Science Daily — Hopkins researchers have identified a backup supply of stem cells that can repair the most severe damage to the nerves responsible for our sense of smell. These reservists normally lie around and do nothing, but when neighboring cells die, the scientists say, the stem cells jump into action.

Isn’t that fantastic? God is such an amazing architecht!

“These stem cells act like the Army Reserves of our nose,” explains lead author Randall Reed, Ph.D., a professor of neuroscience at Johns Hopkins, “supporting a class of active-duty stem cells that help repair normal wear and tear. They don’t come in until things are really bad.”

To figure out how the olfactory system repairs severely damaged nerve cells, Reed’s team exposed mouse olfactory nerves to a cloud of toxic methyl-bromide gas. Methyl bromide kills not only olfactory nerve cells but also neighboring, non-nerve cells in the nasal passage. Three weeks after chemical exposure, the researchers examined nasal cells to see which, if any, had grown back.

They discovered that the newly grown cells, both nerve and non-nerve, grew from HBCs-a population of cells not previously known for repair abilities. “We were stunned because HBCs normally don’t grow much or do anything,” says Reed. “And the most surprising thing is that HBCs can grow into both nerves and non-nerve cells; they do so by generating the other active type of nasal stem cell.”

Interestingly, it was stem cells taken from olfactory tissue that helped repair damaged spinal cords in Dr. Lima’s clinical study.