HEK293T cells were grown to 70% to 80% confluence and transfected using reagent (Gene Porter; Gene Therapy Systems, San Diego, CA) according to the manufacturer’s protocols. Cells were transfected with approximately 5 μg total DNA (α11.2, 2 μg; β2A, 0.8 μg; α2δ, 0.8 μg; ± CaBP5, 0.1 μg) and GFP expression plasmid (0.01 μg) for fluorescence detection of transfected cells. All electrophysiological data were acquired with EPC-9 patch-clamp amplifier driven by HEKA software (Pulse; HEKA Elektronik, Lambrecht/Pfalz, Germany) and were analyzed with Wavemetrics software (Igor Pro; Wavemetrics, Lake Oswego, OR). Extracellular recording solutions contained 150 mM Tris, 1 mM MgCl2, and 10 mM CaCl2. Intracellular solutions consisted of 140 mM N-methyl-d-glucamine, 10 mM HEPES, 2 mM MgCl2, 2 mM Mg-ATP, and 5 mM EGTA. The pH of intracellular and extracellular recording solutions was adjusted to 7.3 with methane sulfonic acid. Electrode resistances were typically 1 to 2 MΩ in the bath solution, and series resistance was approximately 2 to 4 MΩ, compensated up to 80%. All averaged data are presented as the mean ± SEM. Statistical significance of differences between two groups was determined by Student’s t-test, as indicated (SigmaPlot; SPSS Inc.).