Why does increased extracellular potassium around a neuron cause hyperexcitability?

💡 Explanation

Increased extracellular potassium reduces the potassium concentration gradient across the neuronal membrane, which reduces potassium efflux. Because the resting membrane potential is more depolarized, the neuron is closer to the threshold for firing an action potential; therefore, hyperexcitability results, rather than hyperpolarization.

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