Tonotopic Differentiation of Coupling between Ca2+ and Kv1.1 Expression in Brainstem Auditory Circuit

• Published in: iScience Vol. 13; pp. 199 - 213
• Main Authors: Adachi, Ryota, Yamada, Rei, Kuba, Hiroshi
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 29.03.2019; Elsevier
• Subjects: Cellular Neuroscience; Molecular Neuroscience; Neuroscience; Molecular Neuroscience; Neuroscience; Cellular Neuroscience
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2019.02.022

Tonotopic differentiations of ion channels ensure sound processing across frequencies. Afferent input plays a critical role in differentiations. We demonstrate here in organotypic culture of chicken cochlear nucleus that expression of Kv1.1 was coupled with Ca2+ to a different degree depending on tonotopic regions, thereby differentiating the level of expression within the nucleus. In the culture, Kv1.1 was down-regulated and not differentiated tonotopically. Chronic depolarization increased Kv1.1 expression in a level-dependent manner. Moreover, the dependence was steeper at higher-frequency regions, which restored the differentiation. The depolarization increased Kv1.1 via activation of Cav1 channels, whereas basal Ca2+ level elevated similarly irrespective of tonotopic regions. Thus, the efficiency of Ca2+-dependent Kv1.1 expression would be fine-tuned in a tonotopic-region-specific manner, emphasizing the importance of neuronal tonotopic identity as well as pattern of afferent input in the tonotopic differentiation of the channel in the auditory circuit. [Display omitted] •Kv1.1 expression is down-regulated in slice culture of chicken cochlear nucleus•Depolarization up-regulates Kv1.1 in a tonotopic-region-specific manner•Level of Kv1.1 expression is dependent on basal calcium concentration•Efficiency of calcium-dependent Kv1.1 expression is differentiated tonotopically Neuroscience; Cellular Neuroscience; Molecular Neuroscience