Laboratory of Systems Neuroscience, Department of Physiology, University of Bern, Bern, Switzerland.
Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche AG, Basel, Switzerland.
Nat Commun. 2024 Nov 3;15(1):9493. doi: 10.1038/s41467-024-53866-2.
Acquiring and exploiting memories of rewarding experiences is critical for survival. The spatial environment in which a rewarding stimulus is encountered regulates memory retrieval. The ventral hippocampus (vH) has been implicated in contextual memories involving rewarding stimuli such as food, social cues or drugs. Yet, the neuronal representations and circuits underlying contextual memories of socially rewarding stimuli are poorly understood. Here, using in vivo electrophysiological recordings, in vivo one-photon calcium imaging, and optogenetics during a social reward contextual conditioning paradigm in male mice, we show that vH neurons discriminate between contexts with neutral or acquired social reward value. The formation of context-discriminating vH neurons following learning was contingent upon the presence of unconditioned stimuli. Moreover, vH neurons showed distinct contextual representations during the retrieval of social reward compared to fear contextual memories. Finally, optogenetic inhibition of locus coeruleus (LC) projections in the vH selectively disrupted social reward contextual memory by impairing vH contextual representations. Collectively, our findings reveal that the vH integrates contextual and social reward information, with memory encoding of these representations supported by input from the LC.
获取和利用奖励体验的记忆对于生存至关重要。遇到奖励刺激的空间环境调节记忆检索。腹侧海马体 (vH) 与涉及食物、社交线索或药物等奖励刺激的情境记忆有关。然而，社交奖励刺激的情境记忆背后的神经元表示和回路仍知之甚少。在这里，我们使用活体电生理记录、活体单光子钙成像和光遗传学，在雄性小鼠的社交奖励情境条件反射范式中，我们发现 vH 神经元区分具有中性或获得的社交奖励价值的情境。学习后形成的区分情境的 vH 神经元取决于非条件刺激的存在。此外，与恐惧情境记忆相比，vH 神经元在检索社交奖励时表现出不同的情境表示。最后，vH 中蓝斑 (LC) 投射的光遗传学抑制选择性地通过损害 vH 情境表示来破坏社交奖励情境记忆。总的来说，我们的发现表明 vH 整合了情境和社交奖励信息，LC 的输入支持这些表示的记忆编码。
