It is well known how we humans respond to immediate stress—through a phenomenon we share with all animals known as fight or flight. During these times of increased threat, our bodies’ systems work in concert to raise our heart rate, pump adrenaline, and sharpen our focus. Now scientists working at Northwestern University have discovered that these responses may be coordinated by special stress-receptor neurons, rather than in each cell individually. Previously, cells were assumed to each respond to stress conditions (such as an increase in temperature) on their own. But as research on the tiny C. elegans worm shows this month in the journal Science, neurons are responsible for coordinating the animal’s cells and their reply.
The C. elegans worm is a favorite of cellular researchers, paradoxically, because it is at once simple and complex. It has a functioning nervous system, but the worm itself is made up of less than 1000 cells, the lineage of which has been mapped for each one. That means researchers know what to expect out of just about every individual part of the animal down to the cellular level. So when they discovered that just two neurons were responsible for the other 957 cells’ behavior in stress situations, they were quite surprised. By genetically shutting down the heat-sensing ability of those neurons, they found that no other cell subsequently responded to temperature stresses.
In more complicated organisms then, neurons may be responsible for coordinating local networks of cells to respond to stress, which if true, could help us better understand diseases which affect those pathways.