SCIENCE IN THE NEWS DAILY
No New Neurons for Smell?
from ScienceNOW Daily News
Do our brains continue to produce neurons throughout our lifetimes? That's been one of the most hotly debated questions in the annals of science. Since the 1950s, studies have hinted at the possibility, but not until the late 1990s did research prove that the birth of new neurons, called neurogenesis, goes on in the brains of adult primates and humans.
Now a surprising new study in humans shows that in the olfactory bulb--the interface between the nose and the brain and an area long known to be a hot spot of neurogenesis--new neurons may be born but not survive. The finding may rule out neurogenesis in this area, or it might show only that some people don't stimulate their brains enough through the sense of smell, some researchers say.
Previous studies have found evidence of neurogenesis in the olfactory bulb of adult humans. But those studies measured only proteins produced by immature neurons, leaving open the question of whether these youngsters ever grew up to connect with other cells to form functional networks, says neuroscientist Jonas Frisén of the Karolinska Institute in Stockholm. If new olfactory neurons really reached adulthood throughout a person's life, researchers should find neurons of a variety of ages in this region.