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Updated: Feb 16, 2026
Assessment of Sexual Behavior of Male Mice
Published on: March 5, 2020
Revisiting medial preoptic area plasticity induced in male mice by sexual experience
Arnaud Jean1, Pauline Bonnet1, Philippe Liere2
1Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neuroscience Paris - Seine; Institut de Biologie Paris Seine, 75005, Paris, France.
Abstract:
Sexual experience in male rodents, induced by a first exposure to a receptive female, improves efficiency of following copulations. In mice, the mechanisms supporting this improvement are poorly understood. We characterized molecular modifications of the mouse hypothalamic medial preoptic area (mPOA), the main integrative structure for male sexual behaviour, after a single mating event. This paradigm induced long-lasting behavioural improvements and mPOA morphological changes, evidenced by dendritic spine maturation and an increase in the acetylated and tri-methylated forms of histone H3. Ejaculation affected testosterone, progesterone and corticosterone levels in both naive and experienced mice, but sexual experience did not modify basal plasma or hypothalamic levels of steroids. In contrast to studies carried out in rats, no changes were observed, either in the nitrergic system, or in sex steroid receptor levels. However, levels of glutamate- and calcium-associated proteins, including PSD-95, calbindin and the GluN1 subunit of the NMDA receptor, were increased in sexually experienced male mice. The Iba-1 microglial marker was up-regulated in these animals suggesting multicellular interactions induced within the mPOA by sexual experience. In conclusion, plasticity mechanisms induced by sexual experience differ between rat and mouse, even if in both cases they converge to potentiation of the mPOA network.
Insights
Male mice show lasting behavioral improvements after mating, linked to molecular changes in the medial preoptic area (mPOA). Sexual experience enhances neuronal plasticity and glial activation within the mPOA.
Area of Science:
- Neuroscience
- Behavioral Biology
- Molecular Biology
Background:
- Sexual experience enhances male sexual behavior efficiency in rodents.
- Mechanisms underlying this improvement in mice are not well understood.
- The medial preoptic area (mPOA) is crucial for integrating male sexual behavior.
Purpose of the Study:
- To characterize molecular and morphological changes in the mouse mPOA following a single mating event.
- To understand the neurobiological basis of enhanced sexual performance after initial experience.
- To compare plasticity mechanisms in mice with those previously observed in rats.
Main Methods:
- Analysis of molecular modifications in the mPOA of male mice after mating.
- Assessment of behavioral improvements and morphological changes (dendritic spines, histone modifications).
- Measurement of plasma and hypothalamic steroid levels, receptor levels, and protein expression (glutamate, calcium, NMDA receptor, microglial markers).
Main Results:
- A single mating event induced long-lasting behavioral improvements and mPOA dendritic spine maturation.
- Histone H3 acetylation and tri-methylation increased in the mPOA.
- Levels of glutamate- and calcium-associated proteins (PSD-95, calbindin, GluN1) and the microglial marker Iba-1 were elevated in experienced mice.
- Unlike rats, no changes were observed in the nitrergic system or sex steroid receptor levels.
Conclusions:
- Sexual experience in male mice induces significant molecular and morphological plasticity in the mPOA.
- These changes involve neuronal and glial elements, suggesting multicellular interactions.
- Plasticity mechanisms differ between mice and rats but converge on mPOA network potentiation.
