MULTIPLE SPATIAL BEHAVIORAL-CORRELATES FOR CELLS IN THE RAT POSTSUBICULUM - MULTIPLE-REGRESSION ANALYSIS AND COMPARISON TO OTHER HIPPOCAMPAL AREAS

Head direction cells in the rat postsubiculum fire in relation to the momentary directional heading of the animal, with each cell firing onl y when the animal faces in one particular direction. To understand how this signal might he generated, one useful step is to discover what o ther cell types, in addition to the head direction cells, may exist in the postsubiculum, since these cells might be involved in helping to generate the direction-specific activity. Here, postsubicular cells we re recorded as animals navigated in a cylindrical recording chamber. I t was found that, in addition to head direction cells, the postsubicul um contains cells that show several other types of spatial/behavioral correlates, including angular velocity of the head, running speed, and location. Ten percent of the cells were classified as angular velocit y cells, and they resembled vestibular afferent fibers, with antagonis tic responses to clockwise versus counterclockwise turns. In addition, numerous other cell types were observed. These latter cells were hard er to classify, but all showed a significant correlation with one or m ore of the above variables. These findings suggest that the head direc tion cell signal may be at least partly based on the angular velocity, running speed, and locational signals observed here.