Longitudinal Differences in Human Hippocampal Connectivity During Episodic Memory Processing

• DOI: 10.1093/texcom/tgaa010
• Publication Date: 2020-04-14T06:36:04Z
• Authors: Kyuwan Choi; Lisa Bagen; Linley Robinson; Gray Umbach; Michael Rugg; Bradley Lega
• Keywords: 03 medical and health sciences; 0302 clinical medicine; Original Article

The question of longitudinal hippocampal functional specialization is critical to human episodic memory because an accurate understanding this phenomenon would impact theories mnemonic function and entail practical consequences for the clinical management patients undergoing temporal lobe surgery. implementation robotically assisted stereo electroencephalography technique seizure mapping has provided our group with opportunity obtain recordings simultaneously from anterior posterior hippocampus, allowing us create unparalleled data set subjects simultaneous along several cortical regions. Using these data, we address key questions governing connectivity in memory. First, ask whether networks during encoding retrieval are significantly different versus hippocampus (PH). We also examine how connections differ across 2-5 Hz 4-9 theta frequency ranges, directly addressing relative contribution each separate bands hippocampal-cortical interactions. While report some overlapping connections, observe evidence distinct related frontal parietal as well hemispheric differences aggregate connectivity. frame findings light proposed AT/PM systems. patterns between networks, find that overall greater PH right hemisphere, further terms place context existing theoretical treatments systems, especially system. During retrieval, significant slow-theta (2-5 Hz) fast-theta (4-9 cortex hippocampus. Finally, test oscillations propagate within using phase slope index estimate direction travel retrieval. uncover posterior-to-anterior direction, while 5-9 anterior-to-posterior. Taken together, describe mnemonically relevant axis will inform interpretation models seek integrate rodent data.