Loss of dendritic connectivity in CA1, CA2, and CA3 neurons in hippocampus in rat under aluminum toxicity: antidotal effect of pyridoxine.

Aluminum chloride (AlCl(3); 4 mg/kg) was injected into the cerebrospinal fluid of adult rats as a one time dose. Rapid Golgi stained sections of hippocampus were examined for detailed histology of neurons in CA1, CA2, and CA3 areas. The axonal length and number of dendritic branches were seen reduced 30 days later in aluminum (Al)-injected group when compared to vehicle-injected controls. Of these perturbations, dendritic branches were seen reduced significantly. Al toxicity apparently affects neuronal connectivity in hippocampus. These perturbations are reversed by supplementing the feed with pyridoxine (8 mg/kg) for 30 days. As the loss of synaptic connectivity is a predominant feature of neurodegenerative disorders such as Alzheimer disease, this study may have implications in such disorders. Pyridoxine may be considered as a potent antidote to Al toxicity and neurodegenerative disorders such as Alzheimer disease.