Muscle cells help the eyes of real vortex worms to be re-born

if the real vortex of fresh water life can grow its eyes again in a few days. How do they do that? This is a problem that Peter Reddien's lab at the Whitehead Institute has been working on for years. Recently, the team has gained some new insights: They have discovered a new type of cell that could act as a road sign to help the worms reconstruct neural circuits from the eye to the brain.
worm can regenerate any part of the body, and the eye is especially a part worth studying. The eyes of a real vortex are made up of photoreceptor neurons that capture light and connect to the brain through axons. As the nervous system develops in the embryo, the first nerve fibers, known as avant-garde axons, meander through the tissue, forming the circuits needed to sense and interpret external stimuli. These axons are helped forward by a special cell called a road sign cell. In many organisms, once the development is complete, these road sign cells are not usually updated in adulthood. That's why when humans experience brain or nerve damage, it's usually permanent.
then, in 2018, Lucilla Scimone of the Reddien Lab found something surprising in adult real vortex: a mysterious group of cells that may have played a role in guiding axon growth.
when the researchers identified the cells, they found that they did not express any genes that characterize neurons in photoreresorns. Instead, they found markers in muscle tissue. In other organisms, road sign cells are usually neurons or glials. It is unusual for muscle cells to act as road signs. But previous studies have shown that real vortex muscle cells also play other special roles, such as secreting extracellular substrings.
researchers have developed an eye transplant that can transplant the eyes of one animal into another. At this point, if the position is right, the axon projection from the eye is basically connected to the brain, creating a functional state.
researchers also created genetically engineered vortex, which have muscle cells but no eyes, and then transplanted them to their eyes. Sure enough, neurons grow normally and adjust their trajectory. But without these cells, it's different. When the researchers transplanted the eye into a vortex body without these muscle cells, the photorereptor neurons were not connected to the center of the brain.
these findings suggest that these cells are completely independent of the visual system - they are not formed by eye or photoreresorn neurons, but may have formed before they grow - providing more evidence of the role of road signs.
study is a step forward in expanding regenerative medicine capabilities. 'Imagine a scenario where someone has experienced a spinal cord injury, eye injury, or stroke that causes the loss of a neural circuit,' the researchers said.
paper information: https://doi.org/10.1126/science.aba3203