Laboratory of Preclinical Neuroendocrinology
See Faculty Bio
The long-term objective of our research is to determine the cellular and molecular mechanisms by which steroid hormones regulate neuronal function, including behavior. Using rats as our model system, many of our studies focus on actions of the ovarian steroids, estradiol and progesterone, in brain regions (e.g., hypothalamus, preoptic area) that regulate female reproductive physiology. A combination of in vitro and in vivo approaches are employed to examine hormonal modulation of norepinephrine, GABA and glutamate release in the hypothalamus and preoptic area as well as the mechanisms by which these neurotransmitters act in the hypothalamus to regulate female reproductive behavior. Additional studies utilizing biochemical and molecular biological techniques are investigating the hypothesis that estradiol and progesterone extensively modify noradrenergic receptor-mediated signal transduction by at least two distinct mechanisms: (1) regulation of gene transcription, most notably of the a1B -adrenoceptor, and (2) regulation of b-,a1 - and a2 -adrenoceptor coupling to G proteins that regulate effector enzymes including adenylyl cyclase and phospholipase C. To this end some of our areas of study include:
- The use of molecular probes and immunoblotting to assess the effects of estradiol on cellular components that modulate receptor-G protein coupling
- The examination of the influence of ovarian steroids on signaling through the nitric oxide-guanylyl cyclase pathways in the hypothalamus
- Influences of ovarian hormones in brain regions not generally associated with reproductive function.
- Investigation of the influence of ovarian steroids on seizure susceptibility in female rats.
Gonzalez-Flores O. Guerra-Araiza C. Cerbon M. Camacho-Arroyo I. Etgen AM. The 26S Proteasome Participates in the Sequential Inhibition of Estrous Behavior Induced by Progesterone in Rats. Endocrinology, 2004 View Text via PubMed
Gonzalez-Flores O. Etgen AM. The nitric oxide pathway participates in estrous behavior induced by progesterone and some of its ring A-reduced metabolites. Horm Behav. 45: 50-7, 2004 View Text via PubMed
Etgen AM. Acosta-Martinez M. Participation of growth factor signal transduction pathways in estradiol facilitation of female reproductive behavior. Endocrinology. 144: 3828-35, 2003 View Text via PubMed
Acosta-Martinez M. Etgen AM. Estrogen modulation of mu-opioid receptor-stimulated [35S]-GTP-gamma-S binding in female rat brain visualized by in vitro autoradiography. Neuroendocrinology. 76: 235-42, 2002 View Text via PubMed
Acosta-Martinez M. Etgen AM. The role of delta-opioid receptors in estrogen facilitation of lordosis behavior. Behav Brain Res. 136: 93-102, 2002 View Text via PubMed
Etgen AM. Morales JC. Somatosensory stimuli evoke norepinephrine release in the anterior ventromedial hypothalamus of sexually receptive female rats. J Neuroendocrinol. 14: 213-8, 2002 View Text via PubMed
Quesada A. Etgen AM. Functional interactions between estrogen and insulin-like growth factor-I in the regulation of alpha 1B-adrenoceptors and female reproductive function. J Neurosci. 22: 2401-8, 2002 View Text via PubMed
Jover T. Tanaka H. Calderone A. Oguro K. Bennett MV. Etgen AM. Zukin RS. Estrogen protects against global ischemia-induced neuronal death and prevents activation of apoptotic signaling cascades in the hippocampal CA1. J Neurosci. 22: 2115-24, 2002 View Text via PubMed
Acosta-Martinez M. Etgen AM. Activation of mu-opioid receptors inhibits lordosis behavior in estrogen and progesterone-primed female rats. Horm Behav. 41: 88-100, 2002 View Text via PubMed
Jackson A. Etgen AM. Inhibition of lordosis behavior by intrahypothalamic infusion of a protein kinase G antagonist. Brain Res. 919: 175-8, 2001 View Text via PubMed
Fiber JM. Etgen AM. Modulation of GABA-augmented norepinephrine release in female rat brain slices by opioids and adenosine. Neurochem Res. 26: 853-8, 2001 View Text via PubMed
Etgen AM. Ansonoff MA. Quesada A. Mechanisms of ovarian steroid regulation of norepinephrine receptor-mediated signal transduction in the hypothalamus: implications for female reproductive physiology. Horm Behav. 40: 169-77, 2001 View Text via PubMed
Ansonoff MA. Etgen AM. Receptor phosphorylation mediates estradiol reduction of alpha2-adrenoceptor coupling to G protein in the hypothalamus of female rats. Endocrine. 14: 165-74, 2001 View Text via PubMed
Ansonoff MA. Etgen AM. Estrogen increases G protein coupled receptor kinase 2 in the cortex of female rats. Brain Res. 898: 186-9, 2001 View Text via PubMed
Jackson A. Etgen AM. Estrogen modulates 5-HT(1A) agonist inhibition of lordosis behavior but not binding of [(3)H]-8-OH-DPAT. Pharmacol Biochem Behav. 68: 221-7, 2001 View Text via PubMed
Quesada A. Etgen AM. Insulin-like growth factor-1 regulation of alpha(1)-adrenergic receptor signaling is estradiol dependent in the preoptic area and hypothalamus of female rats. Endocrinology. 142: 599-607, 2001 View Text via PubMed
Ansonoff MA. Etgen AM. Evidence that oestradiol attenuates beta-adrenoceptor function in the hypothalamus of female rats by altering receptor phosphorylation and sequestration. J Neuroendocrinol. 12: 1060-6, 2000 View Text via PubMed
Quesada A, Etgen AM. Tyrosine kinase effects on adrenoceptor-stimulated cyclic AMP accumulation in preoptic area and hypothalamus of female rats: modulation by estradiol. Brain Res. 2000 Apr 7;861(1):117-25.
Etgen AM, Chu HP, Fiber JM, Karkanias GB, Morales JM. Hormonal integration of neurochemical and sensory signals governing female reproductive behavior. Behav Brain Res. 1999 Nov 1;105(1):93-103. Review.
Velisek L, Veliskova J, Etgen AM, Stanton PK, Moshe SL. Region-specific modulation of limbic seizure susceptibility by ovarian steroids. Brain Res. 1999 Sep 18;842(1):132-8.
Acosta-Martinez M, Fiber JM, Brown RD, Etgen AM. Localization of alpha1B-adrenergic receptor in female rat brain regions involved in stress and neuroendocrine function. Neurochem Int. 1999 Nov;35(5):383-91.
Chu HP. Etgen AM. Ovarian hormone dependence of alpha(1)-adrenoceptor activation of the nitric oxide-cGMP pathway: Relevance for hormonal facilitation of lordosis behavior. Journal of Neuroscience. 19: (16) 7191-7197,1999 AUG. Full Text PDF Format - Requires Acrobat - Educational Use Only
Chu HP. Morales JC. Etgen AM. Cyclic GMP may potentiate lordosis behaviour by progesterone receptor activation. Journal of Neuroendocrinology. 11:107-113, 1999 FEB.
Karkanias GB. Morales JC. Etgen AM. Effects of diabetes and estradiol on norepinephrine release in female rat hypothalamus, preoptic area and cortex. Neuroendocrinology. 68:30-36, 1998 July
Ansonoff MA. Etgen AM. Estradiol elevates protein kinase C catalytic activity in the preoptic area of female rats. Endocrinology. 139:3050-3056, 1998 July Full Text PDF Format - Requires Acrobat - Educational Use Only
Fiber JM. Etgen AM. Evidence that GABA augmentation of norepinephrine release is mediated by interneurons. Brain Res. 790[1-2]:329-333, 1998 Apr. Full Text PDF Format - Requires Acrobat - Educational Use Only
Chu HP. Etgen AM. A potential role of cyclic GMP in the regulation of lordosis behavior of female rats. Horm Behav. 32:125-132, 1997 Oct.
Fiber JM. Etgen AM. GABA augments basal and electrically stimulated 3H-norepinephrine release in hypothalamic, preoptic area and cortical slices of female rats. Neurochem Int. 31:769-780, 1997 Dec. Full Text PDF Format - Requires Acrobat - Educational Use Only
Karkanias GB. Li CS. Etgen AM. Estradiol reduction of alpha 2-adrenoceptor binding in female rat cortex is correlated with decreases in alpha 2A/D-adrenoceptor messenger RNA. Neuroscience. 81:593-597, 1997 Dec.
Vathy I. Sokol J. Etgen AM. Gender-related differences exist in cortical [3H]nisoxetine binding and are not affected by prenatal morphine exposure. Neuroscience. 76:331-334, 1997 Jan.
Chu HP. Etgen AM. Effects of nitric oxide on stimulated release of norepinephrine from female rat hypothalamic slices. Brain Res. 741[1-2]:60-67, 1996 Nov.
Karkanias GB. Ansonoff MA. Etgen AM. Estradiol regulation of alpha 1b-adrenoceptor mRNA in female rat hypothalamus-preoptic area. Journal of Neuroendocrinology. 8(6): 449-455, 1996 June
Vathy I. Etgen AM. Effects of prenatal morphine and adult estrogen administration on mu-opioid inhibition of norepinephrine release from hypothalamic slices. Neuroendocrinology. 63(1): 61-68, 1996 Jan.
Brown LL. Pasi S. Etgen AM. Estrogen regulation of mu opioid receptor density in hypothalamic premammillary nuclei. Brain Research. 742(1-2): 347-351, 1996 Dec.
Fleischmann A. Sternheim A. Etgen AM. Li C. Grisaru N. Belmaker RH. Transcranial magnetic stimulation downregulates beta-adrenoreceptors in rat cortex. Journal of Neural Transmission. 103(11): 1361-1366, 1996
Karkanias GB. Petitti N. Etgen AM. Progesterone attenuation of alpha 1-adrenergic receptor stimulation of phosphoinositol hydrolysis in hypothalamus of estrogen-primed female rats. Endocrinology. 136(5): 1993-1999, 1995 May
Karkanias GB. Etgen AM. A thermodynamic analysis of estrogen regulation of alpha 2-adrenoceptor binding. Brain Research. 674(1): 26-32, 1995 Mar.
Etgen AM. Oxytocin does not act locally in the hypothalamus to elicit norepinephrine release. Brain Research. 703(1-2): 242-244, 1995 Dec.
Fleischmann A. Makman MH. Etgen AM. GABAA receptor activation induces GABA and glutamate release from preoptic area. Life Sciences. 56(20): 1665-1678, 1995
Karkanias GB. Etgen AM. Estradiol reduction of the agonist high affinity form of the alpha 2-adrenoceptor in the hypothalamus of female rats: identification as the alpha 2D subtype. Molecular Pharmacology. 45(3): 509-516, 1994 Mar.
Etgen AM. Karkanias GB. Estrogen regulation of noradrenergic signaling in the hypothalamus. Psychoneuroendocrinology. 19(5-7): 603-610, 1994
Saldivar-Gonzalez A. Fernandez-Guasti A. Etgen AM. Male rat sexual behavior induces changes in [3H]flunitrazepam binding. Brain Research. 611(2): 326-329, 1993 May
Ungar S. Makman MH. Morris SA. Etgen AM. Estrogen uncouples beta-adrenergic receptor from the stimulatory guanine nucleotide-binding protein in female rat hypothalamus. Endocrinology. 133(6): 2818-2826, 1993 Dec.
Vincent PA. Etgen AM. Steroid priming promotes oxytocin-induced norepinephrine release in the ventromedial hypothalamus of female rats. Brain Research. 620(2): 189-194, 1993 Aug.
Karkanias GB. Etgen AM. Estradiol attenuates alpha 2-adrenoceptor-mediated inhibition of hypothalamic norepinephrine release. Journal of Neuroscience. 13(8): 3448-3455, 1993 Aug.
Petitti N. Karkanias GB. Etgen AM. Estradiol selectively regulates alpha 1B-noradrenergic receptors in the hypothalamus and preoptic area. Journal of Neuroscience. 12(10): 3869-3876, 1992 Oct.
Fleischmann A. Makman MH. Etgen AM. Characterization of glutamate efflux from preoptic area synaptosomes. Neuropharmacology. 31(11): 1171-1178, 1992 Nov.
Petitti N. Etgen AM. Progesterone promotes rapid desensitization of alpha 1-adrenergic receptor augmentation of cAMP formation in rat hypothalamic slices. Neuroendocrinology. 55(1): 1-8, 1992 Jan.
Fleischmann A. Etgen AM. Makman MH. Estradiol plus progesterone promote glutamate-induced release of gamma-aminobutyric acid from preoptic area synaptosomes. Neuropharmacology. 31(8): 799-807, 1992 Aug.
Vathy I. van dJ. Vincent PA. Etgen AM. Intracranial dialysis and microinfusion studies suggest that morphine may act in the ventromedial hypothalamus to inhibit female rat sexual behavior. Hormones & Behavior. 25(3): 354-366, 1991 Sept.
Petitti N. Etgen AM. Protein kinase C and phospholipase C mediate alpha 1- and beta-adrenoceptor intercommunication in rat hypothalamic slices. Journal of Neurochemistry. 56(2): 628-635, 1991 Feb.
Fleischmann A. Vincent PA. Etgen AM. Effects of non-competitive NMDA receptor antagonists on reproductive and motor behaviors in female rats. Brain Research. 568(1-2): 138-146, 1991 Dec.
Pleim ET. Cailliau PJ. Weinstein MA. Etgen AM. Barfield RJ. Facilitation of receptive behavior in estrogen-primed female rats by the anti-progestin, RU 486. Hormones & Behavior. 24(3): 301-310, 1990 Sept.
Etgen AM. Intrahypothalamic implants of noradrenergic antagonists disrupt lordosis behavior in female rats. Physiology & Behavior. 48(1): 31-36, 1990 July
Fleischmann A. Makman MH. Etgen AM. Ovarian steroids increase veratridine-induced release of amino acid neurotransmitters in preoptic area synaptosomes. Brain Research. 507(1): 161-163, 1990 Jan.
Petitti N. Etgen AM. Alpha 1-adrenoceptor augmentation of beta-stimulated cAMP formation is enhanced by estrogen and reduced by progesterone in rat hypothalamic slices. Journal of Neuroscience. 10(8): 2842-2849, 1990 Aug.
Etgen AM. Fadem BH. Ontogeny of estrogen binding sites in the brain of gray short-tailed opossums (Monodelphis domestica). Brain Research.Developmental Brain Research. 49(1): 131-133, 1989 Sept.
Petitti N. Etgen AM. Progesterone depression of norepinephrine-stimulated cAMP accumulation in hypothalamic slices. Brain Research.Molecular Brain Research. 5(2): 109-119, 1989 Mar.
Vathy IU. Etgen AM. Barfield RJ. Actions of RU 38486 on progesterone facilitation and sequential inhibition of rat estrous behavior: correlation with neural progestin receptor levels. Hormones & Behavior. 23(1): 43-56, 1989 Mar.
Pleim ET. Brown TJ. MacLusky NJ. Etgen AM. Barfield RJ. Dilute estradiol implants and progestin receptor induction in the ventromedial nucleus of the hypothalamus: correlation with receptive behavior in female rats. Endocrinology. 124(4): 1807-1812, 1989 Apr.
Ng CM. Gerhardt GA. Friedemann M. Etgen AM. Rose GM. Sharpless NS. Gardner EL. The effects of delta 9-tetrahydrocannabinol on potassium-evoked release of dopamine in the rat caudate nucleus: an in vivo electrochemical and in vivo microdialysis study. Brain Research. 451(1-2): 59-68, 1988 June
Etgen AM. Robisch DM. Differential extraction of estradiol- and tamoxifen-receptor complexes from hypothalamic cell nuclei. Brain Research. 452(1-2): 1-10, 1988 June
Vathy I. Etgen AM. Ovarian steroids and hypothalamic norepinephrine release: studies using in vivo brain microdialysis. Life Sciences. 43(19): 1493-1499, 1988
Etgen AM. Fadem BH. Estrogen binding macromolecules in hypothalamus-preoptic area of male and female gray short-tailed opossums (Monodelphis domestica). General & Comparative Endocrinology. 66(3): 441-446, 1987 June
Etgen AM. Browning ET. Calcium dependence of vasoactive intestinal peptide-stimulated cyclic AMP accumulation in rat hippocampal slices. Journal of Neurochemistry. 49(1): 303-309, 1987 July
Etgen AM. Inhibition of estrous behavior in rats by intrahypothalamic application of agents that disrupt nuclear binding of estrogen-receptor complexes. Hormones & Behavior. 21(4): 528-535, 1987 Dec.
Etgen AM. Petitti N. Mediation of norepinephrine-stimulated cyclic AMP accumulation by adrenergic receptors in hypothalamic and preoptic area slices: effects of estradiol. Journal of Neurochemistry. 49(6): 1732-1739, 1987 Dec.
Glaser JH. Etgen AM. Barfield RJ. Temporal aspects of ventromedial hypothalamic progesterone action in the facilitation of estrous behavior in the female rat. Behavioral Neuroscience. 101(4): 534-545, 1987 Aug.
Vathy IU. Etgen AM. Barfield RJ. Actions of progestins on estrous behaviour in female rats. Physiology & Behavior. 40(5): 591-595, 1987
Etgen AM. Barfield RJ. Antagonism of female sexual behavior with intracerebral implants of antiprogestin RU 38486: correlation with binding to neural progestin receptors. Endocrinology. 119(4): 1610-1617, 1986 Oct.
Etgen AM. Petitti N. Norepinephrine-stimulated cyclic AMP accumulation in rat hypothalamic slices: effects of estrous cycle and ovarian steroids. Brain Research. 375(2): 385-390, 1986 June
Etgen AM. Shamamian P. Regulation of estrogen-stimulated lordosis behavior and hypothalamic progestin receptor induction by antiestrogens in female rats. Hormones & Behavior. 20(2): 166-180, 1986 June
Etgen AM. Effects of body weight, adrenal status, and estrogen priming on hypothalamic progestin receptors in male and female rats. Journal of Neuroscience. 5(9): 2439-2442, 1985 Sept.
Glaser JH. Etgen AM. Barfield RJ. Intrahypothalamic effects of progestin agonists on estrous behavior and progestin receptor binding. Physiology & Behavior. 34(6): 871-877, 1985 June
Vathy IU. Etgen AM. Barfield RJ. Effects of prenatal exposure to morphine on the development of sexual behavior in rats. Pharmacology, Biochemistry & Behavior. 22(2): 227-232, 1985 Feb.
Howard SB. Etgen AM. Barfield RJ. Antagonism of central estrogen action by intracerebral implants of tamoxifen. Hormones & Behavior. 18(3): 256-266, 1984 Sept.
Etgen AM. Progestin receptors and the activation of female reproductive behavior: a critical review. Hormones & Behavior. 18(4): 411-430, 1984 Dec.
Barfield RJ. Glaser JH. Rubin BS. Etgen AM. Behavioral effects of progestin in the brain. [Review] [63 refs]. Psychoneuroendocrinology. 9(3): 217-231, 1984
Vathy IU. Etgen AM. Rabii J. Barfield RJ. Effects of prenatal exposure to morphine sulfate on reproductive function of female rats. Pharmacology, Biochemistry & Behavior. 19(5): 777-780, 1983 Nov.
Etgen AM. Browning ET. Activators of cyclic adenosine 3':5'-monophosphate accumulation in rat hippocampal slices: action of vasoactive intestinal peptide (VIP). Journal of Neuroscience. 3(12): 2487-2493, 1983 Dec.
Etgen AM. 1-(o-chlorophenyl)-1-(p-chlorophenyl)2,2,2-trichloroethane: a probe for studying estrogen and progestin receptor mediation of female sexual behavior and neuroendocrine responses. Endocrinology. 111(5): 1498-1504, 1982 Nov.
Thomas DA. Barfield RJ. Etgen AM. Influence of androgen on the development of sexual behavior in rats. I. Time of administration and masculine copulatory responses, penile reflexes, and androgen receptors in females. Hormones & Behavior. 16(4): 443-454, 1982 Dec.
Etgen AM. Whalen RE. Kinetic analysis of estrogen and antiestrogen competition for hypothalamic cytosol estrogen receptors. Evidence for noncompetitive ligand-receptor interactions. Journal of Receptor Research. 2(5-6): 531-553, 1981 Aug.
Etgen AM. Estrogen induction of progestin receptors in the hypothalamus of male and female rats which differ in their ability to exhibit cyclic gonadotropin secretion and female sexual behavior. Biology of Reproduction. 25(2): 307-313, 1981 Sept.
Etgen AM. Differential effects of two estrogen antagonists on the development of masculine and feminine sexual behavior in hamsters. Hormones & Behavior. 15(3): 299-311, 1981 Sept.
Etgen AM. Martin M. Gilbert R. Lynch G. Characterization of corticosterone-induced protein synthesis in hippocampal slices. Journal of Neurochemistry. 35(3): 598-602, 1980 Sept.
Etgen AM. Antiestrogens: effects of tamoxifen, nafoxidine, and CI-628 on sexual behavior, cytoplasmic receptors, and nuclear binding of estrogen. Hormones & Behavior. 13(2): 97-112, 1979 Oct.
Etgen AM. Whalen RE. Musculinization and defeminization induced in female hamsters by neonatal treatment with estradiol, RU-2858, and nafoxidine. Hormones & Behavior. 12(3): 211-217, 1979 June
Etgen AM. Lee KS. Lynch G. Glucocorticoid modulation of specific protein metabolism in hippocampal slices maintained in vitro. Brain Research. 165(1): 37-45, 1979 Apr.
Etgen AM. Whalen RE. Dimethystilbestrol is not antiestrogenic for rat sexual behavior or gonadotropin secretion. Biology of Reproduction. 19(2): 454-458, 1978 Sept.
Whalen RE. Etgen AM. Masculinization and defeminization induced in female hamsters by neonatal treatment with estradiol benzoate and RU-2858. Hormones & Behavior. 10(2): 170-177, 1978 Apr.