Experimental Approach
Human neurons were differentiated from two induced pluripotent stem cell (hiPSC) lines. P2X7R function on neurons was assessed via P2X7R agonist BzATP-evoked calcium transients. Acute or chronic in vitro models of epileptiform-like events were generated by exposure of hiPSC cultures to the GABAA receptor antagonist picrotoxin or a cocktail of picrotoxin and neuroinflammatory agents with or without the presence of P2X7R antagonists. Epileptiform-like activity was measured via single cell patch-clamp recordings.

Key Results

BzATP application (300 µM) resulted in increased calcium influx in hiPSC-derived neurons which was blocked by the P2X7R antagonists JNJ-47965567 (100 nM) and AFC-5128 (30 nM). Single-cell patch-clamp recordings showed that, while treatment with AFC -5128 did not reduce epileptiform-like activity triggered by picrotoxin alone,AFC -5128 reduced the severity of epileptiform-like activity under inflammatory conditions. Notably, epileptiform-like events in the inflammation-primed picrotoxin model were refractory to the anti-seizure medication carbamazepine alone but were reduced by the co-application of carbamazepine with AFC -5128.