Lack of opioid or dopaminergic effects on unconditioned sexual incentive motivation in male rats.

Abstract

The effects of dopaminergic and opioidergic drugs on sexual incentive motivation were evaluated in sexually inexperienced male rats subjected to a choice procedure. Various parameters of ambulatory activity were recorded as well. Two drugs stimulating dopaminergic neurotransmission, amphetamine and apomorphine, failed to affect sexual incentive motivation, although ambulatory activity was enhanced by amphetamine. The dopamine antagonist cis(Z)-flupenthixol reduced sexual incentive motivation, but only at a dose that severely disrupted motor function. Morphine had marginal effects on sexual motivation but reduced ambulatory activity. These effects were not reduced by a peripheral opioid antagonist, methylnaloxone. Loperamide, a peripheral opioid agonist, reduced sexual motivation through an opioid-independent action. Naloxone was ineffective. Neither dopamine nor opioids seem to be important for sexual incentive motivation.

Excitotoxic lesions of the tegmental pedunculopontine nucleus impair copulation in naive male rats and block the rewarding effects of copulation in experienced male rats

“…The finding that lesioned, sexually naive males that failed to copulate also failed to display receptive female preference is consistent with previous studies demonstrating an effect of sexual experience on the development of preferential approach to a receptive female (for a review see Taylor & Dewsbury, 1990). However, other studies have shown preferences for receptive females in sexually naive males (Agmo, 2003a,b), suggesting that TPP lesions or TPP lesions with exposure to receptive females in naive males interferes with these unconditioned preferences. Collectively, our findings demonstrate that the effects of TPP lesions in sexually naive males involve a deficit in the acquisition of specific aspects of sexual behaviour.…”

“…, 2002). Consistent with this hypothesis, sexual stimuli have high motivational value to both sexually naive and sexually experienced males (Agmo, 2003a,b) and reinforcement and reward are disrupted in both conditions. However, this hypothesis does not account for the TPP independence of drug reward processes in the drug‐dependent and deprived state (Bechara et al ., 1992) when drug motivation and responding are elevated (Dai et al.…”

Effects of methamphetamine on sexual performance and compulsive sex behavior in male rats

“…0.5 and 1 mg/kg) or amfonelic acid (0.25 and 0.5 mg/kg; i.p.) caused the facilitation of sexual performance in sexually naïve male rats (Agmo and Berenfeld 1990), but did not affect sexual motivation (Agmo 2003). Moreover, amfonelic acid administration resulted in a significantly increased frequency of sniffing and rearing behavior while behaviors associated with sexual behavior (female pursuit and mounting attempts) were not altered (Agmo and Berenfeld 1990).…”

The exposure to Trichilia catigua (catuaba) crude extract impairs fertility of adult female rats but does not cause reproductive damage to male offspring

“…The same animals evaluated for copulatory behavior were submitted to the sexual incentive motivation test (Agmo, 2003). In this test, a rectangular arena with 50  50  100 cm 3 (height  width  length) that presents two openings that communicate with two small arenas with 25 cm 2 was used.…”