Brown University researchers in Providence, Rhode Island, have identified changes in gene activity that help developing nerve fibres navigate the spinal cord. In a September 16 announcement, the university described a PNAS study linking these changes inside neurons to the guidance of their growing axons. The findings concern mouse development, not a tested treatment for people.
Axons carry connections from neurons to other cells. The team studied commissural neurons, which link the nervous system’s left and right sides. Their axons turn sharply when crossing the spinal cord’s midline, offering a way to examine how growing fibres change direction at intermediate checkpoints.
According to Brown, researchers in Alexander Jaworski’s laboratory used a custom genetic tool to isolate these neurons at four developmental stages. Single-cell RNA sequencing then revealed which genes were active. This approach allowed the team to compare gene activity as the cells developed and their axons advanced.
The analysis linked passage across the midline to a broad change in gene expression. Different guidance molecules appeared at axon tips, helping direct growth toward the next checkpoint. The finding adds a role for gene regulation in the cell body to understanding navigation at the growing tip, according to the university’s account.
The work also produced gene-expression data for more than 12,000 neurons at different developmental stages. Brown said this atlas could support wider spinal cord research. The study’s focus on normal development means it does not establish that the same approach can repair injured adult nerves or restore movement.
Jaworski said the discovery could help researchers investigate how to guide regrowing axons to their correct targets after spinal injury or stroke. How groups of genes work together remains an open question for further study. Brown reported support from the US National Institutes of Health and its Carney Institute for Brain Science.
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