Motor Neurons May Have Unique Stress Response

Motor neurons, the nerve cells that die in amyotrophic lateral sclerosis (ALS), as well as other neurons, seem to have a particularly high threshold for activating a stress response that non-neuronal cells activate more easily, according to findings from the laboratory of MDA grantee Heather Durham at Montreal Neurological Institute at McGill University. That problem, if it could be remedied, might become a therapeutic avenue in ALS, the researchers say.

Building on work in the Durham lab and by Ian Brown at the University of Toronto at Scarborough, graduate student David Taylor and colleagues set out to decipher why the usual pathways for turning on protective stress responses are difficult to activate in motor neurons, whether or not they’re affected by ALS.

They found that neuronal cells don’t start production of protective compounds called heat shock proteins in response to the usual signals that activate these proteins in other cells.

The team, which published its findings in the January issue of Molecular and Cellular Neuroscience, identified a new pathway for turning on heat shock protein production in neurons, one that didn’t trigger this response in non-neuronal cells.

“These are clues pointing to alternative mechanisms of activating stress responses in neurons compared to other cells, and we’re continuing to try to identify these pathways,” Durham said.