Fig. 7. In situ hybridizations and dark-field autoradiograms of D1 (A) and D5 (B) mRNA. Modest distribution of D1, but not D5, dopamine receptor mRNA is visualized in the ventromedial nucleus of the hypothalamus (VMH) 48 hr after estrogen priming of ovariectomized female (E2F inD1A, B; D5A, B) and in the VMH of male (M in D1 C, D; D5C, D) rats. A D1 dopamine receptor cRNA probe transcribed from a rat D1 dopamine receptor cDNA and a D5 dopamine receptor riboprobe generated from a partial rat D5 dopamine receptor cDNA were used.A and C are at low magnification, andB and D are at higher magnification.HIP, Hippocampus; CPu, caudate putamen;3V, third ventricle; Re, reuniens thalamic nucleus; En, endopiriform nucleus.