Epilepsy-Prone .Mice Genetically Determined Sound-Induced Seizures

Many different strains of mice are prone to epilepsy, manifest as either spontaneaus seizures or as seizures occurring in response to specific sensory inputs, such as a loud sound (see Table 1). At least 12 single locus mutations are known that produce neurological syndromes associated with spontaneaus seizures (Noebels, 1979; Seyfried, 1982). The syndromein the mutant mouse tottering (tg/tg) has been proposed as a model of "absence attacks" (Noebels and Sidman, 1979). Distinctive cerebellar abnormalities (loss of granule cells and abnormal synaptic morphology) are found in staggerer mice (Sax et al., 1968). In a mutant (sps recessive) in C57BL/6 Bg mice, spontaneaus seizures, perhaps of limbic origin, are frequently fatal (Maxson et al., 1983). Of the convulsions evoked by sensory Stimulation, the best studied (in terms of genetics, biochemistry, and pharmacology) are audiogenic seizures in DBA/2 mice. Some limited biochemical data are available on the El (epilepsy-like, also called EP) mouse in which postural Stimulation is the sensory trigger (Kurokawa et al., 1966; Suzuki and Nakamoto, 1977). This chapter presents a summary of the information available concerning the abnormality in the DBA/2 mouse and other strains showing sound-induced seizures. The approaches adopted for studying this syndrome could be usefully applied to the other genetic seizure-prone mice strains.