Muscarinic receptor activation disrupts hippocampal sharp wave-ripples

Brain Res. 2012 Jun 21;1461:1-9. doi: 10.1016/j.brainres.2012.04.037. Epub 2012 Apr 26.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain Waves / drug effects
  • Brain Waves / physiology*
  • CA1 Region, Hippocampal / drug effects
  • CA1 Region, Hippocampal / physiology*
  • Excitatory Postsynaptic Potentials / drug effects
  • Excitatory Postsynaptic Potentials / physiology*
  • Hippocampus / drug effects
  • Hippocampus / physiology
  • Inhibitory Postsynaptic Potentials / drug effects
  • Inhibitory Postsynaptic Potentials / physiology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred ICR
  • Muscarinic Agonists / pharmacology
  • Organ Culture Techniques
  • Receptors, Muscarinic / metabolism*
  • Receptors, Muscarinic / physiology

Substances

  • Muscarinic Agonists
  • Receptors, Muscarinic