Phenotypes associated with this allele

• Allele Symbol: Gabra4^tm1.1Geh
• Allele Name: targeted mutation 1.1, Gregg E Homanics
• Allele ID: MGI:3691194
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Gabra4^tm1.1Geh/Gabra4^tm1.1Geh	involves: 129S1/Sv * 129X1/SvJ * C57BL/6J * FVB/N	MGI:3692445

Genotype
MGI:3692445

hm1

• Allelic Composition: Gabra4^tm1.1Geh/Gabra4^tm1.1Geh
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ * C57BL/6J * FVB/N

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

behavior/neurological

impaired behavioral response to xenobiotic ( J:115154 )

• mutants are insensitive to the ataxic, sedative, and analgesic effects of a hypnotic drug, gaboxadol

• mutant mice do not display ataxia induced by 10 mg/kg gaboxadol (GBX) and show greatly reduced ataxic response to 15 mg/kg GBX compared to wild-type mice

• treatment with GBX has no significant effect on total locomotor activity in Gabra4-null mice whereas wild-type mice show significantly reduced locomotor activity in response to GBX

decreased thermal nociceptive threshold ( J:115154 )

• after GBX treatment, mutant mice show a slight but significant increase in tail-flick latency compared to baseline, while wild-type mice exhibit a markedly prolonged latency to tail flick compared to baseline

nervous system

abnormal GABA-mediated receptor currents ( J:115154 )

• treatment of hippocampal slices with GABA uptake inhibitor results in concentration-dependent increases in holding current in wild-type, but not mutant preparations

• subsequent application of picrotoxin reduces holding current in wild-type and mutant dentate granule cells (DGCs); this picrotoxin-sensitive, tonic current (I_tonic) is reduced greatly in mutant DGCs

• in ventrobasal thalamic neurons, tonic currents in mutant neurons are not affected by GBX which evokes large inward currents in wild-type neurons; effects of SR95531 and GBX are absent or greatly reduced in mutant neurons compared to wild-type responses

abnormal inhibitory postsynaptic currents ( J:115154 )

• examination of miniature IPSC kinetics under basal conditions reveals marked slowing of the rise and early decay of mIPSCs in mutant DGCs