An extensive body of evidence supports the notion that exposure to an enriched/impoverished environment alters brain functions via epigenetic changes. However, how specific modifications of social environment modulate brain functions remains poorly understood. To address this issue, we investigate the molecular and behavioral consequences of briefly manipulating social settings in young and middle-aged wild-type mice. We observe that, modifications of the social context, only affect the performance in socially related tasks. Social enrichment increases sociability whereas isolation leads to the opposite effect. Our work also pointed out specific miRNA signatures associated to each social environment. These miRNA alterations are reversible and found selectively in the medial prefrontal cortex. Finally, we show that miRNA modifications linked to social enrichment or isolation might target rather different intracellular pathways. Together, these observations suggest that the prefrontal cortex may be a key brain area integrating social information via the modification of precise miRNA networks.

大量证据支持这样的观点，即暴露于丰富/贫困的环境会通过表观遗传变化来改变大脑功能。然而，人们对社交环境的特定改变如何调节大脑功能的了解仍然很少。为了解决这个问题，我们研究了在年轻和中年野生型小鼠中短暂操纵社交环境的分子和行为后果。我们观察到，对社会环境的修改只会影响与社会相关的任务的绩效。社会富裕提高了社交能力，而孤立导致相反的效果。我们的工作还指出了与每个社交环境相关的特定miRNA签名。这些miRNA改变是可逆的，并选择性地在内侧前额叶皮层中发现。最后，我们表明，与社会富裕或隔离相关的miRNA修饰可能靶向相当不同的细胞内途径。在一起，这些观察结果表明，前额叶皮层可能是通过修改精确的miRNA网络整合社交信息的关键大脑区域。