How neurons stay in place during growth

As the C. elegans worm grows during its adult life, increasing almost a hundred times in size, the neurons that stretch the length of its body grow, too. Until recently, scientists haven’t known what keeps synapses—the junctions between neurons—in their correct positions during this process.

Now, research by Yale scientists offers clues. By screening genetically mutated worms to find animals that maintain synaptic positions incorrectly, a team led by Associate Professor of Cell Biology Daniel A. Colón-Ramos, Ph.D., found that the gene cima-1 is vital for proper synaptic maintenance.

Further experiments revealed that cima-1 encodes a protein found not in neurons themselves, but in epidermal cells. The protein, the team reported in the July 18 issue of Cell, mediates the interactions between epidermal cells and the glial cells that contact neurons at synapses. The finding suggests that glial cell position is vital for maintaining synaptic positions during growth, and could provide clues to how synaptic positions are maintained during growth in humans.