Monaural and binaural audiogenic seizures in mice.

The progression of sound-induced seizures was examined in unilaterally or bilaterally sensitized SJL/J mice tested either monaurally or binaurally. An unexpected right-side advantage for becoming susceptible to audiogenic seizure was observed. In addition, two distinct patterns of seizure progression were noted, a uniphasic sequence in which a single burst of running preceded the convulsion and a biphasic pattern with two such bursts. The biphasic progression is viewed to be the result of unilaterally initiated seizures and characteristically reached only a clonic level of severity. Uniphasic seizures are concluded to be the result of bilaterally initiated seizures and, when they occurred after more than 30 s of auditory stimulation, frequently reached a tonic level of intensity. The present results support the view that audiogenic seizures are characterized by precisely timed, sequential processes dependent upon the specific priming and test procedures employed.