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: Coronal sections at the AVCN and MNTB levels (Fig. 2A) were analyzed. In the AVCN of control animals, there were numerous bouton-like structures corresponding to the synaptic endings labeled for KCNQ5 (Fig. 2B). The AVCN sections from animals in which the cochlea had been removed at P30 displayed a loss of immunoreactive endings around cell bodies starting on day 3 and continuing to day10 after surgery, probably as a result of axonal degeneration. In these animals, a small number of cells showed a few KCNQ5-stained bouton-like structures around their somata (Fig. 2C). On day 40 following cochlear ablation, the KCNQ5-immunostained endings around AVCN neurons had almost completely disappeared, whereas immunoreactive cell bodies, previously not visible, were seen in the AVCN (Fig. 2D).
Affiliation: Instituto de Investigación en Discapacidades Neurológicas (IDINE), Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain.