A Neuron question. Pls Help?

Question

I need to know this answer for tomorrow. How does the increase of Potassium inhibit the pre-synaptic membrane and affect the Action Potential?

Answer 1

Is the increase of K+ inside the cell or outside it? If it's extracellular, it would decrease the concentration gradient across the cellular membrane, resulting in a decreased flow of potassium out of the cell when the potassium channels are opened. If that flow is reduced enough, the level of depolarization will not be sufficient to reach the threshold level required to trigger an action potential.