant differences by this parameter were observed between trained animals and the rats, presented with non-paired photic and electrical stimuli (active control).