Figure 1.

Specific ¹²⁵I-estradiol binding can be detected in the rat hypothalamus and amygdala. Film autoradiograms of coronal forebrain sections from ovariectomized rats treated with ¹²⁵I-estradiol (1 mCi) after pretreatment with vehicle (left) or unlabeled (cold) estradiol (250 μg/kg; right). ¹²⁵I-estradiol binding was apparent in several hypothalamic nuclei and the amygdala. Rats treated with cold estradiol before ¹²⁵I-estradiol had no detectable binding. ¹⁴C microscales: range 1.15–32.7 kBq/g, 31–883 nCi/g. AMYG, Amygdala; ARC, arcuate nucleus; BST, bed nucleus of the stria terminalis; POA, preoptic area; PVN, paraventricular nucleus of the hypothalamus; PvPO, periventricular hypothalamus; SON, supraoptic nucleus; VMH, ventromedial hypothalamus. Bar, 5 mm.