Disruptions in social behaviour are prevalent in many neuropsychiatric disorders such as schizophrenia, bipolar disorder and autism spectrum disorders. However, the underlying neurochemical regulation of social behaviour is still not well understood. The central cholinergic system has been proposed to contribute to the regulation of social behaviour. For instance, decreased global levels of acetylcholine release in the brain leads to decreased social interaction and an impairment of social memory in mice. Nonetheless, it has been difficult to ascertain the specific brain areas where cholinergic signalling influences social preference and social memory. In this study, we investigated the impact of different forebrain cholinergic regions on social behaviour by examining mouse lines that differ in their regional expression level of the vesicular acetylcholine transporter—the protein that regulates acetylcholine secretion. We found that when cholinergic signalling is highly disrupted in the striatum, hippocampus, cortex and amygdala mice have intact social preference but are impaired in social memory, as they cannot remember a familiar conspecific nor recognize a novel one. A similar pattern emerges when acetylcholine release is disrupted mainly in the striatum, cortex, and amygdala; however, the ability to recognize novel conspecifics is retained. In contrast, cholinergic signalling of the striatum and amygdala does not appear to significantly contribute to the modulation of social memory and social preference. Furthermore, we demonstrated that increasing global cholinergic tone does not increase social behaviours. Together, these data suggest that cholinergic transmission from the hippocampus and cortex are important for regulating social memory.

中文翻译：

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来自基底前脑的胆碱能传递调节雄性小鼠的社会记忆

社会行为紊乱在许多神经精神疾病中很普遍，例如精神分裂症、双相情感障碍和自闭症谱系障碍。然而，社会行为的潜在神经化学调节仍不清楚。已提出中枢胆碱能系统有助于调节社会行为。例如，大脑中乙酰胆碱释放的整体水平降低导致小鼠社交互动减少和社交记忆受损。尽管如此，很难确定胆碱能信号影响社会偏好和社会记忆的特定大脑区域。在这项研究中，我们通过检查在囊泡乙酰胆碱转运蛋白（调节乙酰胆碱分泌的蛋白质）的区域表达水平上不同的小鼠品系，研究了不同前脑胆碱能区域对社会行为的影响。我们发现，当纹状体中的胆碱能信号受到严重干扰时，海马、皮层和杏仁核小鼠具有完整的社会偏好，但社会记忆受损，因为它们无法记住熟悉的同种动物，也无法识别新的动物。当乙酰胆碱的释放主要在纹状体、皮质和杏仁核中受到干扰时，就会出现类似的模式；然而，识别新同种的能力被保留。相比之下，纹状体和杏仁核的胆碱能信号似乎对社会记忆和社会偏好的调节没有显着贡献。此外，我们证明了增加全球胆碱能基调不会增加社交行为。总之，这些数据表明来自海马体和皮层的胆碱能传递对于调节社会记忆很重要。