A UNIGE team has discovered the genetic programs that allow motor neurons to retract from the spinal cord. This discovery opens up prospects for combating neurodegeneration. The motor cortex is made up of neurons responsible for muscle contraction .
These neurons have cellular extensions called axons, which project from the cortex into the spinal cord. During brain development , some of these neurons retract their axons to project, not into the spinal cord, but into the brain. How does this happen? Neuroscientists at the University of Geneva (UNIGE) have discovered that everything is linked to genetic programming.
Indeed, our genes define which parts of the cortex are dedicated to motor functions and which are not, by directing neuronal projections. This fundamental discovery, published in the journal Nature , opens up new avenues for countering motor disorders. The cerebral cortex is the outer part of the brain responsible for higher cognitive functions, such as thinking, perception, decision-making, language and memory.
It also processes sensory information and controls movement. To do this, it dedicates part of its volume to movement: the motor cortex. This is where the neurons responsible for muscle contraction—the corticospinal neurons—project to the spinal cord.
Despite the compartmentalization of the cortex, corticospinal neurons are found outside the motor cortex. Why is this? Selection during development To answer this question, the neuroscientists focused on the.