Interaction of hippocampal and neocortical neurons in emotionally negative situations in active and passive rabbits.

Cross-correlation histograms were used to compare the interaction of close-lying cells in the hippocampus (field CA1) and the parietal-temporal areas of the neocortex in active and passive rabbits during exposure to emotionally significant stimuli. Interaction of hippocampal neurons depended on the type of the behavioral response to the stimulus. The greatest changes from baseline were seen in active rabbits in orientational-investigative and active defensive reactions, while the greatest changes in passive animals were in freezing. In all states, cases of common inputs to hippocampal neurons were found more frequently in passive rabbits and excitatory links between neurons with short delays (up to 40 msec) were more frequent in active rabbits. Interaction of neocortical neurons, in contrast with hippocampal neurons, was less dependent on the type of behavioral response to the stimulus and the animal's behavioral strategy. These results provide evidence of individual-typological features in information processing in hippocampal field CA1 in active and passive animals in emotionally negative situations.