3D neuronal mitochondrial morphology in axons, dendrites, and somata of the aging mouse hippocampus

Cell Rep. 2021 Aug 10;36(6):109509. doi: 10.1016/j.celrep.2021.109509.

Abstract

The brain's ability to process complex information relies on the constant supply of energy through aerobic respiration by mitochondria. Neurons contain three anatomically distinct compartments-the soma, dendrites, and projecting axons-which have different energetic and biochemical requirements, as well as different mitochondrial morphologies in cultured systems. In this study, we apply quantitative three-dimensional electron microscopy to map mitochondrial network morphology and complexity in the mouse brain. We examine somatic, dendritic, and axonal mitochondria in the dentate gyrus and cornu ammonis 1 (CA1) of the mouse hippocampus, two subregions with distinct principal cell types and functions. We also establish compartment-specific differences in mitochondrial morphology across these cell types between young and old mice, highlighting differences in age-related morphological recalibrations. Overall, these data define the nature of the neuronal mitochondrial network in the mouse hippocampus, providing a foundation to examine the role of mitochondrial morpho-function in the aging brain.

Keywords: 3D reconstruction; SBF-SEM; aging; hippocampus; microscopy; mitochondria; morphology; morphometry; three-dimensional; topology.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / physiology*
  • Animals
  • Axons / physiology*
  • CA1 Region, Hippocampal / physiology
  • Dendrites / physiology*
  • Dentate Gyrus / physiology
  • Female
  • Hippocampus / physiology*
  • Imaging, Three-Dimensional
  • Mice, Inbred C57BL
  • Mitochondria / metabolism*
  • Neurons / cytology*
  • Subcellular Fractions / metabolism