Peterson Sophie, Chavira Jose, Garcia Arango Jesus Alejandro, Seamans David, Cimino Emma D, Keiflin Ronald
Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA 93106, USA; Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
Curr Biol. 2024 Dec 2;34(23):5532-5545.e3. doi: 10.1016/j.cub.2024.10.049. Epub 2024 Nov 20.
Reward cues are often ambiguous; what is good in one context is not necessarily good in another. To solve this ambiguity, animals form hierarchical associations in which the context gates the retrieval of appropriate cue-evoked memories. These hierarchical associations regulate cue-elicited behavior and influence subsequent learning, promoting the inference of context-dependency. The orbitofrontal cortex (OFC) and dorsal hippocampus (DH) are both proposed to encode a "cognitive map" encompassing hierarchical, context-dependent associations. However, OFC- and DH-specific contributions to the different functional properties of hierarchical associations remain controversial. Using chemogenetic inactivation in rats, we show that the OFC is essential to both properties of hierarchical associations (performance regulation and learning bias). In contrast, DH's role appears limited to the contextual learning bias conferred by hierarchical associations. This work establishes the OFC as a critical orchestrator of hierarchical associations and provides insights into the extended circuits mediating the functional properties of these associations.
奖赏线索往往具有模糊性；在一种情境中有益的事物在另一种情境中未必如此。为了解决这种模糊性，动物会形成层级关联，其中情境控制着对适当线索诱发记忆的提取。这些层级关联调节线索诱发的行为并影响后续学习，促进对情境依赖性的推断。眶额皮质（OFC）和背侧海马体（DH）都被认为编码了一种“认知地图”，其中包含层级的、依赖情境的关联。然而，OFC和DH对层级关联不同功能特性所起的特定作用仍存在争议。通过对大鼠进行化学遗传学失活实验，我们发现OFC对层级关联的两种特性（行为表现调节和学习偏差）都至关重要。相比之下，DH的作用似乎仅限于层级关联赋予的情境学习偏差。这项研究确立了OFC作为层级关联关键协调者的地位，并为介导这些关联功能特性的扩展神经回路提供了见解。
