Enhanced intrinsic excitability in basket cells maintains excitatory-inhibitory balance in hippocampal circuits

Neuron. 2013 Feb 20;77(4):712-22. doi: 10.1016/j.neuron.2012.12.020.

Abstract

The dynamics of inhibitory circuits in the cortex is thought to rely mainly on synaptic modifications. We challenge this view by showing that hippocampal parvalbumin-positive basket cells (PV-BCs) of the CA1 region express long-term (>30 min) potentiation of intrinsic neuronal excitability (LTP-IE(PV-BC)) upon brief repetitive stimulation of the Schaffer collaterals. LTP-IE(PV-BC) is induced by synaptic activation of metabotropic glutamate receptor subtype 5 (mGluR5) and mediated by the downregulation of Kv1 channel activity. LTP-IE(PV-BC) promotes spiking activity at the gamma frequency (∼35 Hz) and facilitates recruitment of PV-BCs to balance synaptic and intrinsic excitation in pyramidal neurons. In conclusion, activity-dependent modulation of intrinsic neuronal excitability in PV-BCs maintains excitatory-inhibitory balance and thus plays a major role in the dynamics of hippocampal circuits.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology
  • Animals
  • Animals, Newborn
  • Excitatory Postsynaptic Potentials / physiology*
  • Hippocampus / cytology
  • Hippocampus / physiology*
  • Long-Term Potentiation / physiology*
  • Nerve Net / physiology*
  • Neurons / physiology*
  • Parvalbumins / metabolism
  • Pyramidal Cells / physiology
  • Rats
  • Rats, Wistar
  • Receptor, Metabotropic Glutamate 5
  • Receptors, Metabotropic Glutamate / physiology

Substances

  • Grm5 protein, rat
  • Parvalbumins
  • Receptor, Metabotropic Glutamate 5
  • Receptors, Metabotropic Glutamate