Just like how our friends are by our side in our moments of stress, our body also functions in a similar arrangement. Brain cells called astrocytes, act as “angels in disguise” for injured or struggling nerve cells and send them “gifts” in the form of energy-producing mitochondria. These gifts are especially useful for helping the neurons bounce back after damage caused by heavy issues, such as strokes.
Mitochondria are responsible for the production of energy which in turn powers the cells in the body and have previously been observed to move into the damaged cells in other parts of the body, like lungs, heart and liver. Now the new study is indicative of a similar function in the brain.
The astrocytes, that are star-shaped glial cells, also support the neurons by taking in and discarding their discarded mitochondria. Earlier, only this (mitochondria transfer from neuron to astrocyte) function was known, and now the new “opposite-route” revelation comes as a surprise to the scientists.
Neuroscientists Jarek Aronowski of the University of Texas Health Science Center at Houston and Eng Lo of Massachusetts General Hospital and Harvard Medical School are behind the study. They believe that this discovery may be a step forth to find new ways for protecting the brain from damage.
In the experiment conducted in a lab dish, the scientists found that the Astrocytes produced mitochondria, which were let out into the soup surrounding cells. Neurons were then placed in this dish rich with mitochondria. The neurons, when lacking glucose and oxygen (just like it happens in a stroke) they take in these astrocyte-produced-mitochondria. The neurons helped by the donated energy organelles actually seemed to survive better in the “starved” conditions than those growing in the dishes without the extra mitochondria.
Such activity has also been observed in the brains of mice, where astrocytes placed mitochondria within the stroke-struck neurons. A protein, named CD38, appears to be behind the provision of the energy donations. It is present on the outside of the astrocytes, and in its dysfunctionality, the neurons received lesser mitochondria. This indicates that CD38 may be responsible for detecting distress signals for the astrocytes.