INRA, UR1197 Neurobiologie de l'Olfaction et Modélisation en Imagerie, F-78352 Jouy-en-Josas, France.
Physiol Behav. 2013 Aug 15;120:150-5. doi: 10.1016/j.physbeh.2013.07.012. Epub 2013 Jul 31.
Sexually experienced male rats display penile erections when exposed to faeces from mammalian females in oestrus (Rampin et al., Behav Brain Res, 172:169, 2006), suggesting that specific odours indicate female receptiveness across species. However, it is unknown to what extent the sexual response observed results from an odorous conditioning acquired during sexual experience. We tested the behavioural response of male Brown Norway rats both when sexually naïve and experienced to four odours, including oestrous rat faeces and 6-methyl-5-hepten-2-one (methylheptenone; a molecule found in higher concentrations during oestrus in female rats, foxes and horses). Odour had a significant effect on the sexual response of the naïve rats, with oestrus faeces provoking significantly more erections than herb odour, and with methylheptenone and di-oestrus faeces being intermediate. This indicates that sexually naïve male rats have an unconditioned ability to detect oestrous mediated via odour. After gaining sexual experience, the response to methylheptenone, di- and oestrus faeces was significantly higher than that observed with herb odour. These results strongly suggest that methylheptenone is part of the odorous bouquet of oestrus and contributes to the olfactory determination of female receptiveness.
有过性经验的雄性大鼠在接触处于发情期的哺乳动物雌性的粪便时会出现阴茎勃起（Rampin 等人，《行为脑研究》，172：169，2006），这表明特定的气味可以在不同物种之间指示雌性的接受度。然而，目前还不清楚观察到的性反应在多大程度上是由性经验过程中获得的气味条件作用引起的。我们测试了雄性褐家鼠在性经验丰富和性经验不足两种情况下对四种气味的行为反应，包括发情期大鼠的粪便和 6-甲基-5-庚烯-2-酮（甲基庚烯酮；一种在雌性大鼠、狐狸和马发情期浓度较高的分子）。气味对未经验的大鼠的性反应有显著影响，发情期粪便引起的勃起明显多于草药气味，而甲基庚烯酮和间情期粪便则处于中间水平。这表明，性经验不足的雄性大鼠具有通过气味检测发情的未条件能力。获得性经验后，对甲基庚烯酮、间情期和发情期粪便的反应明显高于对草药气味的反应。这些结果强烈表明，甲基庚烯酮是发情期气味组合的一部分，有助于嗅觉确定雌性接受度。
