Answer:
No immediate effect is observed
Explanation:
If you put ouabain, an inhibitor of the Na+-K+ pump, on a neuron and then stimulate the neuron repeatedly, there would be no immediate effect to the action potentials generated by the neuron because Na+ gets stucked inside the cell, the depolarization slope gets steeper, and the duration of the action potential shortens because the membrane potential reaches +30 mV and other voltage-gated channels are opening in the membrane.