Apoptotic mechanisms and the synaptic pathology of schizophrenia

Schizophr Res. 2006 Jan 1;81(1):47-63. doi: 10.1016/j.schres.2005.08.014. Epub 2005 Oct 14.

Abstract

The cortical neuropathology of schizophrenia includes neuronal atrophy, decreased neuropil, and alterations in neuronal density. Taken together with evidence of decreased synaptic markers and dendritic spines, the data suggest that synaptic circuitry is altered. Recent neuroimaging studies also indicate that a progressive loss of cortical gray matter occurs early in the course of schizophrenia. Although the mechanisms underlying these deficits are largely unknown, recent postmortem data implicate a role for altered neuronal apoptosis. Apoptosis, a form of programmed cell death, is regulated by a complex cascade of pro- and anti-apoptotic proteins. Apoptotic activation can lead to rapid neuronal death. However, emerging data also indicate that sub-lethal apoptotic activity can lead to a limited form of apoptosis in terminal neurites and individual synapses to cause synaptic elimination without cell death. For example, in Alzheimer's disease, a localized apoptotic mechanism is thought to contribute to early neurite and synapse loss leading to the initial cognitive decline. Recent studies indicate that apoptotic regulatory proteins and DNA fragmentation patterns are altered in several cortical regions in schizophrenia. This paper will review converging lines of data that implicate synaptic deficits in the pathophysiology of schizophrenia and propose an underlying role for apoptotic dysregulation.

Publication types

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

MeSH terms

  • Apoptosis / physiology
  • Atrophy / pathology
  • Caspases / genetics
  • Cell Count
  • DNA Fragmentation
  • Genes, bcl-2 / genetics
  • Humans
  • Neuroglia / pathology
  • Neurons / pathology
  • Schizophrenia / genetics
  • Schizophrenia / pathology*
  • Schizophrenia / physiopathology*
  • Synapses / pathology*

Substances

  • Caspases