Scientists who dream of a future in which regenerative medicine has advanced enough to enable repairs in human nervous systems currently have more questions than answers. As a recently named Searle Scholar, MIT Assistant Professor Brady Weissbourd will seek to learn some of the needed fundamentals by studying a master of neural regeneration: the jellyfish, Clytia hemisphaerica.
Weissbourd, a faculty member in the Department of Biology and The Picower Institute for Learning and Memory, has helped to pioneer use of the seafaring species in neuroscience research for many reasons. It is transparent for easy imaging, reproduces rapidly, and shares many basic nervous system properties with mammals despite diverging evolutionarily 600 million years ago (just after the development of the earliest nervous systems). Meanwhile, with about 10,000 neurons, the jellyfish fills a gap in the field in terms of that degree of complexity.
But what Weissbourd didn’t appreciate until he began experimenting with the jellyfish was that they are also incredibly good at refreshing and rebuilding their nervous systems with new cells. After becoming the first researcher to develop the ability to genetically manipulate the organism, he started teasing out how its highly distributed nervous system (there is no central brain), was organized to enable its many behaviors. When he ablated a subnetwork of cells to test whether it was indeed responsible for a particular feeding behavior, he found that within a week it had completely regrown. Moreover, he has observed that the jellyfish constantly produce and integrate new cells, even in the absence of major injury.
