Researchers use photosynthetic microbes as an oxygen source for nerve cells

Each second, the nerve cells in the brain process numerous signals. And the energy needed to carry out these tasks is mostly generated by aerobic metabolism—the reason why the brain needs a constant supply of oxygen.

Image Credit: Giovanni Cancemi/Shutterstock.com

Animals get their oxygen from the environment while photosynthetic organisms have the capability to produce it themselves with the help of sunlight as an energy source. A team of researchers headed by LMU neurobiologist Hans Straka and LMU molecular plant scientist Jörg Nickelsen recently demonstrated that photosynthetic microbes can be employed directly to provide oxygen to the brain. The study was published in the journal iScience.

The scientists introduced photosynthetic microbes—unicellular green algae and cyanobacteria—into the blood vessels of tadpoles of the clawed frog Xenopus laevis, a well-known experimental model. The brains were exposed to light and the measurements of oxygen levels in the ventricles of the tadpole brain showed significant amounts of oxygen were being produced.

Conversely, in an oxygen-poor medium, nerve-cell activity came to a complete halt in darkness. When the light was turned on again, the micro-organisms generated oxygen, and the neurons restarted firing. So, the oxygen generated by photosynthesis is indeed utilized to rescue neuronal activity.”

Hans Straka, Neurobiologist, Ludwig-Maximilians-Universität München

The scientists say that these proof-of-principle experiments reveal that unicellular photosynthetic microbes can serve as new ways of enhancing the supply of oxygen to tissues in a controlled manner. They can be employed to improve oxygen levels in explanted organs, cell cultures, or brain slices.

Furthermore, photosynthetic organisms produce not only oxygen, but also sugars, for example. So it’s conceivable that their metabolic pathways could be exploited to synthesize nutrients as well.”

Hans Straka, Neurobiologist, Ludwig-Maximilians-Universität München

As it is possible to control the duration, intensity, and spectrum of light with utmost accuracy, the technique can also provide novel approaches to the analysis of the role of oxygen in metabolic mechanisms.