Seizure-induced glutamate release in mature and immature animals: an in vivo microdialysis study.

A glutamate biosensor was used to measure extracellular glutamate concentrations in the hippocampus of mature and immature animals. Significant elevations of extracellular glutamate were observed following seizures induced by either kainic acid or pilocarpine. The degree of glutamate increase following seizures was similar in both mature and immature animals. These results suggest that excitotoxicity may play a role in seizure-induced brain damage in the adult brain. In the immature brain, however, no brain damage is seen after seizures, suggesting that glutamate release may not cause as significant excitotoxic damage early in development.