title: Association of intracellular and synaptic organization in cochlear inner hair cells revealed by 3D electron microscopy.
abstract: The ways in which cell architecture is modelled to meet cell function is a poorly understood facet of cell biology. To address this question, we have studied the cytoarchitecture of a cell with highly specialised organisation, the cochlear inner hair cell (IHC), using multiple hierarchies of three-dimensional (3D) electron microscopy analyses. We show that synaptic terminal distribution on the IHC surface correlates with cell shape, and the distribution of a highly organised network of membranes and mitochondria encompassing the infranuclear region of the cell. This network is juxtaposed to a population of small vesicles, which represents a potential new source of neurotransmitter vesicles for replenishment of the synapses. Structural linkages between organelles that underlie this organisation were identified by high-resolution imaging. Taken together, these results describe a cell-encompassing network of membranes and mitochondria present in IHCs that support efficient coding and transmission of auditory signals. Such techniques also have the potential for clarifying functionally specialised cytoarchitecture of other cell types.
authors.affiliation: Centre for Auditory Research, UCL Ear Institute, London WC1X 8EE, UK a.bullen@ucl.ac.uk.
authors.forename: Anwen
authors.initials: A
authors.lastname: Bullen
authors.affiliation: Centre for Auditory Research, UCL Ear Institute, London WC1X 8EE, UK.
authors.forename: Timothy
authors.initials: T
authors.lastname: West
authors.affiliation: Institute of Structural and Molecular Biology, Birkbeck College, London WC1E 7HX, UK.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Moores
authors.affiliation: Centre for Auditory Research, UCL Ear Institute, London WC1X 8EE, UK Neuroscience, Physiology & Pharmacology, UCL, London WC1E 6BT, UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Ashmore
authors.affiliation: Centre for Ultrastructural Imaging, King's College London, London WC2R 2LS, UK.
authors.forename: Roland A
authors.initials: RA
authors.lastname: Fleck
authors.affiliation: National Institute for Biological Standards and Control, Potters Bar EN6 3QG, UK.
authors.forename: Kirsty
authors.initials: K
authors.lastname: MacLellan-Gibson
authors.affiliation: Centre for Auditory Research, UCL Ear Institute, London WC1X 8EE, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Forge
mesh_terms: D000818:Animals; D006168:Guinea Pigs; D006199:Hair Cells, Auditory, Inner / Q000378:metabolism / Q000648:ultrastructure*; D021621:Imaging, Three-Dimensional; D051379:Mice; D008854:Microscopy, Electron; D009435:Synaptic Transmission / Q000502:physiology; D013572:Synaptic Vesicles / Q000378:metabolism / Q000648:ultrastructure*
keywords: 3D electron microscopy; Inner hair cell; Intracellular membranes; Synapse