Dopaminergic control of male sex behavior in rats: Effects of an intracerebrally-infused agonist

Pharmacological analysis of male rat sexual behavior

“…However, the reported correlation between striatal DA levels and other copulatory parameters following electrolytic lesions of the substantia mgra [49] (i.e., depletion of strlatal DA levels was correlated with prolonged mount and ejaculation latencles), suggests that the stnatal DA system may contribute to the regulation of several aspects of copulatory behavior On the other hand, the effects of striatal DA depletion may be indicative of a general reduction In responsiveness to environmental stimuh, rather than a specific effect on copulatory behavior, since similar lesions of the mgrostriatal tract have been shown to suppress ingestive behaviors [228], intracranial self-stimulation [16], and active avoidance [66]. In hne with this suggestion, we have found that microinjectlons of apomorphine directly into the caudate nucleus had no effect on copulation [121].…”

“…These findings suggest a role for the mesolimbic DA system in the regulation of male copulatory behavior. Some support for this role was provided by our finding that microinjections of apomorphine into the nucleus accumbens produced a doserelated decrease in intromission latency; however, this effect was of marginal statistical sigmficance (p=0.058) [121].…”

“…(3-(3-hydroxyphenyl)-N-n-propylplperldme, 6-OHDA, 6-hydroxydopamme ~Followmg intra-MPOA rejection of 6-OHDA, see text for discussion ZPreferentml DA neurotoxm ff apphed w~th a noradrenerg~c reuptake blocker *Results have been attributed to an increase m 5-HT utthzat,on, see text for detads havlor or of those ejaculating (e.g., [139,140]). It sometimes refers to an increase in the number of ejaculations within a given time period (e.g., [121]), or before sexual satiation is reached. It may also refer to an increase in copulatory rate or in intromission ratlo.…”

Chemosensory Cues are Essential for Mating-Induced Dopamine Release in MPOA of Male Syrian Hamsters

“…Treatment with DA receptor antagonists into MPOA (Warner et al, 1991) or lesions of MPOA DA neurons and terminals with 6-hydroxydopamine (Bazzett et al, 1992;Dhawan et al, 1998) impair copulation in male rats. Conversely, stimulation of DA receptors in MPOA with the DA agonist, apomorphine, enhances the rate of copulation in male rats (Hull et al, 1986). Likewise, apomorphine can overcome mating deficits in castrated rats (Scaletta and Hull, 1990).…”

“…In males of most species, lesions of MPOA severely impair male sex behavior (Hull et al, 2002). Neurotoxic lesions of MPOA DA neurons with 6-hydroxydopamine impaired copulation as well (Bazzett et al, 1992;Dhawan et al, 1998) Moreover, copulation in male rats is stimulated by DA agonists in MPOA (Hull et al, 1986), and inhibited with DA antagonists (Warner et al, 1991). Sexual motivation, measured as choice of a female in an X-maze, is also inhibited by DA antagonists (Warner et al, 1991;Moses et al, 1995).…”