Biologists at the University of Bayreuth have discovered a form of exceptionally rapid regeneration in injured neurons and its function in the central nervous system of zebrafish. The scientists have published their findings in the magazine Communications Biology.
In the central nervous systems of other animal species, such complete regeneration of neurons has not yet been definitively demonstrated.
Mauthner cells
The Mauthner cells They are the largest cells found in the brains of animals. They are part of the central nervous system of most species of fish and amphibians and trigger life-saving escape responses when predators approach.
The transmission of signals in the Mauthner cells to their motoneurons is only guaranteed if a certain part of these cells, the axon, is intact. The axon is an elongated structure that limits the cell body with its cell nucleus at one of its two ends. If the axon injury occurs near the cell body, Mauthner cell dies. If the axon is damaged at its opposite end, the lost functions are not restored at all or only slowly and to a limited extent.
However, the Mauthner cell reacts to an injury in the middle of the axon with rapid and complete regeneration. In fact, within a week after injury, the axon and its function are completely restored, and the fish can again escape from approaching predators.
It might be possible that other neurons in zebrafish can induce this life-saving escape behavior and thus take over the lost function of Mauthner cells. However, precisely this possibility was ruled out by previously published findings. According to one of the lead researchers, Hecker:
Mauthner cells now offer us the possibility of investigating very different responses to injury of individual cells within the same nervous system: an absence or insufficient regenerative processes on the one hand, and robust and complete regeneration on the other. Surprisingly, lesions to the axon, which led to such contradictory responses, were not far away. Elucidating the causes is an exciting field of research, which also includes identifying the genes that are active in neuronal regeneration. And if we discover why regeneration processes in Mauthner cells do not occur, we could also better understand the mechanisms that prevent the regeneration of neurons in humans.
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The news
An exceptionally rapid form of regeneration is discovered in injured neurons
was originally published in
Xataka Science
by
Sergio Parra
.