Deficits in allothetic and idiothetic spatial behavior in rats with posterior cingulate cortex lesions

The cingulate cortex plays a central role in bridging neocortical and limbi c structures involved in allothetic navigation, a form of navigation requir ing the use of external cues. Animals can also navigate using idiothetic cu es, which are cues generated by self-movement. but there have been no defin itive tests of whether cingulate cortex also plays a role in idiothetic nav igation. Rats with anterior cingulate (medial frontal) and posterior cingul ate cortex (retrosplenial) suction ablations were trained to search for lar ge food pellets on an open table. and the accuracy with which they returned home with the food was measured. In the idiothetic task they searched for food from a novel starting location under infrared light, and with surface olfactory cues displaced. The rats also received two tests of allothetic na vigation. They were tested on a matching to-place task in which they forage d for food from a number of successively presented new locations under norm al room light, and they were trained to locate a hidden platform in a swimm ing pool (Morris place task). The group with posterior cingulate cortex les ions was severely impaired on all of the navigation tasks whereas the group with anterior cingulate cortex lesions displayed no deficit on the idiothe tic task and only moderate deficits on the other tasks. The results demonst rate a role for posterior cingulate region in idiothetic navigation. (C) 20 01 Elsevier Science B.V. All rights reserved.