Authors
Hintze A, Lange F, Steyer AM, Anstatt J, Möbius W, Jakobs S, Wichmann C
Journal
iScience
Citation
iScience. 2023 Dec 8;27(1):108700.
Abstract
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 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 accompanied by a higher abundance of crista membranes. In deaf animals lacking otoferlin, we found only a shallow increase of mitochondrial volumes towards adulthood, while in wild-type mitochondria further enlarged. We propose that in the AVCN, presynaptic mitochondria undergo major structural changes likely to serve higher energy demands after the onset of hearing and during further maturation.