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. 2025 Sep;242(9):2097-2110.
doi: 10.1007/s00213-025-06786-y. Epub 2025 Apr 15.

Disruptive effects of d-amphetamine on conditioned sexual inhibition in the male rat

Katuschia Germé  1 , Dhillon Persad  1 , Justine Petit-Robinson  1 , Shimon Amir  1 , James G Pfaus  2   3   4
Affiliations

Disruptive effects of d-amphetamine on conditioned sexual inhibition in the male rat

Katuschia Germé et al. Psychopharmacology (Berl). 2025 Sep.

Abstract

Rationale: Male rats trained to associate a neutral odor (almond) with nonreceptive females during their initial sexual experiences develop a conditioned sexual inhibition (CSI) toward the female bearing the olfactory cue when given a choice in a final copulatory preference test between two receptive females (one unscented and one scented) in an open field. We have previously shown that this CSI can be abolished by acute alcohol before the final copulatory preference test.

Objective: To examine whether acute treatment with d-amphetamine could also disrupt CSI.

Methods: Male rats received 20 alternating conditioning sessions with an unscented receptive female or an almond-scented non-receptive female. Forty minutes prior to the copulatory preference test with two receptive females, one unscented and the other scented (almond extract), males were injected with saline or one of three doses of d-amphetamine (d- 0.5, 1.0, or 2.0 mg/kg). After two reconditioning trials, males were injected with d-amp or saline and exposed to the olfactory cue alone for 1 h. Brains were fixed and processed for immunohistochemical analysis of Fos protein as a marker of neuronal activation. Fos expression was assessed in several brain regions involved in male sexual behavior.

Results: Saline-treated males displayed inhibition of copulatory behavior directed toward the scented female. In contrast, and regardless of the dose, males treated with d-amp prior to the final test copulated with both scented and unscented females, indicating that d-amp disrupted the CSI. Exposure to d-amphetamine and the odor alone induced a differential pattern of Fos expression in several brain areas involved in the expression and/or the regulation of male sexual behavior.

Conclusions: As observed previously with alcohol, a low dose of d-amphetamine disrupted the display of a CSI by acting on brain regions mediating sexual behavior.

Keywords: Conditioned sexual inhibition; D-amphetamine; Fos immunoreactivity; Sexual behavior.

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Conflict of interest statement

Declarations. Ethical approval: The authors declare that all animal procedures conformed to the guidelines of the Canadian Council for Animal Care. All procedures were approved by the Concordia University Animal Research Ethics Committee (ACC-30000300). Consent to participate: Not applicable. Consent to publish: All authors have agreed to publish. Competing interests: JGP is a consultant for FirmTech (USA), Kadence Bio Ltd. (UK), Lioness/Smart Bod Inc. (USA), Ovoca Bio/IVIX Corp. (Ireland), Reunion Neuroscience (Canada), and Vella Bioscience (USA). There are no conflicts of interest with the present study.

References

    1. Ǻgmo A, Fernández H (1989) Dopamine and sexual behavior in the male rat: a Reevaluation. J Neural Transm 77:21–37. https://doi.org/10.1007/BF01255816 - DOI
    1. Ǻgmo A, Villalpando A (1995) Central nervous stimulants facilitate sexual behavior in male rats with medial prefrontal cortex lesions. Brain Res 696:187–193. https://doi.org/10.1016/0006-8993(95)00853-i - DOI
    1. Baum MJ, Everitt BJ (1992) Increased expression of c-fos in the medial preoptic area after mating in male rats: role of afferent inputs from the medial amygdala and midbrain central tegmental field. Neuroscience 50:627–646. https://doi.org/10.1016/0306-4522(92)90452-8 - DOI
    1. Bekkers JM, Suzuki N (2013) Neurons and circuits for odor processing in the piriform cortex. Trends Neurosci 36:429–438. https://doi.org/10.1016/j.tins.2013.04.005 - DOI
    1. Berridge KC, Robinson TE (1998) What is the role of dopamine in reward: hedonic impact, reward learning, or incentive salience? Brain Res Brain Res Rev 28:309–369. https://doi.org/10.1016/s0165-0173(98)00019-8 - DOI

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