iN cultures were fixed for 30 min in ice cold methanol and permeabilized using 0.2% Triton X-100 in PBS for 15 min at room temperature. Cells were then incubated in blocking buffer (5% BSA with 5% normal goat serum in PBS) for 30 min at room temperature and then incubated with primary antibodies diluted in blocking buffer overnight at 4 °C, washed with PBS three times, and incubated with secondary antibodies for 1 h at room temperature. Confocal imaging was performed using a Zeiss LSM700. Primary antibodies used: rabbit anti-GIRK2 (Alomone labs, APC-006, 1:400), mouse anti-βIII-tub (BioLegend, MMS-435P,1:1000), chicken anti-MAP2 (Millipore AB5543, 1:1000), mouse anti-Syn1 (SYSY,106-011, 1:200), mouse anti-PSD 95 (SYSY, 124-011, 1:2000), mouse anti-mCherry (Thermofisher Scientific, M11217, 1:100).
