Identified sources and targets of slow inhibition in the neocortex

Science. 2003 Mar 21;299(5614):1902-5. doi: 10.1126/science.1082053.

Abstract

There are two types of inhibitory postsynaptic potentials in the cerebral cortex. Fast inhibition is mediated by ionotropic gamma-aminobutyric acid type A (GABA(A)) receptors, and slow inhibition is due to metabotropic GABA(B) receptors. Several neuron classes elicit inhibitory postsynaptic potentials through GABA(A) receptors, but possible distinct sources of slow inhibition remain unknown. We identified a class of GABAergic interneurons, the neurogliaform cells, that, in contrast to other GABA-releasing cells, elicited combined GABA(A) and GABA(B) receptor-mediated responses with single action potentials and that predominantly targeted the dendritic spines of pyramidal neurons. Slow inhibition evoked by a distinct interneuron in spatially restricted postsynaptic compartments could locally and selectively modulate cortical excitability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials
  • Animals
  • Bicuculline / pharmacology
  • Dendrites / physiology
  • Evoked Potentials
  • GABA Antagonists / pharmacology
  • GABA-A Receptor Antagonists
  • GABA-B Receptor Antagonists
  • Interneurons / physiology*
  • Interneurons / ultrastructure
  • Neocortex / cytology
  • Neocortex / physiology*
  • Neural Inhibition*
  • Organophosphorus Compounds / pharmacology
  • Patch-Clamp Techniques
  • Pyramidal Cells / physiology*
  • Pyridazines / pharmacology
  • Rats
  • Rats, Wistar
  • Receptors, GABA-A / physiology
  • Receptors, GABA-B / physiology
  • Somatosensory Cortex / cytology
  • Somatosensory Cortex / physiology*
  • Synapses / physiology
  • Synapses / ultrastructure
  • Synaptic Transmission*

Substances

  • GABA Antagonists
  • GABA-A Receptor Antagonists
  • GABA-B Receptor Antagonists
  • Organophosphorus Compounds
  • Pyridazines
  • Receptors, GABA-A
  • Receptors, GABA-B
  • CGP 35348
  • gabazine
  • Bicuculline