Yan Zhenzhen, Cheng Xinran, Li Yuansong, Su Zexiong, Zhou Yiwei, Liu Jie
Neuroscience Program, Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia.
Front Mol Neurosci. 2022 Jan 31;14:780396. doi: 10.3389/fnmol.2021.780396. eCollection 2021.
Sexually dimorphic differentiation of sex-shared behaviors is observed across the animal world, but the underlying neurobiological mechanisms are not fully understood. Here we report sexual dimorphism in neurotransmitter release at the neuromuscular junctions (NMJs) of adult . Studying worm locomotion confirms sex differences in spontaneous locomotion of adult animals, and quantitative fluorescence analysis shows that excitatory cholinergic synapses, but not inhibitory GABAergic synapses exhibit the adult-specific difference in synaptic vesicles between males and hermaphrodites. Electrophysiological recording from the NMJ of not only reveals an enhanced neurotransmitter release but also demonstrates increased sensitivity of synaptic exocytosis to extracellular calcium concentration in adult males. Furthermore, the cholinergic synapses in adult males are characterized with weaker synaptic depression but faster vesicle replenishment than that in hermaphrodites. Interestingly, T-type calcium channels/CCA-1 play a male-specific role in acetylcholine release at the NMJs in adult animals. Taken together, our results demonstrate sexually dimorphic differentiation of synaptic mechanisms at the NMJs, and thus provide a new mechanistic insight into how biological sex shapes animal behaviors through sex-shared neurons and circuits.
在动物界中观察到了性别共享行为的两性分化，但潜在的神经生物学机制尚未完全了解。在这里，我们报告了成年动物神经肌肉接头（NMJ）处神经递质释放的两性差异。对蠕虫运动的研究证实了成年动物自发运动中的性别差异，定量荧光分析表明，兴奋性胆碱能突触而非抑制性GABA能突触在雄性和雌雄同体动物的突触小泡中表现出成年特异性差异。对成年动物神经肌肉接头的电生理记录不仅揭示了神经递质释放的增强，还证明了成年雄性突触胞吐作用对细胞外钙浓度的敏感性增加。此外，成年雄性的胆碱能突触的特点是突触抑制较弱，但囊泡补充比雌雄同体动物更快。有趣的是，T型钙通道/CCA-1在成年动物神经肌肉接头处乙酰胆碱释放中发挥雄性特异性作用。综上所述，我们的结果证明了神经肌肉接头处突触机制的两性分化，从而为生物性别如何通过性别共享的神经元和回路塑造动物行为提供了新的机制性见解。
