Altered muscle electrical tissue properties in a mouse model of premature aging

Muscle Nerve. 2019 Dec;60(6):801-810. doi: 10.1002/mus.26714. Epub 2019 Oct 30.


Introduction: Improved methods are needed to detect and quantify age-related muscle change. In this study we assessed the electrical properties of muscle impacted by acquired mitochondrial DNA mutations via the PolG mouse, which exhibits typical age-associated features, and the impact of a potential therapy, nicotinamide mononucleotide (NMN).

Methods: The gastrocnemii of 24 PolG and 30 wild-type (WT) mice (8 PolG and 17 WT treated with NMN) were studied in an electrical impedance-measuring cell. Conductivity and relative permittivity were determined from the impedance data. Myofiber cross-sectional area (CSA) was quantified histologically.

Results: Untreated PolG mice demonstrated alterations in several impedance features, including 50-kHz relative permittivity and center frequency. A potential effect of NMN was also observed in these parameters in PolG but not WT animals. Impedance values correlated with myofiber CSA.

Discussion: Electrical impedance is sensitive to myofiber features considered characteristic of aging and to the impact of a potential therapy.

Keywords: Aging; Impedance; Mitochondrial disorder; Muscle; Myofiber; Nicotinamide mononucleotide.

Publication types

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

MeSH terms

  • Aging, Premature / pathology
  • Aging, Premature / physiopathology*
  • Animals
  • Cell Size
  • DNA Polymerase gamma / genetics
  • DNA, Mitochondrial / genetics
  • Disease Models, Animal
  • Electric Impedance
  • Gene Knock-In Techniques
  • Mice
  • Muscle Fibers, Skeletal / drug effects
  • Muscle Fibers, Skeletal / pathology*
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / pathology
  • Muscle, Skeletal / physiopathology*
  • Mutation
  • Myography / methods
  • Nicotinamide Mononucleotide / pharmacology


  • DNA, Mitochondrial
  • Nicotinamide Mononucleotide
  • DNA Polymerase gamma
  • Polg protein, mouse