Panx1 channels promote both anti- and pro-seizure-like activities in the zebrafish via p2rx7 receptors and ATP signaling

The molecular mechanisms of excitation-inhibition imbalances promoting seizure generation in epilepsy patients are not fully understood. Experimental evidence suggests that Pannexin1 (Panx1), an ATP release channel, modulates excitability of the brain. In this report, we have performed behavioral and molecular phenotyping experiments on zebrafish larvae bearing genetic or pharmacological knockouts of panx1a or panx1b channels, each highly homologous to human PANX1. When Panx1a function is lost or both channels are under pharmacological blockage, treatment with pentylenetetrazol to induce seizures causes reduced ictal-like events and seizure-like locomotion. These observations were extended by transcriptome profiling, where a spectrum of distinct metabolic and cell signaling states correlates with the loss of panx1a. The pro- and anticonvulsant activities of both Panx1 channels affects ATP release and involves the purinergic receptor p2rx7. We propose that Panx1 zebrafish models offer opportunities to explore the molecular and physiological basis of seizures and assist anticonvulsant drug discovery.