Localization of histaminergic perikarya (closed circles) in tuberomammillary nucleus and disposition of main histaminergic pathways (arrows) in rat brain. Left: frontal section of caudal hypothalamus. Right: sagittal section of brain. Abbreviations: AH, anterior hypothalamic area; Arc, arcuate nucleus; cc, corpus callosum; Cer, cerebellum; CG, central gray; CX, cerebral cortex; DR, dorsal raphe nucleus; f, fornix; Hip, hippocampus; LS, lateral septum; MD, mediodorsal thalamus; MMn, medial mammillary nucleus median part; OB, olfactory bulb; Pn, pontine nuclei; Sol, nucleus of solitary tract; Sox, supraoptic decussation; SuM, supramammillary nucleus; TMdiff, tuberomammillary nucleus diffuse part; TMVr, ventral tuberomammillary subgroup rostral part; VDB, nucleus of vertical limb of diagonal band; VMH, ventromedial hypothalamic nucleus.