Brain-Specific SNAP-25 Deletion Leads to Elevated Extracellular Glutamate Level and Schizophrenia-Like Behavior in Mice

Neural Plast. 2017:2017:4526417. doi: 10.1155/2017/4526417. Epub 2017 Nov 28.

Abstract

Several studies have associated reduced expression of synaptosomal-associated protein of 25 kDa (SNAP-25) with schizophrenia, yet little is known about its role in the illness. In this paper, a forebrain glutamatergic neuron-specific SNAP-25 knockout mouse model was constructed and studied to explore the possible pathogenetic role of SNAP-25 in schizophrenia. We showed that SNAP-25 conditional knockout (cKO) mice exhibited typical schizophrenia-like phenotype. A significantly elevated extracellular glutamate level was detected in the cerebral cortex of the mouse model. Compared with Ctrls, SNAP-25 was dramatically reduced by about 60% both in cytoplasm and in membrane fractions of cerebral cortex of cKOs, while the other two core members of SNARE complex: Syntaxin-1 (increased ~80%) and Vamp2 (increased ~96%) were significantly increased in cell membrane part. Riluzole, a glutamate release inhibitor, significantly attenuated the locomotor hyperactivity deficits in cKO mice. Our findings provide in vivo functional evidence showing a critical role of SNAP-25 dysfunction on synaptic transmission, which contributes to the developmental of schizophrenia. It is suggested that a SNAP-25 cKO mouse, a valuable model for schizophrenia, could address questions regarding presynaptic alterations that contribute to the etiopathophysiology of SZ and help to consummate the pre- and postsynaptic glutamatergic pathogenesis of the illness.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal / physiology*
  • Cerebral Cortex / metabolism*
  • Glutamic Acid / metabolism*
  • Mice
  • Mice, Knockout
  • Neurons / metabolism
  • Schizophrenia / genetics
  • Schizophrenia / metabolism*
  • Synaptic Transmission / physiology
  • Synaptosomal-Associated Protein 25 / genetics
  • Synaptosomal-Associated Protein 25 / metabolism*
  • Syntaxin 1 / genetics
  • Syntaxin 1 / metabolism
  • Vesicle-Associated Membrane Protein 2 / genetics
  • Vesicle-Associated Membrane Protein 2 / metabolism

Substances

  • Snap25 protein, mouse
  • Synaptosomal-Associated Protein 25
  • Syntaxin 1
  • Vesicle-Associated Membrane Protein 2
  • vesicle-associated membrane protein 2, mouse
  • Glutamic Acid