KENBIKYO Vol.49▶No.3 2014

Mitochondrial Network-Structures Visualized with Scanning Electron Microscopy

Tomonori Naguro, Hironobu Nakane, Sumire Inaga, Toshio Kameie and Toshiyuki Kaidoh

Abstract: The three-dimensional structure of mitochondria within the rat’s olfactory-bulb granule cells was investigated using high-resolution scanning electron microscopy (SEM). These mitochondria formed a continuous network. On the basis of their morphological characteristics, the mitochondrial networks were roughly classified into four types. Type-1: Mitochondrial networks are composed of a single branched tubule of almost uniform thickness of about 250-300 nm. Type-2: Mitochondrial networks have two kinds of tubules, about 250-300 nm and 100 nm across. Type-3: Mitochondrial networks are composed of two different parts; globular parts around 1.0 μm in diameter and filamentous parts about 50-100 nm across. Type 4: Highly complex mitochondrial networks consisting of multiple parts of varying shapes. The significance of this morphological diversity of mitochondrial networks is discussed with reference to recent studies involving other techniques, notably light- and transmission electron microscopy while considering the advantages and disadvantages of the SEM methods employed in this study.

Key words: Mitochondria, Granule cell, Olfactory bulb, Electron microscopy, Scanning Electron Microscopy