Epilepsy

Epilepsy is one of the most common disorders of the nervous system, affecting 2.5 million Americans of all ages, races, and ethnic backgrounds. Every year, 181,000 Americans develop epilepsy. Characteristically, epilepsy makes people susceptible to seizures, which, though outwardly varying, are all brought about by brief electrical disturbances in the brain (Epilepsy Foundation, www.epilepsyfoundation.org).

JAX® Mice Models

Four mouse models of absence epilepsy, tottering (B6.D2-Cacna1atg/J, Stock Number 000544), lethargic (B6EiC3Sn a/A-Cacnb4lh/J, Stock Number 000504), ducky (B6;CByJ-Cacna2d2du-3J/J, Stock Number 005050), and stargazer (B6C3Fe a/a- Cacng2stg/J (Stock Number 001756), and two related mutants, waggler (B6.MRL-Cacng2stg-wag/J, Stock Number 001883) and stargazer 3 Jackson (not publicly available), have mutations in voltage-dependent calcium channel (VDCC) subunit genes, indicating these genes have a key role in maintaining normal electrical activity in the brain.

Below, we briefly describe two of these, stargazer and waggler.

B6C3Fe a/a-Cacng2stg/J

Stock Number 001756

Mice homozygous for the spontaneous mutation stargazer (Cacng2stg) are first recognizable 14 days after birth by their smaller body size and slightly ataxic gait. The mutation is named for the abnormal choreiform-like head movements of these mice. Homozygous females are fertile, but most males cannot breed. Symptoms progressively worsen with age, and both males and females live to be a year old or more. Electrocorticographical recordings of stargazer mice reveal frequent, prolonged, generalized spike-wave cortical discharges with behavioral arrest. The abnormal brain wave patterns are similar to those seen in human beings with absence epilepsy.

References

Letts VA, Felix R, Biddlecome GH, Arikkath J, Mahaffey CL, Valenzuela A, Bartlett FS 2nd, Mori Y, Campbell KP, Frankel WN. 1998. The mouse stargazer gene encodes a neuronal Ca2+-channel gamma subunit. Nat Genet 19:340-7.

Letts VA, Mahaffey CL, Beyer B, Frankel WN. 2005. A targeted mutation in Cacng4 exacerbates spike-wave seizures in stargazer (Cacng2) mice. Proc Natl Acad Sci U S A 102:2123-8.

B6.MRL-Cacng2stg-wag/J

Stock Number 001883

Waggler homozygotes manifest a less severe phenotype than stargazer homozygotes, but do display an ataxic gait and occasional seizures. In general, young wagglers are less healthy than are stargazers, but, if they reach weaning age, they usually live for one to two years. Homozygous waggler males and females breed, and they display neither gross neuroanatomical nor histopathologic lesions.

References

Letts VA, Felix R, Biddlecome GH, Arikkath J, Mahaffey CL, Valenzuela A, Bartlett FS 2nd, Mori Y, Campbell KP, Frankel WN. 1998. The mouse stargazer gene encodes a neuronal Ca2+-channel gamma subunit. Nat Genet 19:340-7.

Sweet HO 1993. Waggler and stargazer are allelic. Mouse Genome 91:312-3.

JAX® Mice for Epilepsy Research

See a complete list of JAX® Mice for epilepsy research.