by Sasha Nimmo

Mitochondria’s electrical system may explain exercise intolerance in ME.

New 3D microscopic images of mice show how mitochondria are arranged in muscle and now explain how muscle rapidly distributes energy into the cell for movement. Researchers believe the information will change the way scientists think about muscle function and open up a new area to explore in health and disease.

Scientists are reporting the first clear evidence that muscle cells distribute energy primarily by the rapid conduction of electrical charges through a vast, interconnected network of mitochondria — the cell’s “powerhouse” — in a way that resembles the wire grid that distributes power throughout a city. (NIH)

Mitochondrial dysfunction is one of the abnormalities in ME. In future, these findings mean scientists may use muscle biopsies or non-invasive imaging techniques to determine how defects in mitochondrial networks impact diseases.

The study looked at the distribution system that rapidly provides energy throughout the cell where it is needed for muscle contraction. Scientists used probes to prove that the mitochondrial “wires” were electrically conductive.

“Structurally, the mitochondria are arranged in such a way that permits the flow of potential energy in the form of the mitochondrial membrane voltage throughout the cell to power ATP production and subsequent muscle contraction, or movement. Mitochondria located on the edges of the muscle cell near blood vessels and oxygen supply are optimized for generating the mitochondrial membrane voltage, while the interconnected mitochondria deep in the muscle are optimized for using the voltage to produce ATP,” Dr Balaban explained. (NIH)

The research was conducted at the National Heart, Lung, and Blood Institute (NHLBI) and the National Cancer Institute (NCI) at the National Institutes of Health in Bethesda, Maryland. Originally, the ways of imaging were developed to look at HIV-1 infection and structural changes in melanoma cells.

This study appeared in Nature and you can listen to their 5 minute interview with the Dr Balaban.

The full paper is “Mitochondrial reticulum for cellular energy distribution in muscle”.

What is your opinion? Mitochondria and cellular energy production may be closely linked with exercise intolerance, do you think this information could help us understand why?