Antipsychotics increase vesicular glutamate transporter 2 (VGLUT2) expression in thalamolimbic pathways

Neuropharmacology. 2008 Mar;54(3):497-508. doi: 10.1016/j.neuropharm.2007.10.022. Epub 2007 Nov 17.

Abstract

Recently the two vesicular-glutamate-transporters VGLUT1 and VGLUT2 have been cloned and characterized. VGLUT1 and VGLUT2 together label all glutamatergic neurons, but because of their distinct expression patterns in the brain they facilitate our ability to define between a VGLUT1-positive cortical and a VGLUT2-positive subcortical glutamatergic systems. We have previously demonstrated an increased cortical VGLUT1 expression as marker of antidepressant activity. Here, we assessed the effects of different psychotropic drugs on brain VGLUT2 mRNA and protein expression. The typical antipsychotic haloperidol, and the atypicals clozapine and risperidone increased VGLUT2 mRNA selectively in the central medial/medial parafascicular, paraventricular and intermediodorsal thalamic nuclei; VGLUT2 protein was accordingly amplified in paraventricular and ventral striatum and in prefrontal cortex. The antidepressants fluoxetine and desipramine and the sedative anxiolytic diazepam had no effect. These results highlight the implication of thalamo-limbic glutamatergic pathways in the action of antipsychotics. Increased VGLUT2 expression in these neurons might constitute a marker for antipsychotic activity and subcortical glutamate neurotransmission might be a possible novel target for future generation antipsychotics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Antipsychotic Agents / pharmacology*
  • Gene Expression Regulation / drug effects*
  • Limbic System / drug effects*
  • Limbic System / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Neural Pathways / drug effects
  • Neural Pathways / metabolism
  • RNA, Messenger / metabolism
  • Thalamus / drug effects*
  • Thalamus / metabolism
  • Vesicular Glutamate Transport Protein 2 / genetics
  • Vesicular Glutamate Transport Protein 2 / metabolism*

Substances

  • Antipsychotic Agents
  • RNA, Messenger
  • Slc17a6 protein, mouse
  • Vesicular Glutamate Transport Protein 2