Robson Emma, Donahue Margaret M, Mably Alexandra J, Demetrovich Peyton G, Hewitt Lauren T, Colgin Laura Lee
Center for Learning and Memory, The University of Texas at Austin, Austin, TX 78712.
Department of Neuroscience, The University of Texas at Austin, Austin, TX 78712.
bioRxiv. 2024 Sep 19:2024.07.16.603738. doi: 10.1101/2024.07.16.603738.
Hippocampal region CA2 is essential for social memory processing. Interaction with social stimuli induces changes in CA2 place cell firing during active exploration and sharp wave-ripples during rest following a social interaction. However, it is unknown whether these changes in firing patterns are caused by integration of multimodal social stimuli or by a specific sensory modality associated with a social interaction. Rodents rely heavily on chemosensory cues in the form of olfactory signals for social recognition processes. To determine the extent to which social olfactory signals contribute to CA2 place cell responses to social stimuli, we recorded CA2 place cells in rats freely exploring environments containing stimuli that included or lacked olfactory content. We found that CA2 place cell firing patterns significantly changed only when social odors were prominent. Also, place cells that increased their firing in the presence of social odors alone preferentially increased their firing during subsequent sharp wave-ripples. Our results suggest that social olfactory cues are essential for changing CA2 place cell firing patterns during and after social interactions. These results support prior work suggesting CA2 performs social functions and shed light on processes underlying CA2 responses to social stimuli.
海马体CA2区域对于社交记忆处理至关重要。在主动探索过程中,与社交刺激的相互作用会诱发CA2位置细胞放电的变化,而在社交互动后的休息期间,会诱发尖波涟漪的变化。然而,尚不清楚这些放电模式的变化是由多模态社交刺激的整合引起的,还是由与社交互动相关的特定感觉模态引起的。啮齿动物在社交识别过程中严重依赖嗅觉信号形式的化学感觉线索。为了确定社交嗅觉信号在多大程度上促成了CA2位置细胞对社交刺激的反应,我们在自由探索包含有或没有嗅觉内容刺激的环境中的大鼠身上记录了CA2位置细胞。我们发现,只有当社交气味显著时,CA2位置细胞的放电模式才会发生显著变化。此外,仅在社交气味存在时放电增加的位置细胞在随后的尖波涟漪期间优先增加其放电。我们的结果表明,社交嗅觉线索对于在社交互动期间和之后改变CA2位置细胞的放电模式至关重要。这些结果支持了之前表明CA2执行社交功能的工作,并揭示了CA2对社交刺激反应的潜在过程。