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Mesopontine median raphe regulates hippocampal ripple oscillation and memory consolidation.

ABSTRACT: Sharp wave-associated field oscillations (?200 Hz) of the hippocampus, referred to as ripples, are believed to be important for consolidation of explicit memory. Little is known about how ripples are regulated by other brain regions. We found that the median raphe region (MnR) is important for regulating hippocampal ripple activity and memory consolidation. We performed in vivo simultaneous recording in the MnR and hippocampus of mice and found that, when a group of MnR neurons was active, ripples were absent. Consistently, optogenetic stimulation of MnR neurons suppressed ripple activity and inhibition of these neurons increased ripple activity. Notably, using a fear conditioning procedure, we found that photostimulation of MnR neurons interfered with memory consolidation. Our results demonstrate a critical role of the MnR in regulating ripples and memory consolidation.

SUBMITTER: Wang DV

PROVIDER: S-EPMC4414896 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature

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Mesopontine median raphe regulates hippocampal ripple oscillation and memory consolidation.

Wang Dong V DV Yau Hau-Jie HJ Broker Carl J CJ Tsou Jen-Hui JH Bonci Antonello A Ikemoto Satoshi S

Nature neuroscience 20150413 5

Sharp wave-associated field oscillations (∼200 Hz) of the hippocampus, referred to as ripples, are believed to be important for consolidation of explicit memory. Little is known about how ripples are regulated by other brain regions. We found that the median raphe region (MnR) is important for regulating hippocampal ripple activity and memory consolidation. We performed in vivo simultaneous recording in the MnR and hippocampus of mice and found that, when a group of MnR neurons was active, rippl ...[more]

PMID: 25867120

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