Developmental changes of the mitochondria in the murine anteroventral cochlear nucleus
Anika Hintze,
Felix Lange,
Anna M. Steyer,
Jannis Anstatt,
Wiebke Möbius,
Stefan Jakobs,
Carolin Wichmann
Affiliations
Anika Hintze
Molecular Architecture of Synapses Group, Institute for Auditory Neuroscience, InnerEarLab and Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, 37075 Göttingen, Germany
Felix Lange
Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany; Clinic of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany
Anna M. Steyer
Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, 37075 Göttingen, Germany; Electron Microscopy-City Campus, Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, 37075 Göttingen, Germany
Jannis Anstatt
Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany; Clinic of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany
Wiebke Möbius
Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, 37075 Göttingen, Germany; Electron Microscopy-City Campus, Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, 37075 Göttingen, Germany
Stefan Jakobs
Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany; Clinic of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany; Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, 37075 Göttingen, Germany; Translational Neuroinflammation and Automated Microscopy, Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Göttingen, Germany; Corresponding author
Carolin Wichmann
Molecular Architecture of Synapses Group, Institute for Auditory Neuroscience, InnerEarLab and Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, 37075 Göttingen, Germany; Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, 37075 Göttingen, Germany; Corresponding author
Summary: Mitochondria are key organelles to provide ATP for synaptic transmission. This study aims to unravel the structural adaptation of mitochondria to an increase in presynaptic energy demand and upon the functional impairment of the auditory system. We use the anteroventral cochlear nucleus (AVCN) of wild-type and congenital deaf mice before and after hearing onset as a model system for presynaptic states of lower and higher energy demands. We combine focused ion beam scanning electron microscopy and electron tomography to investigate mitochondrial morphology. We found a larger volume of synaptic boutons and mitochondria after hearing onset with a higher crista membrane density. In deaf animals lacking otoferlin, we observed a shallow increase of mitochondrial volumes toward adulthood in endbulbs, while in wild-type animals mitochondria further enlarged. We propose that in the AVCN, presynaptic mitochondria undergo major structural changes likely to serve higher energy demands upon the onset of hearing and further maturation.