Elevated concentration of glycogen in cobalt induced epileptogenic focus

Changes in the concentration of glycogen in various areas of the brain of epileptic rats were investigated. Epilepsy was induced by implantation of cobalt discs on the right sensory motor cortex and epileptic animals have shown clear tonic-clonic jerks of the contra-lateral fore and hind limbs. It was found that glycogen concentration was increased by 29% in the epileptogenic sensory motor cortex as compared to the same area in the contra-lateral hemisphere. Glycogen concentration in other areas within the same hemisphere remained unaffected. Implantation of nickel or copper on the same sensory motor cortex, which did not cause the typical limb jerks of epilepsy, had no effect on glycogen concentration in the same treated areas. Assay of relevant metabolites in the epileptic cortex showed an increase in the concentration of pyruvate and glucose-6-phosphate, by 218% and 112% respectively. The results suggest that the increased glycogen concentration in epileptogenic focus results from increased uptake of glucose due to neuronal hyperexcitability.