Princeton University researchers have found that a family of proteins with important roles in the immune system may be responsible for fine-tuning a person’s motor control as they grow — and for their gradual loss of muscle function as they age. The research potentially reveals a biological cause of weakness and instability in older people, as well as a possible future treatment that would target the proteins specifically.
Princeton University researchers found that proteins in the MHCI, or major histocompatibility complex class I, family may contribute to fine-tuning a person’s motor control as they grow — and also contribute to their gradual loss of muscle function as they age. They found that MHCI proteins “prune” the connections, or synapses, between motor neurons and muscle fibers, which is necessary during early development. This image from a mouse bred to express less MHCI shows two motor neurons (green) still connected to a single muscle fiber (red) at an age when only one connection should remain.
Credit: Image by Lisa Boulanger, Princeton Neuroscience Institute, and Mazell Tetruashvily, Department of Molecular Biology