雄性線蟲整合幼年與成年期的感官經驗調控交配行為

Abstract

早期經驗塑造神經系統，從而完善成年動物的行為表現。已有研究表明，在一個關鍵時期內的早期經驗所產生的感官印記會調節後期發育階段的行為；然而，目前還不清楚動物是否能整合多種感官經驗來調節行為。在這裡，我們發現秀麗隱桿線蟲雄性整合了幼蟲和成蟲對雌雄同體專一性費洛蒙的感官經驗，從而完善了交配行為的表現。在幼蟲和成蟲階段，性別專一性費洛蒙的存在顯著縮短了雄性接觸雌雄同體和伸出雌雄同體骨針的時間。有趣的是，我們發現雄性在幼蟲和成蟲階段通過兩個階段的時間整合費洛蒙信號。早期短暫暴露於費洛蒙是神經調節效應的先決條件，但這還不夠。相反，早期接觸費洛蒙的成年雄性只有在富含費洛蒙的環境中才會表現出行為上的改進。因此，我們的研究結果揭示了一種出乎意料的複雜學習方案，即在整合了多種感官經驗的情況下，雄性秀麗隱桿線蟲的行為表現會得到改進。

Early experience sculpts the nervous system to refine behavioral performance of adults. It has been shown that sensory imprinting by early experience within a critical period modulates the behaviors in later developmental stages; however, it is current unclear whether animals can integrate multiple sensory experiences for behavioral modulations. Here we show that C. elegans males integrate larvae and adult sensory experience of hermaphrodite-specific pheromones to refine the performance of stereotyped mating behaviors. The presence of sex-specific pheromones across early and adult stages remarkably reduces the time for males to contact hermaphrodites and protract spicules. Interestingly, we find that males integrate pheromonal signaling through two windows in larva and adult stages. Early exposure to pheromones for a minimal time is prerequisite but not sufficient to display the neuromodulatory effects. Instead, adult males with early exposure of pheromones show the behavioral refinements only in the environment enriched with pheromones. Our results thus reveal an unexpected complex learning scheme to refine the behavioral outputs integrating multiple sensory experiences in C. elegans males.