Prefrontal–Hippocampal Interaction Supports Episodic-like Memory  

前額葉－海馬體交互作用支持類情節性記憶功能  

Episodic memory refers to the ability to encode and retrieve specific events together with their spatial and temporal context—what happened, where, and when. Whether non-human animals possess this capacity remains debated; however, converging evidence indicates that birds, non-human primates, and rodents express an episodic-like form of memory. In this study, we adapted a rodent episodic-like memory paradigm based on a novelty object preference task to create a structured context in which four objects were associated with distinct spatial and temporal features. Using circuit-level manipulations, we demonstrate that hippocampal CA3 is critical for integrating object, spatial, and temporal information, whereas CA1 is required for accurate behavioral expression of this integrated memory. Furthermore, functional interaction between CA3 and the medial prefrontal cortex is necessary for successful task performance. Together, these findings support the existence of episodic-like memory in rodents and identify a prefrontal–hippocampal circuit mechanism underlying the integration and retrieval of complex experiential information. 

情節性記憶（episodic memory）指的是個體能夠編碼並提取特定事件的能力，包含事件發生的內容（what）、地點（where）與時間（when）。非人類動物是否具備此種認知能力仍具爭議；然而，越來越多的研究顯示，包括鳥類、非人類靈長類與囓齒類動物在內的多種物種，皆表現出情節性記憶的原型形式（prototype）。本研究基於新穎物體偏好（novelty object preference）的囓齒類情節性記憶行為範式，在控制的情境中設置四個物體，並賦予其不同的時序與空間特徵。透過迴路層級的操作，我們發現海馬體 CA3 區對於物體、空間與時間資訊的整合至關重要，而 CA1 區則主要負責此類「類情節記憶」的行為表現。此外，CA3 與內側前額葉皮質之間的功能性互動對於任務表現是必要的。綜合而言，這些結果支持囓齒類動物具備情節性記憶的原型，並揭示前額葉—海馬體神經迴路在複雜經驗資訊整合與提取中的關鍵角色。

References 參考文獻

Chao et al., 2022 Neuroscience & Biobehavioral Reviews.

Chao et al., 2020 Neuroscience & Biobehavioral Reviews.

de Souza Silva et al., 2016 Cerebral Cortex.

Chao et al., 2015 Hippocampus.

Intranasal Dopamine Administration Mediates Brain functions  

鼻腔內多巴胺注射調節腦功能  

Dopamine (DA) is a central neuromodulator that regulates a broad range of brain functions, including cognition, emotion, memory, and motor control. Because DA does not readily cross the blood–brain barrier, intranasal administration has emerged as a noninvasive strategy to deliver DA directly to the central nervous system. Experimental studies demonstrate that intranasal DA increases extracellular DA levels in the striatum and nucleus accumbens and produces beneficial effects across multiple animal models, including aging, Parkinson’s disease, Alzheimer’s disease, schizophrenia, and autism spectrum disorder. Beyond its effects on subcortical dopaminergic targets, intranasal DA also stabilizes the temporal dynamics of glutamatergic neuronal activity in the mouse prefrontal cortex, enhancing the reliability of cortical population signaling. Together, these findings suggest that intranasal DA modulates both dopaminergic and cortical network function, supporting its potential as a translational approach for restoring neuromodulatory balance and cognitive stability in neuropsychiatric and neurodegenerative conditions. 

多巴胺（dopamine）是一種關鍵的神經傳導物質，廣泛調控認知、情緒、記憶與運動等多種腦功能。由於多巴胺本身無法有效通過血腦屏障，鼻內給藥（intranasal administration）因此成為一種可使多巴胺進入中樞神經系統的非侵入性替代策略。研究顯示，鼻內給予多巴胺可提高紋狀體與伏隔核中的細胞外多巴胺濃度，並在多種動物模型，包括老化、帕金森氏症、阿茲海默症、思覺失調症與自閉症譜系障礙中，展現有益效果。此外，鼻內多巴胺亦能調節小鼠前額葉皮質中麩胺酸能神經元活動的時間穩定性，提升皮質神經群體動態的可靠性。綜合而言，這些結果顯示鼻內多巴胺同時影響多巴胺能系統與皮質神經網絡功能，並支持其作為恢復神經傳導物質平衡與認知穩定性的潛在轉譯治療策略，適用於多種神經精神疾患與神經退化性疾病。 

References 參考文獻

Chao et al., 2026 iScience Revision.

Li et al., 2021 Psychopharmacology. 

Chao et al., 2020 Molecular Brain.