What is the relationship between chloride influx and action potential generation in zuranolone's mechanism?

• A. More chloride influx leads to decreased action potentials
• B. More chloride influx leads to increased action potentials
• C. Chloride influx has no effect on action potentials
• D. Chloride efflux leads to decreased action potentials

Answer: (A)

The key idea is that increasing chloride influx through GABA_A receptor channels makes the neuron more negatively charged and less excitable. Zuranolone enhances the effect of GABA on these receptors, boosting Cl- conductance when GABA is present. As more Cl- enters, the membrane hyperpolarizes, moving further from the threshold needed to trigger an action potential. That reduced excitability means fewer action potentials occur. So more chloride influx leads to decreased action potential generation. (Chloride efflux or no effect would not produce the same inhibitory outcome in this context.)