Credit: ChiaHung Lee et al.
Researchers at the University of California, Irvine and the University of Pennsylvania, recently observed electrical charge and discharge functions within mitochondria. By observing mitochondria membranes in various metabolic states, the researchers observed the electrophysiological functioning of these organelles.
Mitochondria is a cellular structure responsible for adenosine triphosphate generation to provide energy for various processes in living tissues. Researchers have long sought a deeper understanding of mitochondria due to their importance in human health. Previous research endeavors have been limited to the physical characteristics as they exist within living cells. However, in the study published in ACS Nano, researchers used three super-resolution microscopy techniques including Airy microscopy, stimulated emission depletion microscopy, and lattice-structured illumination microscopy to study live extracellular mitochondria.
"When we first started studying isolated mitochondria, we knew they behaved like a battery based on some work from the Tokyo Metropolitan Institute of Gerontology and UCLA, but we could not control them very well inside the cell to probe them," said Peter Burke, UCI professor of electrical engineering and computer science. "Now we can control each individual electrical component and cause it to charge and discharge."
With these techniques, the researchers examined cristae which act as the mitochondrial batteries. Cristae measure around 100 nanometers and with the shortest wavelength of visible light being violet light at 380 nanometers, superresolution microscopes were vital to the research.
"We could observe in detail how each individual part behaved as a single battery, much like how battery packs in drones and cars—which are many smaller batteries—individually combine to power the vehicle," said Burke. "Interestingly, we found that the batteries rearrange themselves when they charge and discharge, a feature not found in regular batteries."
The research confirmed a long-standing theory that mitochondrial structure can be altered by creating or destroying its cristae as the metabolic needs of the cell change. Burke believes the findings could have broad applications in human health. "Once we understand how they create energy, we can start to think of ways to modify this for improving human health and longevity," he said.