Loss of auditory activity modifies the location of potassium channel KCNQ5 in auditory brainstem neurons.
Bottom Line: The results were comparable after intracochlear TTX injection, which drastically reduced KCNQ5 immunostaining in MNTB calyces and increased immunolabeling in VCN cell bodies.Endbulbs of Held in the VCN also showed diminished KCNQ5 labeling after intracochlear TTX injection.These results show that peripheral activity from auditory nerve afferents is necessary to maintain the subcellular distribution of KCNQ5 in synaptic endings of the auditory brainstem.
Affiliation: Instituto de Investigación en Discapacidades Neurológicas (IDINE), Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain.Show MeSH
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Mentions: Fluoro-Jade staining helped determine the time course of fiber degeneration in the CN after bilateral cochlear ablation (Fig. 4A–C). Control sections of the AVCN showed only background fluorescence (Fig. 4A). On days 3, 10, and 40 after cochlear removal, the coronal sections of the CN exhibited degenerated terminal and fiber fields labeled with Fluoro-Jade, which occupied the nerve root and a large area of the CN (Fig. 4B,C). In contrast, cell bodies of CN neurons were not labeled with Fluoro-Jade at either stage (Fig. 4B,C), suggesting that no transneuronal degeneration took place, at least in this experimental time window.
Affiliation: Instituto de Investigación en Discapacidades Neurológicas (IDINE), Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain.