Environmental Enrichment and Social Isolation Mediate Neuroplasticity of Medium Spiny Neurons through the GSK3 Pathway

Cell Rep. 2018 Apr 10;23(2):555-567. doi: 10.1016/j.celrep.2018.03.062.

Abstract

Resilience and vulnerability to neuropsychiatric disorders are linked to molecular changes underlying excitability that are still poorly understood. Here, we identify glycogen-synthase kinase 3β (GSK3β) and voltage-gated Na+ channel Nav1.6 as regulators of neuroplasticity induced by environmentally enriched (EC) or isolated (IC) conditions-models for resilience and vulnerability. Transcriptomic studies in the nucleus accumbens from EC and IC rats predicted low levels of GSK3β and SCN8A mRNA as a protective phenotype associated with reduced excitability in medium spiny neurons (MSNs). In vivo genetic manipulations demonstrate that GSK3β and Nav1.6 are molecular determinants of MSN excitability and that silencing of GSK3β prevents maladaptive plasticity of IC MSNs. In vitro studies reveal direct interaction of GSK3β with Nav1.6 and phosphorylation at Nav1.6T1936 by GSK3β. A GSK3β-Nav1.6T1936 competing peptide reduces MSNs excitability in IC, but not EC rats. These results identify GSK3β regulation of Nav1.6 as a biosignature of MSNs maladaptive plasticity.

Keywords: GSK3β; Nav1.6; enriched environment; isolated condition; medium spiny neurons; neuronal firing; persistent sodium current; plasticity; reward pathway.

MeSH terms

  • Animals
  • Evoked Potentials
  • Glycogen Synthase Kinase 3 beta / antagonists & inhibitors
  • Glycogen Synthase Kinase 3 beta / genetics
  • Glycogen Synthase Kinase 3 beta / metabolism*
  • HEK293 Cells
  • Humans
  • Male
  • NAV1.6 Voltage-Gated Sodium Channel / chemistry
  • NAV1.6 Voltage-Gated Sodium Channel / genetics
  • NAV1.6 Voltage-Gated Sodium Channel / metabolism
  • Neuronal Plasticity / physiology*
  • Neurons / metabolism*
  • Patch-Clamp Techniques
  • Phosphopeptides / analysis
  • Physical Conditioning, Animal*
  • Protein Binding
  • RNA Interference
  • RNA, Small Interfering / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Social Isolation*
  • Transcriptome

Substances

  • NAV1.6 Voltage-Gated Sodium Channel
  • Phosphopeptides
  • RNA, Small Interfering
  • Glycogen Synthase Kinase 3 beta