Fig. 1.

Hypocretinergic neurons are intermingled with MCHergic neurons in the postero-lateral hypothalamus. (A) Photomicrographs of the postero-lateral hypothalamic area of the cat. The sections were immunostained for hypocretin (black, arrows) and MCH (brown, arrowheads). Sections were processed utilizing the ABC method and the DAB–H₂O₂ reaction to detect peroxidase activity. This reaction was enhanced with nickel to label hypocretinergic cells. Calibration bars: 50 μm. (B) Location of MCHergic and hypocretinergic neurons in the postero-lateral hypothalamus of a representative cat. Camera lucida drawings of MCHergic (on the left, black circles) and hypocretinergic neuronal bodies (on the right, red circles) in the postero-lateral hypothalamus. The neurons are from the same hemi-hypothalamus (reflected in the figure). Camera lucida drawings were obtained from adjacent sections that were immunostained for MCH for Hcrt-2, respectively; these sections were counterstained with Pyronin-Y. The demarcation and nomenclature of cell groups in the cat hypothalamus are based on Berman and Jones, as well as Bleier׳s work [105,106]. DM, dorsomedial nucleus; EN, entopeduncular nucleus; fx, fornix; HDA, dorsal hypothalamic area; HLA, lateral hypothalamic area; INF, infundibular nucleus; mt, mammillothalamic tract; PAH, paraventricular nucleus; PEH, periventricular complex; PVH, parvocellular nucleus; TCA, area of the tuber cinereum; VM, ventromedial nucleus; ZI, zona incerta; 3V, third ventricle. Modified from [9]. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)