|Sandra L. Petersen
Professor of Veterinary and Animal Sciences, University of Massachusetts
Associate Dean of the Graduate School
Director of the Northeast Alliance for Graduate Education and the Professoriate
Ph.D.: Oregon State University
Molecular and Cellular Mechanisms Underlying the Neural Control of Ovulation
The work in my laboratory focuses on the molecular and cellular mechanisms by which the ovary and brain communicate to ensure that the brain signal for ovulation is sent when ovarian follicles are fully mature. As follicles approach maturity, they release increasing amounts of estrogen and progesterone into the blood. The rise in circulating levels of these ovarian steroids signal specific neurons in the brain to increase release of the peptide, luteinizing hormone-releasing hormone (LHRH). This increased secretion of LHRH then triggers a surge release of luteinizing hormone (LH) from the pituitary gland, which, in turn, stimulates ovulation.
The goal of one project in the laboratory is to determine the transsynaptic signal transduction mechanisms by which estrogen and progesterone trigger changes in LHRH gene expression, translation, and release. Considering that LHRH neurons do not have classical estrogen or progesterone nuclear receptors, we are working to determine what neurotransmitter systems and signal transduction pathways convey information about steroid levels to LHRH neurons.
The goal of the second project in my laboratory is to determine how environmental pollutants that activate the arylhydrocarbon receptor (AhR) interfere with ovulation in mammals. The AhR is a basic/helix-loop-helix protein that acts as a ligand-activated transcription factor and mediates the toxic effects of halogenated aromatic hydrocarbons present as ubiquitous environmental contaminants. These contaminants are extremely stable and present in the body fat of animals, including humans, throughout the world. We are currently working to determine the mechanisms by which activation of the AhR interferes with estrogen action in cells of the brain and/or pituitary gland.
PETERSEN, S.L., AND P. MOURA (In Press). Sexual differentiation of the gonadotropin surge release mechanism: A new role for the canonical NfkB Signaling pathway. Frontiers in Neuroendocrinology.
INTLEKOFER, K.A. AND S.L. PETERSEN (2011). Estradiol and progesterone regulate multiple progestin signaling molecules in rat preoptic area and hypothalamus. Neuroscience 176:86-92
LIU, X., PORTEOUS, R., D'ANGLEMONT DE TASSIGNY, Z., COLLEDGE, W.H., PETERSEN, S.L. AND A.E. HERBISON (2011). Frequency-dependent recruitment of fast and slow neurotransmitter release controls gonadotropin-releasing hormone neuron excitability. J. Neuroscience 31(7):2421-2430
PORTEOUS, R., S.L. PETERSEN, S. HWA YEO, J.P. BHATTARAI, P. CIOFI, X. D'ANGLEMONT DE TASSIGNY, W.H. COLLEDGE, A. CARATY AND A.E. HERBISON (2011). Kisspeptin neurons co-express met-enkephalin and galanin in the rostral periventricular region of the female mouse hypothalamus. J. Comparative Neurology. 519(17):3456-3469
CAO, J., P. ZHANG, H. PATISAUL AND S.L. PETERSEN (2011). 2, 3, 7, 8 Tetrachlorodibenso-p-dioxin (TCDD) acts directly in lactotropes and gonadotropes to interfere with E2-dependent and independent regulation of preprolactin, glycoprotein alpha and luteininzing hormone beta (LHbeta) gene expression. Molecular and Cellular Endocrinology 333(2):151-159
KOKAY, I., S.L. PETERSEN AND D. GRATTAN (2011). Ientification of prolactin-sensitive GABA and kisspeptin neurons in regions of the rat hypothalamus involved in the control of fertility. Endocrinology 152(2):526-535
INTLEKOFER, K.A. AND S.L. PETERSEN (2011). Distribution of mRNAs encoding classical progestin receptor, progesterone membrane components 1 and 2, serpine mRNA binding protein 1, and progestin and adipoQ receptor family members 7 and 8 in rat forebrain. Neuroscience 172:55-65
MOURA P AND S.L. PETERSEN (2010). Estradiol acts through nuclear -and membrane- initiated mechanisms to maintain a balance between GABAergic and glutamatergic signaling in the brain: Implications of hormone replacement therapy. Reviews in the Neurosciences 21:363-380, 2010
HUDGENS, E., JI, L., CARPENTER C.D. AND S.L. PETERSEN (2009) The GAD2 promoter is a transcriptional target of estrogen receptor alpha (ERalpha) and ERbeta: A unifying hypothesis to explain diverse effects of estradiol. J Neuroscience 29(27):8790-8797
KRISHNAN, S., INTLEKOFER, K., AGGISON, L AND S.L. PETERSEN (2009) A new model of sex differentiation of the anteroventral periventricular nucleus: TRAF2-inhibiting protein-dependent suppression of prosurvival genes in developing male brain. PNAS 106(39): 16692-16697