Increased expression of mitochondrial respiratory enzymes in the brain of epilepsy-prone, naive EL mice.

The present studies demonstrate that expression of both type 5 and type 6 subunits of NADH dehydrogenase and the type 1 subunit of cytochrome oxidase is enhanced significantly in the brains of naive, epilepsy-prone EL mice. In contrast, no apparent change in expression occurred with type 1 and type 2 subunits of NADH dehydrogenase. When expression of type 5 and 6 subunits of NADH dehydrogenase was determined at 24 h after a single series of vestibular stimulation, significant down-regulation was detected. The expression of subunit 2 of NADH dehydrogenase augmented gradually after vestibular stimulation. The increased expression of these mitochondrial respiratory enzymes may reflect enhanced demand for energy due to inherent, spontaneous neuronal hyperactivity in the brains of EL mice.