To investigate pharmacological effects, synaptic antagonists were directly added to the MEA wells containing hNGN2-neurons. The GABAA receptor antagonist picrotoxin (PTX) (Tocris #1128), the AMPA/kainate receptor antagonist 6-cyano-7-nitroqui noxaline-2,3-dion (CNQX) (Alomone labs, #C-140) and sodium ion/channel antagonist tetrodotoxin (TTX) (Alomone labs, #T-550) were used at final concentration of 100 μM, 60 μM and 1 μM, respectively. Spontaneous recordings were obtained for 3–5 min before and after drug administration (Fig. 6C).
