The team studied mice with a mutation in a gene for superoxide dismutase 1 (SOD-1), which in healthy people and mice plays an important role keeping cells safe from damaging molecules known as free radicals. Scientists estimate that SOD-1 mutations play a role in a small number of cases of ALS overall in people, about one-quarter of the 10 percent or so of cases that are inherited. But those cases provide a unique window to study the diseases initial steps.
In the Nature Neuroscience paper, the group from Rochesters Center for Neurodegenerative and Vascular Brain Disorders and UCSD showed that a breakdown in the natural barrier between the blood and the spinal cord breaks down early on in mice destined to get ALS, long before nerve cells appear sick or die.
In this work, the team showed that the barrier between the blood and the spinal cord weakens in all three types of genetically based ALS cases that involve SOD-1 mutations, allowing toxic substances to flood into the spinal cord and directly affect neurons.
That barrier is crucial for the health of our central nervous system, which is treated like the inner sanctum of the body. Like a high-performance race car that demands a choice fuel, our neurons work well only if the chemical environment in the brain and spinal cord is precisely maintained within a strict, narrow set of conditions.
To maintain that select environment, the body has strict barriers or gateways for substances entering or exiting the central nervous system. Blood vessels run through our brain and spinal cord and supply oxygen and other nutrients, and the lining of those blood vessels constitutes a biochemical barrier to protect the central nervous system from toxins, inflammatory cells, red blood cells, blood products, and a variety of other potential toxic insults.
The barrier between the blood and the spinal cord isnt some stand-alone structure that keeps all substances away from the spinal cord.
|Contact: Tom Rickey|
University of Rochester Medical Center