This research will clarify the influence of gonadal hormones on neurotransmitter release in a key site for the control of male sexual behavior. The medial preoptic area (MPOA) is essential for males' copulation in virtually all vertebrate species. MPOA dopamine (DA) facilitates male rats' sexual motivation, copulatory motor patterns, and genital reflexes.
Aim 1 will investigate the factors that regulate DA release in the MPOA. Castrates have more intracellular, but less extracellular, DA in the MPOA than do intact males. A decrease in the soluble gas nitric oxide (NO) may contribute to the failure of castrates to release DA. In castrates, we will test the effects of the two major metabolites of testosterone, applied to the MPOA, on MPOA DA release and on the enzyme that synthesizes NO. We will also study the effects of sexual experience on DA release and behavior, determine the second messenger by which NO stimulates DA release, and study the interactions among DA, glutamate, and GABA in the MPOA.
Aim 2 will study the role of a major input to the MPOA. We will test whether lesions or stimulation of the medial amygdala influences DA or amino acid release in the MPOA.
Aim 3 will investigate the ability of DA to activate steroid receptors in a ligand-independent fashion, and thereby facilitate copulation, in male rats, as it does in females. We will test whether antisense oligonucleotides to progesterone, androgen, or estrogen receptors block the facilitative effects of a DA agonist release in the anterior lateral hypothalamus (LHA) at the time of ejaculation; a selective serotonin reuptake inhibitor (SSRI) injected there delays the onset of copulation and inhibits ejaculation. We will determine the receptor subtype(s) that mediate the inhibitory effects of 5-HT in the LHA. We will also measure basal and female-stimulated levels of 5-HT and DA in the LHA and the mesolimbic system after chronic treatment with an SSRI. SSRI antidepressants frequently impair sexual function in humans. This research should lead to better treatment for primary and SSRI-induced sexual dysfunctions. The teaching reduction provided by this award will allow me to learn to synthesize and use antisense oligonucleotides and to expand our use of microdialysis to detect amino acid neurotransmitters and of electrical stimulation to study functional circuits. It will also allow me to become more active in national and international scientific organizations.
|Vigdorchik, Anna V; Parrish, Bradley P; Lagoda, Gwen A et al. (2012) An NMDA antagonist in the MPOA impairs copulation and stimulus sensitization in male rats. Behav Neurosci 126:186-95|
|Hull, Elaine M (2011) Sex, drugs and gluttony: how the brain controls motivated behaviors. Physiol Behav 104:173-7|
|Sato, Satoru M; Wersinger, Scott R; Hull, Elaine 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. Horm Behav 52:177-82|
|Hull, Elaine M; Dominguez, Juan M (2007) Sexual behavior in male rodents. Horm Behav 52:45-55|
|Dominguez, Juan M; Gil, Mario; Hull, Elaine M (2006) Preoptic glutamate facilitates male sexual behavior. J Neurosci 26:1699-703|
|Hull, Elaine M; Dominguez, Juan M (2006) Getting his act together: roles of glutamate, nitric oxide, and dopamine in the medial preoptic area. Brain Res 1126:66-75|
|Dominguez, Juan M; Brann, Jessica H; Gil, Mario et al. (2006) Sexual experience increases nitric oxide synthase in the medial preoptic area of male rats. Behav Neurosci 120:1389-94|
|Dominguez, Juan M; Hull, Elaine M (2005) Dopamine, the medial preoptic area, and male sexual behavior. Physiol Behav 86:356-68|
|Sato, Satoru; Braham, Claudean S; Putnam, Susan K et al. (2005) Neuronal nitric oxide synthase and gonadal steroid interaction in the MPOA of male rats: co-localization and testosterone-induced restoration of copulation and nNOS-immunoreactivity. Brain Res 1043:205-13|
|Muschamp, John W; Regina, Meredith J; Hull, Elaine M et al. (2004) Lysergic acid diethylamide and [-]-2,5-dimethoxy-4-methylamphetamine increase extracellular glutamate in rat prefrontal cortex. Brain Res 1023:134-40|
Showing the most recent 10 out of 14 publications