title: Parvalbumin-expressing interneurons coordinate hippocampal network dynamics required for memory consolidation.
abstract: Activity in hippocampal area CA1 is essential for consolidating episodic memories, but it is unclear how CA1 activity patterns drive memory formation. We find that in the hours following single-trial contextual fear conditioning (CFC), fast-spiking interneurons (which typically express parvalbumin (PV)) show greater firing coherence with CA1 network oscillations. Post-CFC inhibition of PV+ interneurons blocks fear memory consolidation. This effect is associated with loss of two network changes associated with normal consolidation: (1) augmented sleep-associated delta (0.5-4 Hz), theta (4-12 Hz) and ripple (150-250 Hz) oscillations; and (2) stabilization of CA1 neurons' functional connectivity patterns. Rhythmic activation of PV+ interneurons increases CA1 network coherence and leads to a sustained increase in the strength and stability of functional connections between neurons. Our results suggest that immediately following learning, PV+ interneurons drive CA1 oscillations and reactivation of CA1 ensembles, which directly promotes network plasticity and long-term memory formation.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Nicolette
authors.initials: N
authors.lastname: Ognjanovski
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Samantha
authors.initials: S
authors.lastname: Schaeffer
authors.affiliation: Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Jiaxing
authors.initials: J
authors.lastname: Wu
authors.affiliation: Biophysics Program, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Sima
authors.initials: S
authors.lastname: Mofakham
authors.affiliation: Biophysics Program, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Maruyama
authors.affiliation: Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109, USA.|Biophysics Program, University of Michigan, Ann Arbor, Michigan 48109, USA.|Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Michal
authors.initials: M
authors.lastname: Zochowski
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Sara J
authors.initials: SJ
authors.lastname: Aton
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D056547:CA1 Region, Hippocampal / Q000378:metabolism / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D007395:Interneurons / Q000378:metabolism / Q000502:physiology*; D007858:Learning / Q000502:physiology; D008297:Male; D008568:Memory / Q000502:physiology*; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009415:Nerve Net / Q000378:metabolism / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology; D010320:Parvalbumins / Q000235:genetics / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: D010320:Parvalbumins