ORGANIZATION OF FACE REPRESENTATION IN THE CINGULATE CORTEX OF THE RHESUS-MONKEY

Neuroanatomical and electrophysiological methods were used to investig ate the organization of face representation in the cingulate gyrus of four rhesus monkeys. Injections of fluorescent tracers placed into ele ctrophysiologically defined sectors of the primary (M1) and supplement ary (M2) motor cortices demonstrated that the rostral part of area 24c and the rostral part of area 23c send projections to the face represe ntations of M1 and M2. Injections of biotinylated dextran amine involv ing the rostral part of area 24c and rostral part of area 23c demonstr ated a direct projection from both areas to the facial nucleus of the pens. Our data suggest that areas 24c (M3) and 23c (M4) each contain a face representation which directly affects cortical as well as subcor tical neural centers controlling facial activity.