Gh mRNA in (A) the cerebellum, showing a significant increase in the relative quantity (RQ) of Gh mRNA in estradiol-treated animals of all genotypes; (B) the hippocampus, a significant effect of estradiol on Gh RQ was noted; and (C) the hypothalamus where effects of both sex chromosomes and gonadal sex were observed. Adult mice from the four core genotypes—XY males (black bars), XX males (horizontal striped bars), XX females (white bars), and XY females (diagonal striped bars)—were gonadectomized and treated with estradiol (E) or given empty implants. For the cerebellum: blank: XYM N = 7, XXM N = 7, XXF N = 6, XYF N = 7; E2: XYM N = 6, XXM N = 8, XXF N = 4, XYF N = 5. In the hippocampus: blank: XYM N = 6, XXM N = 7, XXF N = 6, XYF N = 5; E2: XYM N = 9, XXM N = 8, XXF N = 6, XYF N = 6. In the hypothalamus: N = 6 for all groups. The single asterisks indicate significant effect of estradiol (P < 0.05). The double asterisks indicate significant sex difference (P < 0.05). The plus symbols indicate mice in the XY male group which are significantly different from mice in the XX male and XY female groups (P < 0.05).