Neuroscience Graduate Program at UCSF
Chronic stress has a variety of effects on the organism, including changes in energy balance, behavior and responsivity to new stimuli. These effects of chronic stress are probably mediated in large part by the central corticotropin-releasing factor (CRF) neuronal system and glucocorticoids secreted from the adrenal gland in response to drive from hypothalamic CRF. Moreover, all of these are affected strongly by circadian rhythms. Broadly, our lab studies how these changes effected by chronic stress occur. Specifically, we are delineating: interaction(s) among the 4 medial hypothalamic nuclei that regulate energy balance; changes in brainstem and limbic system components that alter hypothalamic function in chronically stressed animals; and the interaction between gonadal and adrenal cortical hormones on regulation of ACTH secretion and energy balance. To pinpoint structures that may mediate recruitment of pathways under conditions of chronic stress, we use Fos-immunostaining to delineate increased neuronal activity; combination of Fos and in situ hybridization for peptide mRNA reveals the activated cell phenotype.
Akana SF, Dallman, MF Chronic cold in adrenalectomized, corticosterone (B)-treated rats: facilitated corticotropin responses to acute restraint emerge as B increases. Endocrinology 138:3249-3258, 1997.
Bhatnagar S, Dallman, MF Neuroanatomical basis for facilitation of hypothalamo-pituitary-adrenal responses to novel stress after chronic stress. Neuroscience 84:1025-1039, 1998.
Choi SJ, Wong LS, Yamat C, Dallman MF The hypothalamic ventromedial nuclei amplify circadian rhythms: do they contain a food-entrained oscillator? J Neurosci. 18:3843-3852, 1998.
Choi SJ, Dallman MF Hypothalamic obesity: multiple routes mediated by loss of function in medial cell groups. Endocrinology 140: in press, 1999.
Choi, SJ, Sparks R, Clay M, Dllman MF Rats with hypothalamic obesities are insensitive to central leptin injections. Endocrinology 140: in press, 1999.
Viau V, Chu A, Soriano L, Dallman MF Independent and overlapping effects of corticosterone and testosterone on CRF and AVP mRNA expression in the paraventricular nucleus of the hypothalamus and stress-induced ACTH release. J Neurosci in press, 1999.
Dallman MF, Bhatnagar S Chronic sress and energy balance: role of the hypothalamo-pituitary-adrenal axis. Handbook of Physiology, Vol 7, ed. McEwen BS, in press 1999.