Estrogen receptor beta and progesterone receptor mRNA in the intergeniculate leaflet of the female rat

The present study was undertaken to explore the possibility that the integr ation of hormonal cues in the regulation of neuroendocrine mechanisms may o ccur outside of the hypothalamus at the level of the lateral geniculate bod y. In situ hybridization for mRNA encoding estrogen receptor beta and proge sterone receptor was carried out on sections containing the lateral genicul ate body using [S-35]-labeled antisense riboprobes. Labeled cells were pres ent in different limbic and hypothalamic sites as described previously, Pop ulations of cells distributed homogeneously in the ventral lateral genicula te nucleus and intergeniculate leaflet were also found to express mRNA for estrogen receptor beta and progesterone receptor. The dorsal lateral genicu late nucleus lacked specific labeling for either type of gonadal steroid ho rmone receptor mRNA. The present observation together with the recent demon stration of a direct pathway between the intergeniculate leaflet and hypoth alamic neuroendocrine cells indicate that integration of hormonal and photi c stimuli in the central regulation of endocrine mechanisms occurs outside of the hypothalamus in the lateral geniculate body. (C) 1999 Elsevier Scien ce B.V. All rights reserved.