Research Interest

My research program investigates the neuroendocrine control of male rat sexual behavior. We have shown that dopamine is released in the medial preoptic area (MPOA) as soon as a male rat encounters a receptive female; release is further increased during copulation. Stimulation of dopamine receptors in the MPOA controls genital reflexes and sexual motivation. This brain area is essential for male sexual behavior in all vertebrate species that have been studied, from fish through humans. Testosterone promotes copulation, in part, by up-regulating nitric oxide synthase in the MPOA; the resultant production of nitric oxide increases both basal and female-stimulated dopamine release. We have also shown that serotonin is released in the anterior lateral hypothalamus at the time of ejaculation and contributes to the postejaculatory sexual quiescence, in part by decreasing mesolimbic dopamine release. Recent research centers on the roles of dopamine and glutamate in the increase in sexual proficiency due to sexual experience. Similar mechanisms may underlie other forms of memory and drug addiction. Finally, we are interested in how the circuitry underlying sexual behavior is integrated with that subserving other motivated behaviors.

Publications

Recent Research Articles

Muschamp, J.W. & Hull, E.M. (2007) Melanin concentrating hormone and estrogen receptor-α are coextensive but not coexpressed in cells of male rat hypothalamus. Neuroscience Letters, 427: 123-126.
Muschamp, J.W., Dominguez, J.M., Sato, S.M., Shen, R-Y, & Hull, E.M. (2007) A Role for Hypocretin (Orexin) in Male Sexual Behavior, The Journal of Neuroscience, 27: 2837-2845.
Sato, S.M., Wersinger, S.R., & Hull, E.M. (2007) The effects of nitric oxide-cGMP pathway stimulation on dopamine in the medial preoptic area and copulation in DHT-treated castrated male rats. Hormones and Behavior, 52: 177-182.
Dominguez, J.M., Brann, J.H., Gil, M., & Hull, E.M. (2006) Sexual experience increases nitric oxide synthase in the medial preoptic area of male rats. Behavioral Neuroscience, 120: 1389-1394.
Dominguez, J. M., Gil, M, & Hull, E.M. (2006) Preoptic glutamate facilitates male sexual behavior. The Journal of Neuroscience, 26: 1699-1703.
Sato, S. & Hull, E.M.(2006) The nitric oxide-cGMP pathway regulates dopamine efflux in the medial preoptic area and copulation in male rats, Neuroscience, 139: 417-428.
Sato, S., Braham, C.S., Putnam, S.K., & Hull, E.M. (2005) Neuronal nitric oxide synthase (nNOS) and gonadal steroids in the MPOA of male rats: Co-localization of nNOS with steroid receptors and testosterone- induced restoration of copulation and nNOS-immunoreactivity. Brain Research, 1043: 205-213.
Putnam, S.K., Sato, S., & Hull, E.M. (2005) Hormonal maintenance of copulation in castrates: Association with intracellular dopamine and with nitric oxide synthase in MPOA. Hormones and Behavior, 47: 513- 522.
Hull, E.M. Muschamp, J. W., & Sato, S. (2004) Dopamine and serotonin: Influences on male sexual behavior. In special issue of Physiology & Behavior on Male Sexual Behavior, Lique Coolen and E.M. Hull, Co- Editors, 83:291-308.
Lagoda, G., Vigdorchik, A., Muschamp, J.W., & Hull, E.M. (2004) A nitric oxide synthase inhibitor in the MPOA inhibits copulation and stimulus sensitization in male rats. Behavioral Neuroscience, 118:1317–1323.
Muschamp, J.W., Regina, M. J., Hull, E.M., Winter, J.C., & Rabin, R.A. (2004) Lysergic acid diethylamide (LSD) and [-]-2,5-dimethoxy-4- methylamphetamine (DOM) increase extracellular glutamate in rat prefrontal cortex. Brain Research, 1023:134-140.
Dominguez, J.M, Muschamp, J.W., Schmich, J.M., & Hull, E.M. (2004) Glutamate-evoked dopamine release in the medial preoptic area is mediated by nitric oxide: Implications for male rat sexual behavior. Neuroscience, 125:203-210.
Putnam, S.K., Sato, S., & Hull, E.M. (2003) Hormonal maintenance of copulation in castrates: Association with extracellular dopamine in MPOA. Hormones and Behavior, 44:419-426.
Lonstein, J.S., Dominguez, J.M., Putnam, S.K., DeVries, G.J., & Hull, E.M. (2003) Intracellular preoptic area dopamine and serotonin during pregnancy and lactation in rats: Possible role in maternal behavior. Brain Research, 970:149-158.
Dominguez, J.M., & Hull, E.M. (2003) The medial amygdala regulates mating- induced dopamine release in the medial preoptic area. Annals, New York Academy of Sciences, 985:515-518.
Powell, W., Dominguez, J.M., & Hull, E.M. (2003) An NMDA antagonist blocks the experience-induced enhancement of male sexual behavior. Behavioral Neuroscience, 117:69-75.
Dominguez, J.M. & Hull, E.M. (2001) Stimulation of the medial amygdala enhances medial preoptic dopamine release: Implications for male rat sexual behavior. Brain Research, 917:225-229.
Putnam, S.K., Du, J., & Hull, E.M. (2001) Testosterone restoration of copulation and medial preoptic dopamine release in castrated male rats: 2-, 5-, and 10-day treatments. Hormones and Behavior, 39: 216- 224.
Dominguez, J., Riolo, J.V., Xu, Z. & Hull, E.M. (2001) Regulation by the medial amygdala of copulation and medial preoptic dopamine release. Journal of Neuroscience, 21:349-355.
Matuszewich, L., Lorrain, D. S., & Hull, E. M. (2000) Dopamine alterations in the medial preoptic area of female rats in response to hormonal manipulation and sexual activity. Behavioral Neuroscience, 114:772- 782.

Recent Review Articles

Hull, E.M. & Dominguez, J.M. (2007) Hormonal control of male sexual behavior in rodents. Invited review for a special issue of Hormones and Behavior on Reproductive Behavior in Farm and Laboratory Animals, edited by Gabriella Gonzalez-Mariscal and Charles Rosseli, 52: 45-55.
Hull, E.M. & Dominguez, J.M. (2006) Getting his act together: Roles of glutamate, nitric oxide, and dopamine in the medial preoptic area. Invited review for a special issue of Brain Research on Sex, Genes, and Steroids, edited by Jill Becker, 1126: 66-75.
Dominguez, J.M. & Hull, E.M. (2005) Dopamine, the medial preoptic area, and male sexual behavior. Physiology & Behavior, 86: 356-368.
Hull, E.M. Muschamp, J. W., & Sato, S. (2004) Dopamine and serotonin: Influences on male sexual behavior. In special issue of Physiology & Behavior on Male Sexual Behavior, Lique Coolen and E.M. Hull, Co-Editors, 83:291-308.
Meston CM. Hull E. Levin RJ. Sipski M. (2004) Disorders of orgasm in women. Journal of Sexual Medicine. 1: 66-68.

Selected Book Chapters

Hull, E.M. & Rodriguez-Manzo, G. (in press) Male Sexual Behavior. In Hormones, Brain and Behavior, Second Edition, Donald Pfaff, Editor-in- Chief, Elsevier Press.
Hull, E.M., Dominguez, J.M., & Muschamp, J.M. (2007) The neurochemistry of male sexual behavior. In Behavioral Neuroendocrinology, Neurochemistry, and Molecular Neurobiology, Jeffrey Blaustein, editor, one of a 24-volume series in Handbook of Neurochemistry and Molecular Neurobiology, Abel Lajtha, Editor-in-Chief. Springer Verlag, pp. 37- 94.
Hull, E.M., Wood, R.I., & McKenna, K. E. (2006) The neurobiology of male sexual behavior. In: The Physiology of Reproduction, 3rd Edition J. Neill, Editor in Chief, Donald Pfaff, Section Editor, Elsevier Press, pp. 1729-1824.
Meston, C. M., Levin, R., Sipski, M. L., Hull, E. M., & Heiman, J. R. (2005). Women's Orgasm. In: J. R. Heiman, C. M. Davis, & S. L. Davis (Eds.), Annual review of sex research: An integrative and interdisciplinary review (pp. 173-257). Mason City, IA: The Society for the Scientific Study of Sexuality.
Meston, C.M., Hull, E.M., Levin, R.J., Sipski, M.L. (2004) Women’s orgasm. In: Sexual Medicine: Sexual Dysfunctions in Men and Women. T. F. Lue, R. Basson, R. Rosen, F. Giuliano, S. Khoury, F. Montorsi, Eds. Health Publications, Paris, France. pp. 783-850.
Hull, E.M. & Dominguez, J.M. (2003) Sex Behavior. In: Comprehensive Handbook of Psychology, Vol. 3, Biological Psychology, R. J. Nelson and M. Gallagher, Eds. Wiley & Sons, pp. 321-353.
Hull, E.M., Meisel, R.L., & Sachs, B.D. (2002) Male sexual behavior. In: Hormones, Brain and Behavior, (a 5 vol. set) D.W. Pfaff, A.P. Arnold, A.M. Etgen, S.E. Fahrbach, & R.T. Rubin, Eds. Academic Press, pp. 3- 137.
Hendry, B., Althof, S., Benson, G.S., Haensel, S.M., Hull, E.M., Kihara, K. & Opsomer, R.J. (2000) Male orgasmic and ejaculatory disorders. In Erectile Dysfunction, A. Jardin, G. Wagner, S. Koury, & F. Giuliano, H. Padma-Nathan, R. Rosen, Eds. World Health Organization Publication, pp. 477-506.