title: Reduced cortical volume and elevated astrocyte density in rats chronically treated with antipsychotic drugs-linking magnetic resonance imaging findings to cellular pathology.
abstract: BACKGROUND
  Increasing evidence suggests that antipsychotic drugs (APD) might affect brain structure directly, particularly the cerebral cortex. However, the precise anatomical loci of these effects and their underlying cellular basis remain unclear.
  
  
  METHODS
  With ex vivo magnetic resonance imaging in rats treated chronically with APDs, we used automated analysis techniques to map the regions that show maximal impact of chronic (8 weeks) treatment with either haloperidol or olanzapine on the rat cortex. Guided by these imaging findings, we undertook a focused postmortem investigation with stereology.
  
  
  RESULTS
  We identified decreases in the volume and thickness of the anterior cingulate cortex (ACC) after chronic APD treatment, regardless of the APD administered. Postmortem analysis confirmed these volumetric findings and demonstrated that chronic APD treatment had no effect on the total number of neurons or S100β+ astrocytes in the ACC. In contrast, an increase in the density of these cells was observed.
  
  
  CONCLUSIONS
  This study demonstrates region-specific structural effects of chronic APD treatment on the rat cortex, primarily but not exclusively localized to the ACC. At least in the rat, these changes are not due to a loss of either neurons or astrocytes and are likely to reflect a loss of neuropil. Although caution needs to be exerted when extrapolating results from animals to patients, this study highlights the power of this approach to link magnetic resonance imaging findings to their histopathological origins.
authors.affiliation: Department of Psychosis Studies.
authors.forename: Anthony C
authors.initials: AC
authors.lastname: Vernon
authors.affiliation: Department of Neuroimaging, Centre for Neuroimaging Sciences.
authors.forename: William R
authors.initials: WR
authors.lastname: Crum
authors.affiliation: Mouse Imaging Centre, The Hospital for Sick Children and Department of Medical Biophysics, University of Toronto, Toronto, Canada.
authors.forename: Jason P
authors.initials: JP
authors.lastname: Lerch
authors.affiliation: Department of Psychosis Studies.
authors.forename: Winfred
authors.initials: W
authors.lastname: Chege
authors.affiliation: Department of Psychosis Studies.
authors.forename: Sridhar
authors.initials: S
authors.lastname: Natesan
authors.affiliation: Department of Neuroscience, Centre for the Cellular Basis of Behaviour, The James Black Centre, King's College London, Institute of Psychiatry.
authors.forename: Michel
authors.initials: M
authors.lastname: Modo
authors.affiliation: Department of Neuroscience, Centre for the Cellular Basis of Behaviour, The James Black Centre, King's College London, Institute of Psychiatry.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Cooper
authors.affiliation: Department of Neuroimaging, Centre for Neuroimaging Sciences.
authors.forename: Steven C R
authors.initials: SC
authors.lastname: Williams
authors.affiliation: Department of Psychosis Studies. Electronic address: shitij.kapur@kcl.ac.uk.
authors.forename: Shitij
authors.initials: S
authors.lastname: Kapur
mesh_terms: D000818:Animals; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000009:adverse effects*; D001253:Astrocytes / Q000187:drug effects* / Q000473:pathology; D001284:Atrophy / Q000139:chemically induced* / Q000473:pathology; D001569:Benzodiazepines / Q000009:adverse effects; D002452:Cell Count; D002540:Cerebral Cortex / Q000187:drug effects* / Q000473:pathology*; D006220:Haloperidol / Q000009:adverse effects; D008279:Magnetic Resonance Imaging; D008297:Male; D059906:Neuroimaging; D009474:Neurons / Q000187:drug effects; D000077152:Olanzapine; D051381:Rats
chemical_list: D014150:Antipsychotic Agents; D001569:Benzodiazepines; D006220:Haloperidol; D000077152:Olanzapine
keywords: Anterior cingulate; antipsychotic; cortex; haloperidol; magnetic resonance imaging; tensor-based morphometry