Tetraethylammonium (TEA) is a potent neurotoxin that results in death from respiratory failure within 10 to 30 minutes. When a neuron is incubated with TEA, researchers observed that action potentials could be generated, but the membrane potential remained positive and never returned to the resting membrane potential. What channels could be opened that would counter the effects of TEA and allow the neuron to return to resting membrane potential