Abstract
Ca
2+-activated K
+ currents are found in most types of cells. Considerable progress has been made since the development of single channel recording techniques in identifying some of the channels underlying these currents. It is now apparent that there are many types of Ca
2+-activated K
+ channels, which differ in their conductances and sensitivity to activation by both [Ca
2+]
i and voltage. Ca
2+-activated K
+ channels couple Ca
2+ metabolism and membrane potential to K
+ flux and membrane excitability. Ca
2+-activated K
+ channels allow and modulate repetitive firing in some neurons and contribute to regulation of secretion in some endocrine and exocrine cells.
