Spontaneous alternating behavior, attention, and exploration: the effects of colchicine lesions in the rat hippocaompal formation

This study investigated perseverative behavior, attention, and exploratory behaviors via discrete lesions of the rat hippocampal formation. It was hypothesized that lesions which interrupted input to the hippocampus and output to cortical and subcortical regions would induce these behaviors. Forty-four male Long-Evan rats were randomly divided into four treatment groups: cerebral spinal fluid, and three colchicine lesioned groups, 10-COL, 15-COL, and 25-COL. The animals were compared based upon performance in a standard Tmaze to test perseveration. Behaviors were also observed in an activity chamber to measure locomotion, attention, and exploration. Animals in the 25-COL group demonstrated a significant increase in activity and perseveration as well as a decrease in exploration and attention compared to all other groups. Disrupting the convergence of information to the hippocampal formation interferes with output to subcortical and cortical regions, inducing behavioral changes associated with the structures of the hippocampal system