Source: University of California - San Diego
Date: August 3, 2009
Summary:
In a major step in spinal cord injury research, scientists at the University of California, San Diego School of Medicine have demonstrated that regenerating axons can be guided to their correct targets and re-form connections after spinal cord injury. Their findings will be published in the advance online edition of the journal Nature Neuroscience on August 2.
The UC San Diego study looked at regenerating sensory axons in rat models of spinal cord injury. Sensory systems of the body send axons – long, slender projections of the neuron – into the spinal cord to convey information regarding touch, position, and pain. Many sensory axons are covered by an insulating myelin sheath which helps these impulses travel efficiently to the brain.
The UC San Diego scientists showed that regenerating axons can be guided to correct targets using a type of chemical hormone called a growth factor. The team utilized a type of chemical hormone, a nervous system growth factor called neurotrophin-3 (NT-3), to guide regenerating sensory axons to the appropriate target and support synapse formation. Regeneration required two other treatments at the same time: placing a cell bridge in the spinal cord injury site to support axon growth, and a “conditioning” stimulus to the injured neuron that turned on regeneration genes for new growth.
