Potassium ions(K+),the pivotal cations for membrane potential,are particularly important for maintaining the physiological function of neurons[1].When the concen-tration of extracellular K+([K+]o)is pathologically changed,the intrinsic neuronal excitability and synaptic transmission are also altered,which have profound impli-cations for many neurological disorders such as epilepsy,Parkinson's disease,and emotional disorders[2-4].