Bilateral distribution of projection neurons directed to medial prefrontal and lateral prefrontal cortices. Coronal sections through the prefrontal cortex showing labeled neurons in ipsilateral (ipsi) and contralateral (contra) hemispheres after infection of tracers in three cases. Labeled neurons were found in layers II-III (blue dots) and in layers V-VI (red dots). In all cases rostral sections are shown on the left, and caudal on the right. (Top)Injection of HRP-WGA (A, black area) was in medial area 32. (Center)Injection of HRP-WGA was in medial area 9 (not shown). (Bottom)Injection of fast blue was in dorsal area 46 (not shown). Dotted lines through the cortex in the coronal sections show the bottom of layer IV. Abbreviations as in Figure 5.