Chronic lead exposure disrupts neurometabolic activity in mouse brain: An ex vivo¹H-[¹³C]-NMR study

Lead poisoning has been identified as a problem in adults as well as in children. Chronic exposure to lead has been implicated in neurological disorders such as amyotrophic lateral sclerosis, Parkinson's disease, and Alzheimer's disease. In the present study, we evaluated the impact of chronic lead exposure on cerebral glutamatergic and GABAergic metabolic activity in mice. C57BL6 mice were provided lead acetate in drinking water for two months. The regional cerebral metabolic activity was measured using ¹H-[¹³C]-NMR spectroscopy in conjunction with infusion of [1,6-¹³C₂]glucose. The blood Pb²⁺ increased significantly in lead acetate treated mice. Concomitantly, there was a significant reduction in the forelimb strength. The level of myo-inositol was elevated in the cerebral cortex of mice chronically exposed to lead. The glutamatergic neurometabolic activity was found to be reduced following chronic lead exposure in the cerebral cortex, hippocampus, and striatum. In contrast, the GABAergic fluxes were impaired in the hippocampus and thalamus only. The metabolic fluxes in the cerebellum were unperturbed to Pb²⁺ toxicity. In conclusion, we report that chronic lead exposure in mice leads to an impairment in forelimb strength, and a perturbation in neurometabolism in brain regions involving cognition and movement.