Vanadium Impairs Neuronal Cytoarchitecture of the Hippocampal Trisyn-aptic Loop in the African Giant Rat (Cricetomys gambianus, Waterhouse)

Environmental pollution with vanadium may pose neurotoxicity threats to known unique neural attributes (cognition and olfaction) of the African giant rat (AGR). This rodent lives within the same ecological zones as the human populace. Thus, experimental investigations on the effect of vanadium on this rodent may mirror latent epidemiological scenarios in the human populace. This work was designed to evaluate the neurotoxic effect of vanadium on the hippocampal neuronal infrastructure and circuitry and provide cellular correlates to its significant pathologies in the AGR. Twelve adult male AGRs were assigned into two groups (n = 6/group; vanadium and control). They were dosed daily with 3 mg/kg body sodium metavanadate and sterile water for 14 days, respectively, and harvested brains were processed for histology. Using Nissl and Golgi staining techniques with stereological analysis, we demonstrated the effect of vanadium on AGR neuronal architecture of the hippocampal trisynaptic loop as a probable cellular mechanism of vanadium-induced memory deficits. Specifically, the most significant pathologies were seen in the dentate gyrus and CA3, with significantly decreased neuronal density disrupted cytoarchitecture and loss of dendritic arborisations and axonal extensions. At the same time, hippocampal subfields CA2 and CA4 showed region-specific resistance to vanadium-induced neurotoxicity. Furthermore, the selective vulnerability to vanadium-induced neurotoxicity is adduced. This work has demonstrated the neurotoxic effect of vanadium on the hippocampal subfields and circuitry in the AGR and highlighted its probable impact on their translational purposes. This rodent may be a suitable model for evaluating memory pathologies in neurotoxicological studies