How many nerve cells does a bird have? While researching this, I was reminded of this research that shows adult birds, like adult humans can grow new nerve cells.
… Deconstructing birdsong may seem an unlikely way to shake up biology. But Nottebohm’s research has shattered the belief that a brain gets its quota of nerve cells shortly after birth and stands by helplessly as one by one they die–a “fact” drummed into every schoolkid’s skull. On the contrary, the often-rumpled Argentina-born biologist demonstrated two decades ago that the brain of a male songbird grows fresh nerve cells in the fall to replace those that die off in summer.
The findings were shocking, and scientists voiced skepticism that the adult human brain had the same knack for regeneration. “Read my lips: no new neurons,” quipped Pasko Rakic, a Yale University neuroscientist doubtful that a person, like a bird, could grow new neurons just to learn a song.
Yet, inspired by Nottebohm’s work, researchers went on to find that other adult animals–including human beings–are indeed capable of producing new brain cells. And in February, scientists reported for the first time that brand-new nerves in adult mouse brains appeared to conduct impulses–a finding that addressed lingering concerns that newly formed adult neurons might not function. Though such evidence is preliminary, scientists believe that this growing body of research will yield insights into how people learn and remember. Also, studying neurogenesis, or nerve growth, may lead them to better understand, and perhaps treat, devastating diseases such as Parkinson’s and Alzheimer’s, caused by wasted nerves in the brain.
Few would have predicted that canary courtship would lead to such a breakthrough. Nottebohm’s bird studies “opened our eyes that the adult brain does change and develops new cells throughout life,” says neurobiologist Fred Gage of the Salk Institute in La Jolla, California, whose lab recently found evidence of nerve cell regrowth in the human brain.
Nottebohm’s research has achieved renown in biology and beyond. A scientist who advances an unconventional view and is later vindicated makes for compelling drama, presenting a hero who appeals to the rebel in us and a cautionary lesson to stay open-minded. Yet Nottebohm prefers being a revolutionary to a statesman. “Once I was in the 5 or 10 percent of scientists who believed in neurogenesis,” he says. “Now 95 percent accept that position. I rather liked it better being in the minority.”…