title: 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.
authors: Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA.
authors: Dong V
authors: DV
authors: Wang
authors: Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA.
authors: Hau-Jie
authors: HJ
authors: Yau
authors: Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA.
authors: Carl J
authors: CJ
authors: Broker
authors: Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA.
authors: Jen-Hui
authors: JH
authors: Tsou
authors: Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA.
authors: Antonello
authors: A
authors: Bonci
authors: Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA.
authors: Satoshi
authors: S
authors: Ikemoto
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D001683:Biological Clocks; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D056547:CA1 Region, Hippocampal / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology; D005239:Fear; D059330:GABAergic Neurons / Q000502:physiology; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D008568:Memory / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D062308:Optogenetics; D010775:Photic Stimulation; D011897:Random Allocation; D011903:Raphe Nuclei / Q000502:physiology*; D059326:Serotonergic Neurons / Q000502:physiology