SOUND-INDUCED SEIZURES IN RABBITS

Abstract

Seventy-three rabbits, 37 to 129 days old, in two sublines of a race of white spotted rabbits which produced some “Vienna White-like” offspring and in which spontaneous epileptic-like seizures had been observed, were exposed to relatively intense auditory stimulation under controlled conditions. Eighteen or 24.7 percent of the group suffered seizures, the seizures being comparable to spontaneous seizures observed by Nachtsheim in the rabbit and to audiogenic seizures in the mouse as described by Vicari. In the group tested the factors of age, sex and subline were not found to have any significant influence on the frequency of occurrence of seizures. Analysis of the pattern of the seizure in the two sublines led to the tentative conclusion that susceptible subjects of the AcEp subline have a lower threshold of reactivity to sound and are more variable than susceptible subjects of the Ac subline with respect to durations of stages of the seizure and of the complete seizure. Further observations indicate that a single test is inadequate for detecting all susceptible animals. Although numbers are small, with possibly one exception, the observations seem to support Nachtsheim's interpretation of inheritance by means of single gene substitution, seizure susceptibility being recessive. The possibility that there may be distinct racial differences determined as in mice by other modifying factors, genetic or environmental, is being investigated further.