Comparison of electrode impedance measures between a dexamethasone-eluting and standard Cochlear™ Contour Advance® electrode in adult cochlear implant recipients.

Objective: To compare the difference in electrode impedance across discrete time points to 24 months post-activation for two groups of adult cochlear implant recipients, one using an investigational perimodiolar (Contour Advance®) array augmented with 40% concentration weight per weight (w/w) dexamethasone (the Drug Eluting Electrode, 'DEE' Group), and the other the commercially available Contour Advance ('Control' Group).

Design: Ten adult subjects were implanted with the DEE and fourteen with the Control. Electrode impedances were measured intra-operatively, one-week post-surgery, at initial activation (approximately two-weeks post-surgery), and at approximately one, three, six, 12 and 24 months post-activation.

Heteromeric Kv7.2/7.3 channels differentially regulate action potential initiation and conduction in neocortical myelinated axons.

Rapid energy-efficient signaling along vertebrate axons is achieved through intricate subcellular arrangements of voltage-gated ion channels and myelination. One recently appreciated example is the tight colocalization of K(v)7 potassium channels and voltage-gated sodium (Na(v)) channels in the axonal initial segment and nodes of Ranvier. The local biophysical properties of these K(v)7 channels and the functional impact of colocalization with Na(v) channels remain poorly understood.