Spatial Orientation and Dynamics of Papez Circuit

Although Papez circuit was initially proposed as a neural substrate for emotions, recent findings of head-direction cells demonstrate that some parts of the structure are involved with representation of spatial orientation. We discuss several problems related to the dynamics of the spatial representation, including (1) reduction of the dynamics of coupled cell groups to that of a simple cell group, in which the formulation of the shift mechanism has been determined uniquely, (2) the relation between dynamic behaviors of coupled cell groups and lesion results, and (3) the limitation of one-dimensional spatial representation in geometric phase problem.