An increase in dendritic plateau potentials is associated with experience-dependent cortical map reorganization

Proc Natl Acad Sci U S A. 2021 Mar 2;118(9):e2024920118. doi: 10.1073/pnas.2024920118.

Abstract

The organization of sensory maps in the cerebral cortex depends on experience, which drives homeostatic and long-term synaptic plasticity of cortico-cortical circuits. In the mouse primary somatosensory cortex (S1) afferents from the higher-order, posterior medial thalamic nucleus (POm) gate synaptic plasticity in layer (L) 2/3 pyramidal neurons via disinhibition and the production of dendritic plateau potentials. Here we address whether these thalamocortically mediated responses play a role in whisker map plasticity in S1. We find that trimming all but two whiskers causes a partial fusion of the representations of the two spared whiskers, concomitantly with an increase in the occurrence of POm-driven N-methyl-D-aspartate receptor-dependent plateau potentials. Blocking the plateau potentials restores the archetypical organization of the sensory map. Our results reveal a mechanism for experience-dependent cortical map plasticity in which higher-order thalamocortically mediated plateau potentials facilitate the fusion of normally segregated cortical representations.

Keywords: barrel cortex; dendritic signaling; posterior medial complex of the thalamus; somatosensory; synaptic plasticity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology*
  • Animals
  • Brain Mapping / methods
  • Dizocilpine Maleate / pharmacology
  • Evoked Potentials, Somatosensory / drug effects
  • Evoked Potentials, Somatosensory / physiology*
  • Excitatory Amino Acid Antagonists / pharmacology
  • GABA Antagonists / pharmacology
  • Gene Expression
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Nerve Net / anatomy & histology
  • Nerve Net / physiology*
  • Neuronal Plasticity / drug effects
  • Optical Imaging
  • Patch-Clamp Techniques
  • Picrotoxin / pharmacology
  • Pyramidal Cells / cytology
  • Pyramidal Cells / drug effects
  • Pyramidal Cells / metabolism
  • Receptors, GABA-A / genetics
  • Receptors, GABA-A / metabolism
  • Receptors, N-Methyl-D-Aspartate / antagonists & inhibitors
  • Receptors, N-Methyl-D-Aspartate / genetics
  • Receptors, N-Methyl-D-Aspartate / metabolism
  • Somatosensory Cortex / anatomy & histology
  • Somatosensory Cortex / physiology*
  • Thalamus / anatomy & histology
  • Thalamus / physiology*
  • Vibrissae / injuries
  • Vibrissae / physiology*

Substances

  • Excitatory Amino Acid Antagonists
  • GABA Antagonists
  • Receptors, GABA-A
  • Receptors, N-Methyl-D-Aspartate
  • Picrotoxin
  • Dizocilpine Maleate