Testosterone and its metabolites are the principal gonadal hormones responsible for sexual differentiation of the brain. However, the relative roles of the androgen receptor (AR) vs. the estrogen receptor in specific aspects of this process remain unclear due to the intracellular metabolism of testosterone to active androgenic and estrogenic compounds. In this study, we used an 35S-labeled ribo...

Regulation of ACTH secretion changes between early (40 d) and late (60 d) puberty in male rats. We tested whether this occurs because of activating effects of testosterone on the brain. We measured testosterone and ACTH responses to repeated restraint in adrenalectomized, corticosterone-replaced rats entering and leaving puberty with or without treatment with flutamide, a nonsteroidal androgen-...

Rodents exposed to a 15-min pretest swim in the forced swimming test (FST) exhibit prolonged immobility in a subsequent 5-min test swim, and antidepressant treatment before the test swim reduces immobility. At present, neuronal circuits recruited by antidepressant before the test swim remain unclear, and also less is known about whether antidepressants with different mechanisms of action could ...

King, Bruce M. Amygdaloid lesion-induced obesity: relation to sexual behavior, olfaction, and the ventromedial hypothalamus. Am J Physiol Regul Integr Comp Physiol 291: R1201–R1214, 2006. First published June 15, 2006; doi:10.1152/ajpregu.00199.2006.—Lesions of the amygdala have long been known to produce hyperphagia and obesity in cats, dogs, and monkeys, but only recently have studies with ra...

ÐIncreased activity of the immediate-early gene c-fos can be observed in many areas of the lactating rat brain after dams physically interact with pups and display maternal behaviour. These sites include the medial preoptic area, ventral bed nucleus of the stria terminalis, and the ventrolateral caudal periaqueductal gray, each of which is critical for the normal performance of particular mater...