Audiogenic seizure susceptibility in WSP and WSR mice

Mice selectively bred for susceptibility (WSP, withdrawal seizure prone) and resistance (WSR, withdrawal seizure resistant) to ethanol (EtOH) withdrawal seizures were tested for susceptibility to audiogenic seizures (AGS). The seizure response of mice was studied at four ages: 17, 22, 28, and 71-78 days. WSR mice exhibited no response at any age, whereas WSP mice were sensitive on days 17, 22, and 28. The maximum number of WSP mice responding to audiogenic stimulation was observed on day 22. However, the frequency and severity of responses by WSP mice was less than that of DBA/2J mice tested under identical conditions (60 vs. 100% showing at least some response). Overall, these data suggest that susceptibility to AGS and handling-induced convulsions (HIC) during EtOH withdrawal may share some common genetic determinants and presumably some common neurochemical systems. Various treatments have been shown to enhance HIC more in WSP as compared with WSR mice. Acoustic stimulation did not induce AGS in adult mice, but the treatment significantly enhanced HIC in WSP but not WSR mice. These data strongly imply that some common neurochemical pathway may regulate susceptibility to HIC elicited by diverse treatments.