(a) Photomicrograph showing Nissl‐stained sections for cytoarchitectonic purposes of the PVH combined with enzymatic detection of PHAL from the dorsomedial BNST (experiment BNST#6). (b) High magnification of photomicrograph illustrating varicosities (arrows) and short collaterals ended by terminal boutons (arrowheads) in the neuroendocrine part of the PVH. (c) Photomicrograph illustrating PHAL from the dorsomedial BNST and Nissl‐stained sections in the neuroendocrine PVH. (c′) High magnification illustrating a long PHAL‐positive axon that displays numerous terminal boutons (arrowheads) close to nucleated cells labeled with Nissl in the lateral extremity of the neuroendocrine PVH. (d) Photomicrograph showing double immunodetection of PHAL‐positive fibers (red) from the dorsomedial BNST and neurons labeled with NeuN (cyan) in the neuroendocrine part of the PVH and the periventricular nucleus (pv) (experiment BNST#2). (e) High magnification of PHAL‐positive fibers (red) from the dorsomedial BNST in the vicinity of a neuron labeled with NeuN (cyan) in the neuroendocrine PVH (experiment BNST#2). (f) 3D reconstruction using Imaris software of PHAL‐positive fibers (red) from the dorsomedial BNST in contact with a PVH neuron (white arrow, cyan). (g, h) Photomicrographs showing Crh mRNA‐expressing cells (orange) and DAPI counterstaining (white) at two distinct levels of the neuroendocrine PVH. Low (i) and high magnifications (j) of PHAL and Nissl‐stained sections in the posterior part of the PVH (experiment BNST#6). (k) Photomicrograph showing double immunodetection of PHAL‐positive fibers (red) from the dorsomedial BNST and neurons labeled with NeuN (cyan) in the posterior part of the PVH (experiment BNST#2). The autonomic part of the PVH is observed in the lateral part of the PVH while the medial part contains the parvicellular neurons. AHN, anterior nucleus of the hypothalamus; fx, fornix; pv, periventricular nucleus; mpd, medial parvicellular part, dorsal zone of the PVH; pml, posterior magnocellular part, lateral zone of the PVH; pmm, posterior magnocellular part, medial zone of the PVH; PVH, paraventricular nucleus of the hypothalamus; VMH, ventromedial nucleus of the hypothalamus; V3, third ventricle. Scale bars are shown in the figure [Color figure can be viewed at wileyonlinelibrary.com]