Mediates voltage-dependent potassium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. The channel activity is up-regulated by cAMP (By similarity). Homotetramer. Detected in brain, cochlear sensory epithelium, cochlear ganglion, tegumentum vasculosum. Detected at low levels in cochlear lagena. First detected at very low levels at embryonic day 6. Detected at embryonic day 9 and 14, and 3 days after hatching. The N-terminus may be important in determining the rate of inactivation of the channel while the tail may play a role in modulation of channel activity and/or targeting of the channel to specific subcellular compartments. The segment S4 is probably the voltage-sensor and is characterized by a series of positively charged amino acids at every third position. Belongs to the potassium channel family. A (Shaker) (TC 1.A.1.2) subfamily. Kv1.8/KCNA10 sub-subfamily.