Genetic analysis of serum thyroxine content and audiogenic seizures in recombinant inbred and congenic strains of mice.
We previously proposed that the audiogenic seizure (AGS) susceptibility of 21 +/- 1-day-old DBA/2 (D2) mice may result from an early postnatal elevation in serum thyroxine (T4) concentration. In the present study we used seven C57 X DBA (BXD) recombinant inbred strains and the D2.B6-Iasb congenic strain to study the association between serum T4 content and susceptibility to AGS. The D2.B6-Iasb congenic mice are genetically similar to the D2 mice except for the Iasb gene, which inhibits AGS susceptibility. The total and estimated free serum T4 concentrations in these strains at 14 +/- 1 days of age were compared with the previously determined AGS susceptibilities of these strains at 21 +/- 1 days of age. We found no significant correlations between serum T4 concentration and AGS susceptibility in these strains. It is unlikely, therefore, that inherited differences in neonatal serum T4 content are directly responsible for differences in susceptibility to AGS in 21 +/- 1-day-old mice. The mechanisms by which the experimental manipulation of serum T4 content influences AGS susceptibility are discussed.
D000161:Acoustic Stimulation; D000818:Animals; D005821:Genetic Techniques; D051379:Mice / Q000235:genetics*; D008815:Mice, Inbred Strains; D011995:Recombination, Genetic; D012640:Seizures / Q000097:blood*; D013974:Thyroxine / Q000097:blood*
D013974:Thyroxine