Projections from the superior agranular frontal cortex in the temporal sulcus to the macaque

The aim of this study was to investigate the organization of the projection s from the superior temporal sulcus (STS) to the various areas forming the agranular frontal cortex. Injections of retrograde neuronal tracers were ma de in the various agranular areas, in nine macaque monkeys, The results sho wed that two rostral premotor areas, F6 (pre-SMA) and FT and the ventrorost ral part of area F2 (F2vr) are targets of projections from the upper bank o f the STS (uSTS). F6 and the dorsorostral part of F7 (supplementary eye fie ld, SEF) are targets of projections from the rostral part of the uSTS, corr esponding to the so-called 'superior temporal polysensory area' (STP). In c ontrast, the ventral part of area F7 (not including the SEF) and F2vr are t argets of afferents from the caudal part of the uSTS. Ventral F7 is the tar get of weak afferents from the caudalmost and dorsalmost part of the uSTS ( area 7a), whilst F2vr is the target of projections from a relatively more r ostral and ventral sector of the uSTS, close to the fundus of the sulcus. T his sector should correspond to area MST. In conclusion, F6 and SEF receive high order information from STP, whereas ventral F7 and F2vr receive infor mation from areas of the dorsal visual stream.