Roger J. Mullins1, 2, Su Xu1, 3, Jacek A. Mamczarz4, Edna F. R. Pereira4, Edson X. Albuquerque4, Rao P. Gullapalli1
1Core for Translational Research in Imaging, University of Maryland, Baltimore, Baltimore, MD, United States; 2Program in Neuroscience, University of Maryland, Baltimore, Baltimore, MD, United States; 3Department of Diagnostic Radiology & Nuclear Medicine, University of Maryland, Baltimore, Baltimore, MD, United States; 4Division in Translational Toxicology, Department of Epidemiology and Public Health, University of Maryland, Baltimore, Baltimore, MD, United States
Magnetic Resonance Imaging (MRI) and Spectroscopy (MRS) methods were evaluated for their ability to detect CNS changes following acute prepubertal exposure of guinea pigs to chlorpyrifos, an organophosphorus pesticide. Guinea pigs received a subcutaneous injection of either chlorpyrifos or peanut oil . One year later, imaging and spectroscopic changes were correlated with changes in spatial learning behavior in the Morris water maze (MWM). Chlorpyrifos-injected guinea pigs showed significant decreases in performance in the MWM that were associated with a reduction in hippocampal myo-inositol concentration. Results indicate that 1H MR spectroscopy may reveal subtle metabolic changes associated with detrimental organophosphorus exposure.