title: Diffusion tensor imaging of cocaine-treated rodents.
abstract: Studies in cocaine-dependent human subjects have shown differences in white matter on diffusion tensor imaging (DTI) compared with non-drug-using controls. It is not known whether the differences in fractional anisotropy (FA) seen on DTI in white matter regions of cocaine-dependent humans result from a pre-existing predilection for drug use or purely from cocaine abuse. To study the effect of cocaine on brain white matter, DTI was performed on 24 rats after continuous infusion of cocaine or saline for 4 weeks, followed by brain histology. Voxel-based morphometry analysis showed an 18% FA decrease in the splenium of the corpus callosum (CC) in cocaine-treated animals relative to saline controls. On histology, significant increase in neurofilament expression (125%) and decrease in myelin basic protein (40%) were observed in the same region in cocaine-treated animals. This study supports the hypothesis that chronic cocaine use alters white matter integrity in human CC. Unlike humans, where the FA in the genu differed between cocaine users and non-users, the splenium was affected in rats. These differences between rodent and human findings could be due to several factors that include differences in the brain structure and function between species and/or the dose, timing, and duration of cocaine administration.
authors.affiliation: Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, Houston, TX 77030, USA. ponnada.a.narayana@uth.tmc.edu
authors.forename: Ponnada A
authors.initials: PA
authors.lastname: Narayana
authors.forename: Pallavi
authors.initials: P
authors.lastname: Ahobila-Vajjula
authors.forename: Jaivijay
authors.initials: J
authors.lastname: Ramu
authors.forename: Juan
authors.initials: J
authors.lastname: Herrera
authors.forename: Joel L
authors.initials: JL
authors.lastname: Steinberg
authors.forename: F Gerard
authors.initials: FG
authors.lastname: Moeller
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000473:pathology; D003042:Cocaine / Q000493:pharmacokinetics; D019970:Cocaine-Related Disorders / Q000097:blood / Q000473:pathology*; D003337:Corpus Callosum / Q000187:drug effects / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D004292:Dominance, Cerebral / Q000502:physiology; D007091:Image Processing, Computer-Assisted; D015918:Infusion Pumps, Implantable; D008297:Male; D008856:Microscopy, Fluorescence; D004676:Myelin Basic Protein / Q000032:analysis; D009413:Nerve Fibers, Myelinated / Q000187:drug effects / Q000473:pathology; D016900:Neurofilament Proteins / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004676:Myelin Basic Protein; D016900:Neurofilament Proteins; D003042:Cocaine