Glia and the regulation of extracellular potassium concentration in the CNS

Through this mechanism, glia participate in information transmission in the CNS and ion balance:
 * during action potential, potassium enters the extracellular space,
 * an increase in extracellular potassium leads to long-lasting depolarization of neurons (suppresses nerve activity).

Removal of increased concentration of potassium (extracellular):
 * diffusion,
 * influx of potassium into glial cells,
 * active transport of potassium into the neuron.

Other mechanisms of potassium homeostasis:
 * transmembrane Na+ cycle,
 * transfer of KCl (absorption),
 * Ca2+/K+ interactive system.

The movement of potassium into glia is referred to as spatial buffering. Glia are connected by gap junctions (ion movement is not restricted)

Related Articles

 * Action potential (physiology)
 * Membrane potential and its changes