A-A″ At higher magnification CRF-positive cells (A, closed arrows) and STEP-positive (A′, open arrows) showed almost complete co-localization in the BNSTov (A″, double arrows). However, there are occasional STEP-immunoreactive neurons which do not appear to co-localize CRF (A″, open arrows). B-B″ STEP-positive neurons (B′, green, open arrows) do not co-localize with NPY (B, red, closed arrows), or ENK (C-C″). ENK-positive processes are observed to make perisomatic contacts with STEP-expressing neurons (C″, double arrow). (NPY-Neuropeptide Y, ENK-Enkephalin, 63x, scale bar 10 μm).