ESTROGEN-RECEPTOR IMMUNOREACTIVITY IN HAMSTER BRAIN - PREOPTIC AREA, HYPOTHALAMUS AND AMYGDALA

The distribution of estrogen-receptor containing cells in the preoptic area, hypothalamus and amygdala of female Syrian hamster brain was st udied by immunocytochemical methods. Dense populations of estrogen-rec eptor immunoreactive (ER-IR) cells were found in the medial preoptic a rea, the bed nucleus of the stria terminalis, amygdala, ventral and la teral parts of the hypothalamus, and the arcuate nucleus. Injection of estradiol caused a decrease in estrogen-receptor immunoreactivity (ER IR) containing cells within one hour, a decrease that may reflect a ch ange in the ability of the occupied estrogen receptor to bind the part icular antibody (H222) used rather than down-regulation of the estroge n receptor. Our findings on the distribution of estrogen-receptor cont aining cells in these areas using an immunocytochemical technique are consistent with and extend the findings of others using autoradiograph ic and in vitro binding techniques to study estrogen receptor distribu tion in hamster brain.