Clozapine-N-oxide (CNO) and clozapine were added to microwells containing DREADD-infected excitatory neurons and DREADD-negative excitatory neurons, as a control. CNO doses ranged from 500 nM to a final concentration of 0.8 nM, consistent with previous studies.29,30 Varying concentrations of CNO were added to different plate locations to avoid plate bias. The reagent plate contained CNO concentrations that were 20× the final, due to the 20× dilution in the media after addition (Table 1).