TABLE 2. Estimation of the relative α1, α6, γ2, and δ subunit composition of α6- and δ-containing GABARs in control (+/+) and stargazer (stg) cerebellum.

Cerebella from adult control (+/+) and stg mice were extracted with deoxycholate buffer. Equivalent amounts of extracted protein from each mouse were either incubated with δ or α6 antibodies, and the precipitated proteins were subjected to immunoblotting using digoxigenized α1, α6, γ2, or δ antibodies as probes. Immunoreactive proteins were identified by chemiluminescence, and intensity of protein staining was quantified using Fluor-S multi-imager (Bio-Rad). Since staining efficiency of individual subunit depends on the number of epitopes recognized by the antibodies as well as their avidity, intensity of protein staining cannot be used for direct quantification of subunits. A possible change in the subunit composition of the precipitated receptors can, however, be determined when the signal intensity of the co-precipitated subunit is referred to that of the precipitated subunit in +/+ and stargazer cerebellum. Data are from two experiments performed with two +/+ and two stg mice in duplicate. For statistical comparison unpaired Student’t t test was used (NS indicates not significant, not detected).

δ IP	+/+, % of δ	stg, % of δ	Significance (p value)
δ	100 ± 4	100 ± 2
α6	45 ± 16	40 ± 13	NS
α1	43 ± 8	117 ± 11	<0.05
γ2			NS

α6 IP	% of α6	% of α6
α6	100 ± 3	100 ± 8
α1	151 ± 19	175 ± 12	NS
γ2	114 ± 11	138 ± 16	NS
δ	141 ± 14	133 ± 13	NS