ABSTRACT
In the rat CNS, immunocytochemical studies show that
histaminergic neurons are exclusively located in the tuber-
omammillary nucleus (TMN) in the lateral part of the
posterior hypothalamus (1,2). These neurons project
widely to many different areas of the rat brain (3), and
histamine-immunoreactive fibers are numerous within and
between those hypothalamic nuclei that are involved in
the regulation of food intake and energy expenditure (4).
