PDF(Pubmed)
Abstract：
The dorsal hippocampus (dHPC) is a key brain region for the expression of spatial memories, such as navigating towards a learned reward location. The nucleus accumbens (NAc) is a prominent projection target of dHPC and implicated in value-based action selection. Yet, the contents of the dHPC→NAc information stream and their acute role in behavior remain largely unknown. Here, we found that optogenetic stimulation of the dHPC→NAc pathway while mice navigated towards a learned reward location was both necessary and sufficient for spatial memory-related appetitive behaviors. To understand the task-relevant coding properties of individual NAc-projecting hippocampal neurons (dHPC→NAc), we used in vivo dual-color two-photon imaging. In contrast to other dHPC neurons, the dHPC→NAc subpopulation contained more place cells, with enriched spatial tuning properties. This subpopulation also showed enhanced coding of non-spatial task-relevant behaviors such as deceleration and appetitive licking. A generalized linear model revealed enhanced conjunctive coding in dHPC→NAc neurons which improved the identification of the reward zone. We propose that dHPC routes specific reward-related spatial and behavioral state information to guide NAc action selection.
摘要：
背侧海马(dHPC)是表达空间记忆的关键脑区,例如导航到学习的奖励位置。伏隔核（NAc）是dHPC的突出目标，与基于价值的作用选择有关。然而，dHPC→NAc信息流的内容及其在行为中的急性作用仍在很大程度上未知。这里,我们发现,对于与空间记忆相关的食欲行为,当小鼠导航到学习的奖赏位置时,光遗传学刺激dHPC→NAc途径既是必要的,也是足够的.为了了解单个NAc投射海马神经元（dHPC→NAc）的任务相关编码特性，我们使用了活体双色双光子成像。与其他dHPC神经元相比，dHPC→NAc亚群包含更多的位置细胞，具有丰富的空间调谐特性。该子种群还显示出非空间任务相关行为的增强编码，例如减速和食欲舔。广义线性模型揭示了dHPC→NAc神经元中增强的联合编码，从而改善了奖励区的识别。我们建议dHPC路由特定的奖励相关空间和行为状态信息，以指导NAc行动选择。
