Calcium imaging experiments were performed using the IN Cell Analyzer 6000 (GE Healthcare Life Sciences). Media was removed from each well in the 96 well plate with a volume of 10 μl remaining. To achieve a final volume of 190 μl, 180 μl of HEPES buffer was added to the culture. For liquid handling operations, 10 μ! was removed from the matching well of the reagent plate and added to the 190 μl in the analysis plate. For the addition of KCl, 80 μl of “High KCl” HEPES buffer (i.e., HEPES buffer where Nad was exchanged for Kd for a final Kd concentration of 145 mM) was added to the 200 μl buffer in the analysis plate to yield a final concentration of 41.4 mM. CNO or clozapine were added to the cultures at varying concentrations for comparison. Expression of glutamate receptor AMPA was investigated and CNQX, a commonly used competitive AMPA receptor antagonist, was used to silence activity due to glutamatergic inputs from excitatory neurons in the culture. CNQX was added to the cultures during experiments at a final
