Expression and differential distribution of the shaker-related voltage-gated potassium channel family (KV1.x) in human hippocampus and neocortex

Abstract

Background All excitable cells express voltage-gated potassium (KV) channels; in neurons they play an essential role in setting the resting membrane potential, controlling the firing frequency and duration of action potentials, and modulate neurotransmitter release. Due to this critical function as regulators of neuronal excitability, mutations and/or deletions in potassium channel subunit genes are associated with diverse clinical phenotypes (channelopathies), including seizure or movement disorders in both humans and animals. Additionally, voltage-gated potassium channels might play a crucial role in neurodegenerative and psychiatric disorders. For this reason, a better understanding of the occurrence and specific distribution of voltagegated potassium channels would be highly necessary. Several members of the KV1 subfamily have been found, but only KV1.1, KV1.2, KV1.4 and KV1.6 are widely expressed in the CNS in both human and rodent brain. However, unlike to rodents, little is known regarding the regional localization of these four members of the KV1 subfamily in human brain. Therefore we investigated, for the first time, the distribution of these four KV1 channel subtypes in human neocortex and hippocampus, which are known for their vulnerability to epilepsy and their importance for learning, memory and cognitive processes.