本期封面所示为进行社会性游戏的巢鼠（禾鼠）。人们此前一直不知道社会奖赏编码背后的神经机制，尽管需要增强适应性社会互动来在整个演化过程中始终保持这样的行为。Robert Malenka及同事在本文中报告说，在小鼠伏隔核中，肽激素“后叶催产素”对于向“中等多棘神经元”上的激发性传输的社会性增强和一种形式的突触前长期抑制来说都是所必需的。如果“后叶催产素”受体被特意从来自“背缝神经核”（脑中5-羟色胺的主要来源）的输入中删除的话，这种社会性增强就会被中断；通过阻断伏隔核中的5-羟色胺受体，这种社会性增强也会被中断。“后叶催产素”和5-羟色胺系统之间这种协调的活性，为编码社会性增强提供了一个可能的机制，也为进一步研究社会功能失调的神经机制提供了目标。封面：Jean-Louis Klein & Marie-Luce Hubert。（生物谷 Bioon.com）
生物谷推荐的英文摘要
Nature doi:10.1038/nature12518
Social reward requires coordinated activity of nucleus accumbens oxytocin and serotonin
Gül Dölen, Ayeh Darvishzadeh, Kee Wui Huang & Robert C. Malenka
Social behaviours in species as diverse as honey bees and humans promote group survival but often come at some cost to the individual. Although reinforcement of adaptive social interactions is ostensibly required for the evolutionary persistence of these behaviours, the neural mechanisms by which social reward is encoded by the brain are largely unknown. Here we demonstrate that in mice oxytocin acts as a social reinforcement signal within the nucleus accumbens core, where it elicits a presynaptically expressed long-term depression of excitatory synaptic transmission in medium spiny neurons. Although the nucleus accumbens receives oxytocin-receptor-containing inputs from several brain regions, genetic deletion of these receptors specifically from dorsal raphe nucleus, which provides serotonergic (5-hydroxytryptamine; 5-HT) innervation to the nucleus accumbens, abolishes the reinforcing properties of social interaction. Furthermore, oxytocin-induced synaptic plasticity requires activation of nucleus accumbens 5-HT1B receptors, the blockade of which prevents social reward. These results demonstrate that the rewarding properties of social interaction in mice require the coordinated activity of oxytocin and 5-HT in the nucleus accumbens, a mechanistic insight with implications for understanding the pathogenesis of social dysfunction in neuropsychiatric disorders such as autism.
