Interruption of rat absence seizures by auditory stimulation.

Absence seizures are episodes of impaired consciousness and responsiveness that impact an individual's ability to interact with the world around them. Childhood absence epilepsy, a condition defined by these seizures, can have profound effects on children's social, educational, and psychological development. Absence seizures are accompanied by a distinctive electrographic signature called a spike-wave discharge. The impairment of consciousness associated with a spike-wave discharge can be variable: some people maintain responsiveness during some absence seizures, and some rodent oscillations resembling spike-wave discharges may not have any behavioral impact. We previously observed that spike-wave discharges in the Genetic Absence Epilepsy Rat from Strasbourg model sometimes terminated shortly after presentation of a conditioned auditory stimulus. In this study we found that these terminations were caused by the stimuli and that they occurred after approximately 50% of stimuli. We also found that the probability of a spike-wave discharge being interrupted depended on stimulus timing, degree of conditioning, and electrographic signal power. These data provide insight into the factors that determine the mechanisms of absence seizure termination, with possible implications for therapy.