When, where, and how much? Expression of the Kv3.1 potassium channel in high-frequency firing neurons.

The Kv3.1 potassium channel gene is expressed in neurons that fire action potentials at high frequencies. Neurons that express this gene, such as auditory brain stem neurons, have high-threshold voltage-dependent potassium currents that activate and deactivate unusually rapidly, and whose characteristics match those of the Kv3.1 subunit expressed heterologously. The level of Kv3.1 expression in neurons is regulated during development and by environmental stimuli. Pharmacological and computer modeling studies indicate that changes in the level of this channel alter the ability of a neuron to follow synaptic inputs at high frequencies. To understand the transcriptional mechanisms that control Kv3.1 expression, an initial characterization of the primary promoter for the Kv3.1 gene was carried out. This review summarizes current knowledge regarding Kv3.1 gene transcription and the roles of upstream regulatory elements in conferring cell-type specificity and long-term regulation by extrinsic factors.