Properties of a population of GABAergic cells in murine auditory cortex weakly excited by thalamic stimulation.

  • Verbny Y
  • Erdélyi F
  • Szabó G
 et al. 
  • 35

    Readers

    Mendeley users who have this article in their library.
  • 19

    Citations

    Citations of this article.

Abstract

Feedforward inhibition triggered by thalamocortical (TC) afferents sharpens onset responses and shapes receptive fields of pyramidal cells in auditory cortex (ACx). Previous studies focused only on interneurons located in and around layer IV in primary ACx, target of the dense thalamic projections from ventral medial geniculate. We investigated a population of feedforward interneurons located throughout layers I-V and activated by both afferents from primary and nonprimary thalamus using recordings from auditory TC brain slices obtained from mice expressing green fluorescent protein under control of the glutamic acid decarboxylase (GAD65) promoter in a subpopulation of cortical GABAergic cells. We studied the responses of these interneurons and of pyramidal cells in ACx to thalamic stimulation and to hyper- and depolarizing current pulses. Most interneurons exhibited monosynaptic responses to thalamic stimulation, but this excitation was weak and subthreshold. Interneurons had multipolar dendritic morphology with widespread and dense axonal projections extending several hundred micrometers from the soma. In pyramidal cells from layers II-IV, thalamic excitatory postsynaptic potentials were significantly larger than in interneurons and were superthreshold in 40% of cells, but in these cells, there was no evidence of feedforward inhibition. By contrast, feedforward inhibition was observed in 12 of 18 layer V pyramidal cells. Thus feedforward inhibition in supragranular layers of ACx is weak, and these interneurons require coincident excitation to be activated by thalamic inputs.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

  • Yakov I Verbny

  • Ferenc Erdélyi

  • Gábor Szabó

  • Matthew I Banks

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free