The extracellular matrix regulates cortical layer dynamics and cross-columnar frequency integration in the auditory cortex

Commun Biol. 2021 Mar 10;4(1):322. doi: 10.1038/s42003-021-01837-4.

Abstract

In the adult vertebrate brain, enzymatic removal of the extracellular matrix (ECM) is increasingly recognized to promote learning, memory recall, and restorative plasticity. The impact of the ECM on translaminar dynamics during cortical circuit processing is still not understood. Here, we removed the ECM in the primary auditory cortex (ACx) of adult Mongolian gerbils using local injections of hyaluronidase (HYase). Using laminar current-source density (CSD) analysis, we found layer-specific changes of the spatiotemporal synaptic patterns with increased cross-columnar integration and simultaneous weakening of early local sensory input processing within infragranular layers Vb. These changes had an oscillatory fingerprint within beta-band (25-36 Hz) selectively within infragranular layers Vb. To understand the laminar interaction dynamics after ECM digestion, we used time-domain conditional Granger causality (GC) measures to identify the increased drive of supragranular layers towards deeper infragranular layers. These results showed that ECM degradation altered translaminar cortical network dynamics with a stronger supragranular lead of the columnar response profile.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Auditory Cortex / drug effects
  • Auditory Cortex / metabolism
  • Auditory Cortex / physiology*
  • Auditory Pathways / physiology
  • Auditory Perception* / drug effects
  • Evoked Potentials, Auditory* / drug effects
  • Extracellular Matrix / drug effects
  • Extracellular Matrix / metabolism
  • Extracellular Matrix / physiology*
  • Gerbillinae
  • Hearing
  • Hyaluronoglucosaminidase / administration & dosage
  • Injections
  • Male
  • Time Factors

Substances

  • Hyaluronoglucosaminidase