The estrogen-sensitive neural system in the brain of female cats

Estrogens participate in the regulation of gonadotropin secretion and in the control of sexual and aggressive behavior. To elucidate the neuroanatomical substrate for these actions in the female cat, the topographical distribution of estrogen-concentrating cells in the brain was studied by autoradiography. One hour after the intravenous injection of 1 mCi (3 microgram) of 3H-estradiol in three adult ovariectomized cats, radioactivity was concentrated in the nuclei of neurons in several brain areas. Within the telencephalon, high concentrations of moderately to heavily labeled cells were found in the lateral and posterior septal nuclei (n.), bed n. of the stria terminalis (medial division), medial and central amygdaloid n., and amygdalo-hippocampal area. There were also many less strongly labeled cells in the ventral dentate gyrus. Within the diencephalon, many heavily labeled cells were distributed in the medial and periventricular preoptic n., anterior hypothalamic area, and infundibular, ventromedial, and periventricular hypothalamic n. In the brain stem, some labeled cells were located throughout the periaqueductal gray, and in the laminar spinal trigeminal n., n. of the solitary tract, n. incertus, marginal n. of the superior cerebellar peduncle, rostral linear n., and interfascicular n. Although minor differences were noted, the topographical distribution of estradiol-concentrating cells in the female cat brain agreed closely with that reported in other vertebrate species.