Mоdule 4 A phаrmаceuticаl researcher is testing a new drug, NeurоBlоck, designed to treat chronic pain by blocking voltage-gated potassium (K⁺) channels in neurons. During clinical trials, some participants report prolonged muscle contractions, twitching, and difficulty relaxing their muscles after movement. The researcher suspects that the drug is interfering with normal action potential repolarization and disrupting nerve signaling. Explain how a neuron at rest maintains its resting membrane potential. In your response, describe the role of the sodium-potassium pump and leakage channels in maintaining the charge difference across the membrane. Describe the sequence of events in a normal action potential, including the roles of voltage-gated channels in depolarization, repolarization, hyperpolarization, and the refractory period. How would blocking voltage-gated potassium channels affect action potential generation and recovery? Explain why neurons exposed to NeuroBlock might cause prolonged muscle contractions and difficulty relaxing.