title: Muscarinic receptor activation disrupts hippocampal sharp wave-ripples.
abstract: Cholinergic muscarinic innervations to the hippocampus play a role in learning and memory. Here we report that pharmacological activation of muscarinic receptors eliminates sharp wave-ripple events in the mouse hippocampal CA1 region in vivo and in vitro. This effect was associated with a decorrelation of excitatory synaptic inputs and a net increase in inhibitory conductances in pyramidal neurons. Multineuron calcium imaging revealed that muscarinic activation altered the spatiotemporal pattern of network activities. Thus, cholinergic input is likely to contribute to a neuromodulatory switch of hippocampal network states, as proposed in the "two-stage" model of learning processes.
authors.affiliation: Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Norimoto
authors.forename: Mika
authors.initials: M
authors.lastname: Mizunuma
authors.forename: Daisuke
authors.initials: D
authors.lastname: Ishikawa
authors.forename: Norio
authors.initials: N
authors.lastname: Matsuki
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ikegaya
mesh_terms: D000818:Animals; D058256:Brain Waves / Q000187:drug effects / Q000502:physiology*; D056547:CA1 Region, Hippocampal / Q000187:drug effects / Q000502:physiology*; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology; D053444:Inhibitory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D018721:Muscarinic Agonists / Q000494:pharmacology; D009924:Organ Culture Techniques; D011976:Receptors, Muscarinic / Q000378:metabolism* / Q000502:physiology
chemical_list: D018721:Muscarinic Agonists; D011976:Receptors, Muscarinic