Qualitative and quantitative morphology of renal nerves in C57BL/6J mice

Authors

  • Valéria Paula Sassoli Fazan,

    Corresponding author
    1. Department of Surgery and Anatomy, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
    • Department of Surgery and Anatomy, School of Medicine of Ribeirão Preto, USP, Av. Bandeirantes 3900, Ribeirão Preto, SP, Brazil 14049-900
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    • Fax: +55-16-633-0017

  • Xiuying Ma,

    1. Cardiovascular Center, Department of Internal Medicine, University of Iowa, Iowa City, Iowa
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  • Mark W. Chapleau,

    1. Cardiovascular Center, Department of Internal Medicine, University of Iowa, Iowa City, Iowa
    2. Veterans Affairs Medical Center, Iowa City, Iowa
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  • Amilton Antunes Barreira

    1. Department of Neurology and University Hospital, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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Abstract

The detailed morphology of the renal nerves in mice has not been reported previously. The aims of this study were to describe the general morphology of the extrinsic renal nerve in C57BL/6 mice, and determine its morphometric parameters. The major renal nerve innervating the left kidney was isolated in five mice. Thin sections of the nerve segments were then examined by transmission electron microscopy. The renal nerve averaged 35.4 ± 3.6 (S.E.M.) μm in diameter and 741 ± 104 μm in area. The renal nerve contained an average of 830 ± 169 unmyelinated fibers and only 4.6 ± 1.7 myelinated fibers. The axon diameter of myelinated and unmyelinated fibers averaged 2.2 ± 0.3 μm and 0.76 ± 0.02 μm, respectively. The diameter of the unmyelinated fibers ranged from 0.3 to 2.0 μm, and the distribution histogram was unimodal. The majority of fibers (85%) had diameters of 0.6–1.0 μm. These results are similar to those obtained for renal nerves of rats with respect to the predominance of unmyelinated fibers. However, the diameter of unmyelinated fibers is larger in rats and the distribution histogram of rat unmyelinated fibers is bimodal, in contrast to the unimodal distribution in mice. The morphological description of the renal nerves in mice provides baseline data for further investigations of the structural basis of altered autonomic reflexes. The results will be useful in analyses of genes that influence the development and structure of sympathetic and sensory innervation of the kidney in genetically manipulated mice. Anat Rec 268:399–404, 2002. © 2002 Wiley-Liss, Inc.

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