TY - JOUR T1 - Physiological Maturation of Photoreceptors Depends on the Voltage-Gated Sodium Channel Na<sub>V</sub>1.6 (<em>Scn8a</em>) JF - The Journal of Neuroscience JO - J. Neurosci. SP - 5046 LP - 5050 DO - 10.1523/JNEUROSCI.4692-04.2005 VL - 25 IS - 20 AU - Patrice D. Côté AU - Yves De Repentigny AU - Stuart G. Coupland AU - Yannick Schwab AU - Michel J. Roux AU - S. Rock Levinson AU - Rashmi Kothary Y1 - 2005/05/18 UR - http://www.jneurosci.org/content/25/20/5046.abstract N2 - Voltage-gated sodium channels (VGSCs) ensure the saltatory propagation of action potentials along axons by acting as signal amplifiers at the nodes of Ranvier. In the retina, activity mediated by VGSCs is important for the refinement of the retinotectal map. Here, we conducted a full-field electroretinogram (ERG) study on mice null for the sodium channel NaV1.6. Interestingly, the light-activated hyperpolarization of photoreceptor cells (the a-wave) and the major “downstream” components of the ERG, the b-wave and the oscillatory potentials, are markedly reduced and delayed in these mice. The functional deficit was not associated with any morphological abnormality. We demonstrate that Scn8a is expressed in the ganglion and inner nuclear layers and at low levels in the outer nuclear layer beginning shortly before the observed ERG deficit. Together, our data reveal a previously unappreciated role for VGSCs in the physiological maturation of photoreceptors. ER -