Nonconvulsive electrocorticographic paroxysms (absence epilepsy) in rat strains.

Rat strains were screened for evidence of unresponsive periods associated with high-voltage spike and wave paroxysms on electroencephalography--a rodent model of human absence epilepsy. Five commonly used strains were newly noted to express the spike and wave phenomenon. Only an inbred Sprague Dawley rat strain did not exhibit such episodes. The existence of the phenomenon in many and unrelated inbred rat strains suggests that both genetic and environmental factors are causal.