Neural and behavioural state switching during hippocampal dentate spikes

• 成果类型: Article
• 署名作者: Farrell, Jordan S.; Hwaun, Ernie; Dudok, Barna; Soltesz, Ivan
• 署名单位: Stanford University; Harvard University; Harvard University Medical Affiliates; Boston Children's Hospital; Harvard University; Harvard Medical School; Baylor College of Medicine
• 刊物名称: Nature
• ISSN/ISSBN: 0028-3956
• DOI: 10.1038/s41586-024-07192-8
• 发表日期: 2024-04-18
• 页码: 590-+
• 关键词: place-cell sequences; sharp-wave-ripple; FRAMEWORK; replay; eeg

摘要

Distinct brain and behavioural states are associated with organized neural population dynamics that are thought to serve specific cognitive functions(1, 2-3). Memory replay events, for example, occur during synchronous population events called sharp-wave ripples in the hippocampus while mice are in an 'offline' behavioural state, enabling cognitive mechanisms such as memory consolidation and planning(4, 5, 6, 7, 8, 9, 10-11). But how does the brain re-engage with the external world during this behavioural state and permit access to current sensory information or promote new memory formation? Here we found that the hippocampal dentate spike, an understudied population event that frequently occurs between sharp-wave ripples(12), may underlie such a mechanism. We show that dentate spikes are associated with distinctly elevated brain-wide firing rates, primarily observed in higher order networks, and couple to brief periods of arousal. Hippocampal place coding during dentate spikes aligns to the mouse's current spatial location, unlike the memory replay accompanying sharp-wave ripples. Furthermore, inhibiting neural activity during dentate spikes disrupts associative memory formation. Thus, dentate spikes represent a distinct brain state and support memory during non-locomotor behaviour, extending the repertoire of cognitive processes beyond the classical offline functions.