Deletion of Glycogen Synthase Kinase-3β in D2 Receptor-Positive Neurons Ameliorates Cognitive Impairment via NMDA Receptor-Dependent Synaptic Plasticity

Biol Psychiatry. 2020 Apr 15;87(8):745-755. doi: 10.1016/j.biopsych.2019.10.025. Epub 2019 Nov 6.

Abstract

Background: Cortical dopaminergic systems are critically involved in prefrontal cortex (PFC) functions, especially in working memory and neurodevelopmental disorders such as schizophrenia. GSK-3β (glycogen synthase kinase-3β) is highly associated with cAMP (cyclic adenosine monophosphate)-independent dopamine D2 receptor (D2R)-mediated signaling to affect dopamine-dependent behaviors. However, the mechanisms underlying the GSK-3β modulation of cognitive function via D2Rs remains unclear.

Methods: This study explored how conditional cell-type-specific ablation of GSK-3β in D2R+ neurons (D2R-GSK-3β-/-) in the brain affects synaptic function in the medial PFC (mPFC). Both male and female (postnatal days 60-90) mice, including 140 D2R, 24 D1R, and 38 DISC1 mice, were used.

Results: This study found that NMDA receptor (NMDAR) function was significantly increased in layer V pyramidal neurons in mPFC of D2R-GSK-3β-/- mice, along with increased dopamine modulation of NMDAR-mediated current. Consistently, NR2A and NR2B protein levels were elevated in mPFC of D2R-GSK-3β-/- mice. This change was accompanied by a significant increase in enrichment of activator histone mark H3K27ac at the promoters of both Grin2a and Grin2b genes. In addition, altered short- and long-term synaptic plasticity, along with an increased spine density in layer V pyramidal neurons, were detected in D2R-GSK-3β-/- mice. Indeed, D2R-GSK-3β-/- mice also exhibited a resistance of working memory impairment induced by injection of NMDAR antagonist MK-801. Notably, either inhibiting GSK-3β or disrupting the D2R-DISC1 complex was able to reverse the mutant DISC1-induced decrease of NMDAR-mediated currents in the mPFC.

Conclusions: This study demonstrates that GSK-3β modulates cognition via D2R-DISC1 interaction and epigenetic regulation of NMDAR expression and function.

Keywords: Cognition; Dopamine D(2) receptors; Epigenetic; GSK-3β; Histone modification; NMDA receptors; Prefrontal cortex.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cognitive Dysfunction*
  • Epigenesis, Genetic
  • Female
  • Glycogen Synthase Kinase 3 beta / genetics
  • Male
  • Mice
  • Nerve Tissue Proteins
  • Neuronal Plasticity
  • Prefrontal Cortex / metabolism
  • Receptors, Dopamine D2 / genetics
  • Receptors, Dopamine D2 / metabolism
  • Receptors, N-Methyl-D-Aspartate* / genetics
  • Receptors, N-Methyl-D-Aspartate* / metabolism

Substances

  • Disc1 protein, mouse
  • Nerve Tissue Proteins
  • Receptors, Dopamine D2
  • Receptors, N-Methyl-D-Aspartate
  • Glycogen Synthase Kinase 3 beta