Coronal section through the mPFC in Nissl-stained section showing ventral border of ROI adopted in this study. The limits between areas IL and DP are marked mainly by neuronal density in layer II, which is narrow and compact in IL, but wider and loose in DP (arrows). In addition, lamination in IL is more visible than in DP. (IL, infralimbic area; DP, dorsal peduncular cortex; DTT, dorsal tenia tecta. Scale bar = 1 mm).