Gabra4 Conditional Knockout mouse models

Gabra4 encodes the α4 subunit, ortholog of human GABRA4, which partners preferentially with δ rather than γ2 and localizes to extrasynaptic and perisynaptic membranes of dentate granule cells, thalamus and striatum, where α4βδ receptors mediate high-affinity tonic GABA current rather than phasic inhibition. These receptors carry an arginine at the position equivalent to α1 His101, rendering them benzodiazepine-insensitive, while remaining exquisitely sensitive to neurosteroids such as allopregnanolone, to low-dose ethanol, and to the superagonist gaboxadol, which is the pharmacological signature that defines the subunit. Expression is plastic, rising sharply after stress, ethanol withdrawal and across the ovarian cycle, so phenotyping must control for hormonal state. Constitutive nulls are viable and lose gaboxadol-sensitive tonic current, so a conditional null with Pomc-Cre or a dentate driver localizes the contribution, whereas δ subunit deletion produces overlapping phenotypes; measure tonic current amplitude directly rather than inferring from behavior.

A floxed Gabra4 allele paired with Cre gives spatial control that whole body knockouts cannot offer. People use it to separate developmental roles from adult homeostasis, to model somatic mutations, and to match disease that begins in one organ.