Fluoxetine differentially suppresses sucrose solution consumption in free-fed and food-deprived rats--reversal by amantadine.

Background: Clinical use of fluoxetine and similar medications is often associated with appetite suppression and weight loss that may warrant drug discontinuation. It is unclear, however, if fluoxetine-induced consummatory suppression may be influenced by factors such as dietary status and if appetite suppressant effects of fluoxetine may be pharmacologically attenuated.

Material/methods: Fluoxetine (0.

Conditioned taste aversion induced by fluoxetine.

The present study assessed the ability of the serotonin reuptake inhibitor fluoxetine (FLX) and lithium chloride (LiCl) to induce conditioned taste aversion (CTA) to a novel 20% sucrose solution. FLX (2, 5, or 8 mg/kg) or LiCl (10 mg/kg) was administered 30 min after an initial exposure to the solution. A single-bottle test of CTA 24 h after the initial exposure indicated that rats that received FLX, at any dose, or LiCl consumed significantly less solution than did those that received a vehicle treatment following the initial exposure.

Monoaminergic influences on temporal patterning of sexual behavior in male rats.

We evaluated the effects of the serotonin (5-HT) presynaptic uptake blocker fluoxetine (FLX) and the dopamine (DA)/noradrenaline (NE) releaser amantadine (AMA), separately and in combination, on the temporal patterning of male rat sexual behavior. FLX alone increased intermount-bout intervals, time-outs, grooming time, ejaculation latency, number of mounts per mount bout, and number of mount bouts per ejaculation. AMA alone had the opposite effect on these measures.

Fluoxetine-induced inhibition of male rat copulatory behavior: modification by lesions of the nucleus paragigantocellularis.

In Experiment 1, the 5-HT uptake blocker fluoxetine (FLX; 20 mg/kg) reduced the proportion of sexually experienced male rats displaying ejaculations. Among those animals that did ejaculate there was an increase in intromission frequency (IF), ejaculation latency (EL), and postejaculatory interval (PEI) and a reduction in copulatory efficiency (CE) during the final copulatory sequence prior to sexual exhaustion. In Experiment 2, we found similar inhibitory effects of FLX as well as facilitating effects of lesions of the nucleus paragigantocellularis (PGi) on male rat copulatory behavior.

Lesions of the nucleus paragigantocellularis: effects on mating behavior in male rats.

We evaluated the effects of bilateral radio-frequency lesions of the paragigantocellular (PGi) reticular nucleus in the ventral medulla on male rat copulatory behavior. In Experiment 1, sexually naive male rats with such lesions were more likely than sham-operated controls to copulate to ejaculation during their first exposure to an estrous female. Additionally, among the rats that copulated to ejaculation, those with lesions demonstrated a reduction in mount frequency (MF), intromission frequency (IF), and ejaculation latency (EL), and an increase in copulatory efficiency (CE).