Mitochondrial dysfunction and oxidative stress are known to occur following acute seizure activity but their contribution during epileptogenesis is largely unknown. The goal of this study was to determine the extent of mitochondrial oxidative stress, changes to redox status, and
mitochondrial DNA (
mtDNA) damage during epileptogenesis in the
lithium-
pilocarpine model of
temporal lobe epilepsy. Mitochondrial oxidative stress, changes in tissue and mitochondrial redox status, and
mtDNA damage were assessed in the hippocampus and neocortex of Sprague-Dawley rats at time points (24h to 3months) following
lithium-
pilocarpine administration. A time-dependent increase in mitochondrial
hydrogen peroxide (H(2)O(2)) production coincident with increased
mtDNA lesion frequency in the hippocampus was observed during epileptogenesis. Acute increases (24-48h) in H(2)O(2) production and
mtDNA lesion frequency were dependent on the severity of convulsive seizure activity during initial
status epilepticus. Tissue levels of GSH, GSH/
GSSG,
coenzyme A (
CoASH), and
CoASH/
CoASSG were persistently impaired at all measured time points throughout epileptogenesis, that is, acutely (24-48h), during the 'latent period' (48h to 7days), and chronic
epilepsy (21days to 3months). Together with our previous work, these results demonstrate the model independence of mitochondrial oxidative stress,
genomic instability, and persistent impairment of mitochondrial specific redox status during epileptogenesis. Lasting impairment of mitochondrial and tissue redox status during the latent period, in addition to the acute and chronic phases of epileptogenesis, suggests that redox-dependent processes may contribute to the progression of epileptogenesis in experimental
temporal lobe epilepsy.