Strain differences in the development of susceptibility to audiogenic seizures after acoustic priming but not after hearing loss

Abstract

Either exposure to an initial auditory stimulus (IAS) or external ear plugging (EEP) was used to produce susceptibility to audiogenic seizures in C57BL/6Bg and DBA/1Bg mice. After the IAS, increments in seizure susceptibility occurred by 5 h in C57BL/6Bg mice and by 24 h in DBA/1Bg-ras mice, whereas after EEP, increments in seizure susceptibility occurred by 48 h in C57BL/6Bg and by 24 h in DBA/1Bg-ras mice. Because both the IAS and EEP produce hearing loss, the strain differences in the effect of the IAS on the development of susceptibility and the strain similarities in the effect of the EEP on the development of susceptibility support the hypothesis that acoustic priming in the C57BL/6Bg at 19 days of age involves another mechanism in addition to that of hearing loss and disuse supersensitivity. It was suggested elsewhere that the other mechanism is mediated by a post-IAS decrease in the concentration of brain γ-aminobutyric acid and requires brain protein synthesis for a brief period post-IAS.