Resilience and vulnerability to neuropsychiatric disorders are linked to molecular changes underlying excitability that are still poorly understood. Here, we identify glycogen-synthase kinase 3b (GSK3b) 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 GSK3b and SCN8A mRNA as a protective phenotype associated with reduced excitability in medium spiny neurons (MSNs). In vivo genetic manipulations demonstrate that GSK3b and Nav1.6 are molecular determinants of MSN excitability and that silencing of GSK3b prevents maladaptive plasticity of IC MSNs. In vitro studies reveal direct interaction of GSK3b with Nav1.6 and phosphorylation at Nav1.6T1936 by GSK3b. A GSK3b-Nav1.6T1936 competing peptide reduces MSNs excitability in IC, but not EC rats. These results identify GSK3b regulation of Nav1.6 as a biosignature ofMSNs maladaptive plasticity.
- SCN8A mRNA
- neuropsychiatric disorders