A young Ottawa-based researcher thinks she may have found something that would help adult brains repair themselves:
Her experiments, which build on the growing understanding of how a baby’s brain is different from that of an adult, could lead to novel therapies for brain or spinal cord injuries.
Until about the age of two, the neurons in the human brain are still growing, stretching out long arms known as axons to form connections and build networks and circuits. After that, experience and learning shape those connections largely through pruning, said Dr. Smith, now 32 and running her own lab at Carleton University. Superfluous connections are trimmed; those used more frequently are strengthened in a variety of ways that don’t involve the growth of axons.
This suggests that a mechanism must kick in during the toddler years to prevent neurons from growing and forming new connections, said Dr. Smith, who moved back to Canada in 2008 after doing post-doctoral work at Harvard University.
“There are signals from the brain saying, ‘Okay, the connections are formed, there is no need for you to grow.’ ”
Dr. Smith suspects this could be what prevents injured neurons in the brains and spinal cords of adults from repairing themselves.
Now, she and colleagues at Harvard have a found a molecule that appears to put the brakes on neuron growth in adult mice.
It is called SOCS3. When the scientists blocked it in adult mice with crushed optic nerves, the damaged neurons began to sprout.
Some of the new growth reached as far as the brain. The next step is to see if this is enough to restore the vision of the blind mice, said Dr. Smith, who reported her findings Thursday in the journal Neuron.
Can you imagine the potential?by