Martínez-Ricós Joana, Agustín-Pavón Carmen, Lanuza Enrique, Martínez-García Fernando
Departament de Biologia Funcional i Antropologia Física, Facultat de Ciències Biològiques, Universitat de València, C/ Dr Moliner, 50, ES-46100, Burjassot, València, Spain.
Chem Senses. 2007 Feb;32(2):139-48. doi: 10.1093/chemse/bjl039. Epub 2006 Nov 3.
In rodents, social and reproductive behaviors critically depend on chemical signals, including sexual pheromones that have been suggested (but not demonstrated) to be rewarding. In this work, we analyze this issue by studying the chemoinvestigatory behavior of adult female mice (without experience with male-derived chemicals) toward 1) the synthetic odorant citralva, 2) bedding soiled by different conspecifics (females, males, and castrated males), and 3) volatiles derived from bedding soiled by males and castrated males (confronted in 2-choice tests). We also study whether these chemical signals are able to induce conditioned place preference, a reliable test for rewarding properties of stimuli. The results show that involatile, male-derived chemicals elicit an intense and sustained chemoinvestigation and, more importantly, are the only tested chemical signals that induce conditioned place preference. In contrast, volatile, male-derived chemicals are not significantly chemoinvestigated. Bedding soiled by castrated males induces a transient chemoinvestigation, likely directed to steroid-independent, biologically relevant chemical signals, whereas the intense chemoinvestigation of female-soiled bedding shows a slow habituation. Finally, females did not explore significantly citralva-odorized bedding. The present work constitutes the first demonstration of the unconditioned reinforcing properties of involatile (likely detected by the vomeronasal organ) steroid-dependent chemical signals in mammals.
在啮齿动物中，社交和生殖行为严重依赖化学信号，包括那些被认为（但尚未证实）具有奖赏作用的性信息素。在这项研究中，我们通过研究成年雌性小鼠（未接触过雄性来源化学物质）对以下物质的化学探究行为来分析这个问题：1）合成气味物质柠檬醛；2）被不同同种个体（雌性、雄性和去势雄性）弄脏的垫料；3）来自被雄性和去势雄性弄脏的垫料的挥发物（在二选一测试中进行对比）。我们还研究了这些化学信号是否能够诱导条件性位置偏爱，这是一种用于测试刺激奖赏特性的可靠方法。结果表明，不挥发的、雄性来源的化学物质会引发强烈且持续的化学探究，更重要的是，它们是唯一能诱导条件性位置偏爱的测试化学信号。相比之下，挥发性的、雄性来源的化学物质未引发显著的化学探究。被去势雄性弄脏的垫料会引发短暂的化学探究，可能针对不依赖类固醇的、具有生物学相关性的化学信号，而对被雌性弄脏的垫料的强烈化学探究则表现出缓慢的习惯化。最后，雌性小鼠对柠檬醛气味的垫料没有进行显著探索。本研究首次证明了哺乳动物中不挥发的（可能由犁鼻器检测到）、依赖类固醇的化学信号具有非条件强化特性。
