Effects of neonatal thyroxine, genotype, and noise on the ear and audiogenic seizures.
Seyfried, Glasser, and Yu recently reported that the DBA/2J mouse genotype, which is innately susceptible to audiogenic seizures, has high neonatal levels of thyroxine (T4) and that neonatal injections of T4 induce susceptibility in the C57BL/6J mouse. In the C57BL/6J mouse, neonatal T4 injections produced a temporary peripheral auditory dysfunction which appeared to be conductive in nature. A cochlear dysfunction was also seen in the DBA/2J mouse and in the acoustically primed C57BL/6J mouse. Since a peripheral auditory threshold elevation in these latter groups of mice appears to be causally related to their susceptibility to audiogenic seizures, it is likely that at least a portion of the susceptibility that Seyfried et al. reported was due to the effects of T4 on the ear.
D000161:Acoustic Stimulation; D000818:Animals; D000831:Animals, Newborn; D001307:Auditory Perception / Q000187:drug effects*; D005838:Genotype; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009622:Noise; D012640:Seizures / Q000139:chemically induced*; D013974:Thyroxine / Q000494:pharmacology*
D013974:Thyroxine