Functional dissociation of hippocampal subregions corresponding to memory types and stages

Journal of Physiological Anthropology

Chaejoon Cheong¹  Ji-Woo Seok² 

[1] Center for Research Equipment, Korea Basic Science Institute, 162 Yeongudanji-ro, Ochang, 28119, Cheongju, Chungbook, Republic of Korea;Department of Psychiatry, University of Nebraska Medical Center, Omaha, NE, USA;Department of Rehabilitation Counseling Psychology, Seoul Hanyoung University, Seoul, Republic of Korea;

关键词: Hippocampus;    Ultra-high field fMRI;    CA 1–3;    Subiculum;    Implicit memory;    Explicit memory;    Encoding;    Retrieval;   

DOI  :  10.1186/s40101-020-00225-x

来源: Springer

【 摘 要 】

BackgroundThe hippocampus reportedly plays a crucial role in memory. However, examining individual human hippocampal-subfield function remains challenging because of their small sizes and convoluted structures. Here, we identified hippocampal subregions involved in memory types (implicit and explicit memory) and stages (encoding and retrieval).MethodsWe modified the serial reaction time task to examine four memory types, i.e. implicit encoding, explicit encoding, implicit retrieval, and explicit retrieval. During this task, 7-T functional magnetic resonance imaging was used to compare brain activity evoked by these memory types.ResultsWe found hippocampal activation according to all memory types and stages and identified that the hippocampus subserves both implicit and explicit memory processing. Moreover, we confirmed that cornu ammonis (CA) regions 1–3 were implicated in both memory encoding and retrieval, whereas the subiculum was implicated only in memory retrieval. We also found that CA 1–3 was activated more for explicit than implicit memory.ConclusionsThese results elucidate human hippocampal-subfield functioning underlying memory and may support future investigations into hippocampal-subfield functioning in health and neurodegenerative disease.

【 授权许可】

CC BY