MGlu1α-dependent recruitment of excitatory GABAergic input to neocortical Cajal-Retzius cells

Kathleen E. Cosgrove, Gianmaria MacCaferri*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Scopus citations

Abstract

Cajal-Retzius cells are thought to play an important role for cortical development, and receive primarily spontaneous GABAergic input mediated by GABA A receptors. However, neither the effects of synaptically- released GABA on their excitability nor the cellular source(s) of spontaneous GABAergic currents have been yet determined. By directly recording electrophysiological responses from identified Cajal-Retzius cells of the CXCR4-EGFP mouse, we show that GABAergic input can trigger supra-threshold responses, and that the pharmacological activation of mGlu1α receptors with the group I agonist DHPG powerfully increases the frequency of spontaneous GABAergic currents. These effects appeared mediated by a network mechanism, because responses to DHPG were completely prevented both by surgical disconnection of layer I from lower layers and by exposure of slices to TTX. We propose that the cellular source underlying the observed effect of DHPG are layer I-targeting Martinotti-like interneurons, which we show express functional group I mGluRs and respond to DHPG with supra-threshold depolarization already at early developmental stages. In conclusion, our work suggests that conditions of enhanced glutamate release may be critical at early developmental stages for the recruitment of an mGlu1α-dependent micro-circuit, which then leads to the activation of Cajal-Retzius cells.

Original languageEnglish (US)
Pages (from-to)486-493
Number of pages8
JournalNeuropharmacology
Volume63
Issue number3
DOIs
StatePublished - Sep 2012

Keywords

  • Development
  • Excitability
  • GABA
  • IPSC
  • Interneuron
  • Network

ASJC Scopus subject areas

  • Pharmacology
  • Cellular and Molecular Neuroscience

Fingerprint

Dive into the research topics of 'MGlu1α-dependent recruitment of excitatory GABAergic input to neocortical Cajal-Retzius cells'. Together they form a unique fingerprint.

Cite this