ARM CHOICES IN A SUNBURST MAZE - EFFECTS OF HIPPOCAMPECTOMY IN THE RAT

Hippocampectomized, neocortically damaged and unoperated rats were tested for response dispositions in a sunburst maze following training over a fixed path. The arm choices of neocortically damaged and unoperated rats were significantly limited to two of six alternatives. Hippocampectomized rats exhibited random selection of alternatives and were significantly different from controls. The neocortically damaged and unoperated rats were retested under scopolamine and retained a normal nonrandom selection pattern suggesting that normal hippocampal function was not necessary for the retention of these response selections. In accordance with this hypothesis, hippocampectomized rats trained preoperatively and tested for postoperative retention also exhibited a non-random selection pattern similar to controls, but they differed significantly in exploratory behavior. Choice patterns were stable over retests in the three groups. These data are consistent with the theory that the hippocampus is crucial in the acquisition of normal spatial dispositions, however spatial information once acquired may be available in the absence of hippocampus. © 1979.