POTASSIUM CHANNELS
Potassium channels can be separated into many different types, such as voltage-dependent, voltage-independent, HERG-like, G-protein-activated , Calcium-activated, inward rectifier and delayed rectifier channels. These channels are regulated by exposure to lipopolysaccharide or various cytokines, activation of protein kinase C or G proteins, changes in concentration of internal free Ca2+ and by variations in pH.

The different subtypes perform distinct functions within the system. For example a voltage-independent channel like TASK is very sensitive to small variations in extracellular pH, ranging from 90% of the maximal activity at pH7.7 to 10% at pH6.7. Calcium activated potassium channels (KCa), such as Maxi-K/BKCa, aid in relaxation of cerebral arteries and arterioles. Inward rectifying coupled with delayed rectifying K+ channels aid in the removal and redistribution of excess K+ in the brain, a process known as "spatial buffering". Alterations of some of these channels factor in such diseases as hypertension, diabetes and atherosclerosis.