Department of Psychiatry, Douglas Hospital Research Centre, McGill University, 6875 Boulevard LaSalle, Verdun, QC, H4H 1R3, Canada.
Department of Psychological and Brain Sciences, Rajen Kilachand Center for Integrated Life Sciences and Engineering, Boston University, 610 Commonwealth Avenue, Boston, MA, 02215, USA.
Nat Commun. 2020 Jun 15;11(1):3026. doi: 10.1038/s41467-020-16825-1.
Survival in complex environments necessitates a flexible navigation system that incorporates memory of recent behavior and associations. Yet, how the hippocampal spatial circuit represents latent information independent of sensory inputs and future goals has not been determined. To address this, we image the activity of large ensembles in subregion CA1 via wide-field fluorescent microscopy during a novel behavioral paradigm. Our results demonstrate that latent information is represented through reliable firing rate changes during unconstrained navigation. We then hypothesize that the representation of latent information in CA1 is mediated by pattern separation/completion processes instantiated upstream within the dentate gyrus (DG) and CA3 subregions. Indeed, CA3 ensemble recordings reveal an analogous code for latent information. Moreover, selective chemogenetic inactivation of DG-CA3 circuitry completely and reversibly abolishes the CA1 representation of latent information. These results reveal a causal and specific role of DG-CA3 circuitry in the maintenance of latent information within the hippocampus.
在复杂环境中生存需要一个灵活的导航系统,该系统结合了对最近行为和关联的记忆。然而,海马体空间电路如何在不依赖于感官输入和未来目标的情况下独立表示潜在信息尚未确定。为了解决这个问题,我们在一个新的行为范式中通过宽场荧光显微镜对亚区 CA1 中的大集合体的活动进行成像。我们的结果表明,潜在信息是通过在不受约束的导航过程中可靠的放电率变化来表示的。然后,我们假设 CA1 中潜在信息的表示是由齿状回(DG)和 CA3 亚区上游的模式分离/完成过程介导的。实际上,CA3 集合记录揭示了潜在信息的类似编码。此外,选择性化学遗传失活 DG-CA3 电路完全且可逆地消除了 CA1 中潜在信息的表示。这些结果揭示了 DG-CA3 电路在海马体中维持潜在信息中的因果和特定作用。