Photosynthesizing algae injected into the blood vessels of tadpoles
supply oxygen to their brains

Date:
October 13, 2021
Source:
Cell Press
Summary:
Leading a double life in water and on land, frogs have many
breathing techniques -- through the gills, lungs, and skin --
over the course of their lifetime. Now scientists have developed
another method that allows tadpoles to 'breathe' by introducing
algae into their bloodstream to supply oxygen. The method provided
enough oxygen to effectively rescue neurons in the brains of
oxygen-deprived tadpoles.



FULL STORY ========================================================================== Leading a double life in water and on land, frogs have many breathing techniques -- through the gills, lungs, and skin -- over the course of
their lifetime. Now German scientists have developed another method that
allows tadpoles to "breathe" by introducing algae into their bloodstream
to supply oxygen. The method developed, presented October 13 in the
journal iScience, provided enough oxygen to effectively rescue neurons
in the brains of oxygen- deprived tadpoles.


==========================================================================
"The algae actually produced so much oxygen that they could bring the
nerve cells back to life, if you will," says senior author Hans Straka
of Ludwig- Maximilians-University Munich. "For many people, it sounds
like science fiction, but after all, it's just the right combination
of biological schemes and biological principles." Straka was studying
oxygen consumption in tadpole brains of African clawed frogs (Xenopus
laevis) when a lunch conversation with a botanist sparked an idea to
combine plant physiology with neuroscience: harnessing the power of photosynthesis to supply nerve cells with oxygen. The idea didn't seem
far- fetched. In nature, algae live harmoniously in sponges, corals,
and anemones, providing them with oxygen and even nutrients. Why not in vertebrates like frogs? To explore the possibility, the team injected
green algae (Chlamydomonas renhardtii) or cyanobacteria (Synechocystis)
into tadpoles' hearts. With each heartbeat, the algae inched through
blood vessels and eventually reached the brain, turning the translucent
tadpole bright green. Shining light on these tadpoles prompted both
algae species to pump out oxygen to nearby cells.

After distributing algae to the brain, the researchers isolated the
tadpole's head and placed it in an oxygen bubble bath with essential
nutrients that would preserve the functioning of the cells, allowing the
team to monitor neural activity and oxygen levels. As the researchers
depleted oxygen from the bath, the nerves ceased firing and fell
silent. However, illuminating the tadpole head restarted the neural
activity within 15 to 20 minutes, which is about two times faster than replenishing the bath with oxygen without the algae. The revived nerves
also performed as well or even better than before oxygen depletion,
showing that the researchers' method was quick and efficient.

"We succeeded in showing the proof of principle experiment with this
method. It was amazingly reliable and robust, and in my eyes, a beautiful approach," says Straka. "Working in principle doesn't really mean that
you could apply it at the end, but it's the first step in order to
initiate other studies." While the researchers think their findings
may someday lead to new therapies for conditions induced by stroke or oxygen-scarce environments, such as underwater and high altitudes, algae
are far from ready to enter our blood circulation. The team's next step
is to see whether the injected algae can survive inside living tadpoles
and continue oxygen production without causing an immune response that
wreaks havoc on the animals.

Straka also envisions his research benefiting other laboratories that
work with isolated tissues or organoids. Introducing oxygen-producing
algae could help these tissues thrive and raise their survival rates, potentially reducing the need for live animals for experiments.

"You have to have new ideas and new concepts to explore; this is one of
the ways science is driven," says Straka. "If you are open-minded and
think it through, all of a sudden, you can see all the possibilities
from one idea." This work was supported by German Science Foundation,
the German Federal Ministry of Education and Research, and the Munich
Center for Neuroscience.

========================================================================== Story Source: Materials provided by Cell_Press. Note: Content may be
edited for style and length.


========================================================================== Journal Reference:
1. Green oxygen power plants in the brain rescue neuronal
activity. Green
oxygen power plants in the brain rescue neuronal activity. iScience,
2021 DOI: 10.1016/j.isci.2021.103158 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/10/211013114031.htm

--- up 5 weeks, 6 days, 8 hours, 25 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)