RT Journal Article SR Electronic T1 Distinct Kv Channel Subtypes Contribute to Differences in Spike Signaling Properties in the Axon Initial Segment and Presynaptic Boutons of Cerebellar Interneurons JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 6611 OP 6623 DO 10.1523/JNEUROSCI.4208-13.2014 VO 34 IS 19 A1 Matthew J. M. Rowan A1 Elizabeth Tranquil A1 Jason M. Christie YR 2014 UL http://www.jneurosci.org/content/34/19/6611.abstract AB The discrete arrangement of voltage-gated K+ (Kv) channels in axons may impart functional advantages in action potential (AP) signaling yet, in compact cell types, the organization of Kv channels is poorly understood. We find that in cerebellar stellate cell interneurons of mice, the composition and influence of Kv channels populating the axon is diverse and depends on location allowing axonal compartments to differentially control APs in a local manner. Kv1 channels determine AP repolarization at the spike initiation site but not at more distal sites, limiting the expression of use-dependent spike broadening to the most proximal axon region, likely a key attribute informing spiking phenotype. Local control of AP repolarization at presynaptic boutons depends on Kv3 channels keeping APs brief, thus limiting Ca2+ influx and synaptic strength. These observations suggest that AP repolarization is tuned by the local influence of distinct Kv channel types, and this organization enhances the functional segregation of axonal compartments.