ESTROGEN RECEPTOR-ALPHA-IMMUNOREACTIVE NEURONS IN THE PERIAQUEDUCTAL GRAY OF THE ADULT OVARIECTOMIZED FEMALE CAT

Anatomical and physiological studies in rodent and cat have shown that distinct parts of the midbrain periaqueductal gray (FAG) are importan t for the estrogen dependent, female reproductive behavior. The presen t study gives a detailed overview of the estrogen receptor-alpha-immun oreactive (ER-IR) neurons in the FAG in the cat. ER-IR neurons were fo und throughout the rostrocaudal extent of the FAG and laterally adjace nt tegmentum, but were most numerous at caudal levels. The lateral and dorsal PAG contained most ER-IR neurons, whereas moderate numbers wer e found dorsolaterally. In these areas, only very few ER-IR neurons we re found near the border of the ependymal layer. Except for the rostra l dorsal raphe nucleus, the central PAG contained only few ER-IR neuro ns. (C) 1998 Elsevier Science Ireland Ltd.