Phenotypes Associated with This Genotype

Genotype
MGI:2655695

• Allelic Composition: Kcna1^tm1Jmay/Kcna1⁺
• Genetic Background: B6.129S4-Kcna1^tm1Jmay

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

behavior/neurological

behavior/neurological phenotype ( J:82778 )

N • heterozygotes display no obvious attacks of ataxia induced by handling

N • under control conditions, heterozygotes display no significant deficits in motor coordination in the accelerating rotarod task over ten successive trials

N • heterozygous rotarod performance is unaffected by saline injection, exercise alone, or injection with the beta-adrenergic agonist isoproterenol (ISO) in the absence of exercise

N • under control conditions, heterozygotes and wild-type mice exhibit the same number of hindfoot missteps while walking across the balance beam

abnormal motor coordination/balance ( J:82778 )

• injection of ISO (10 mg/kg) followed by a 20 min period of exercise on the treadmill significantly reduces the latency of heterozygotes to fall from the accelerating rotarod by ~15 sec, whereas wild-type mice remain unaffected

• a higher dose of ISO (20 mg/kg) followed exercise reduces the latency of heterozygotes to fall to a similar degree, whereas wild-type mice are only moderately affected

• injection of ISO (10 mg/kg) followed by exercise significantly increases the number of hindfoot missteps on the balance beam in heterozygotes, but has little effect on wild-type littermates

• injection of acetazolamide (AZT), a carbonic anhydrase inhibitor, at 10 min prior to ISO injection (20 mg/kg) followed by exercise abolishes the reduction in latency to fall from the accelerating rotarod in heterozygous mice

• similalry, ATZ significantly decreases the number of hindfoot missteps on the balance beam, induced by ISO and exercise in heterozygous mice

nervous system

abnormal inhibitory postsynaptic currents ( J:82778 )

• in electrophysiological recordings from cerebellar Purkinje cells, heterozygotes display increased frequency and amplitude of spontaneous GABAergic inhibitory postsynaptic currents (IPSCs) relative to wild-type littermates

• however, no significant differences are observed in the amplitude or frequency of miniature IPSCs and the basket cell firing frequency relative to wild-type mice

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
episodic ataxia type 1		DOID:0050989	OMIM:160120	J:82778