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June 21, 2006
| Neurons Regenerate After All | Science/Technology |
This is a surprise. For as long as I can remember, I've read that adult humans don't grow new brain cells. Whatever we've got, going into adulthood, we're stuck with. Apparently, not so. It depends on your environment. Barbara Ehrenreich, in the current issue of The Progressive:
[A] recent article in the new pop-science magazine, Seed, makes me think that our office environments [cubicles and windowless offices] may be more damaging than I suspected. The article is about neurogenesis, the generation of new neurons within adult brains. According to longstanding neuroscientific belief, this is impossible: Neurons cannot regenerate, and we are stuck with the number we were born with, minus those lost to alcohol or Alzheimer's. Princeton psychologist Elizabeth Gould has shown otherwise: Neurons can regenerate. The reason this hadn't been observed before is that the animals studied lived out their short lives in plain laboratory metal cages.Gould studies little rat-sized monkeys called marmosets. Put them in metal cages, kill them, and slice their brains for microscopy, and you find very little neurogenesis. But if you let them live in an "enriched enclosure" — the marmoset equivalent of Versailles, featuring "branches, hidden food, and a rotation of toys" — neurogenesis kicks in, along with an increase in the number and strength of synaptic connections.
Another scientist, Fernando Nottebohm, working at my alma mater, Rockefeller University, has found a similar effect in birds. Keep finches and canaries in metal cages and you get listless, tuneless, birds with equally dull brain tissue. Only when studied in the wild do the birds sing and, not coincidentally, generate a profusion of new brain cells. [Emphasis added]
Neurons being regenerated. That's a pretty fundamental thing to have been missed for all these years.
Here's something to consider. Much of our understanding of biology and medicine comes from experiments involving animals held in the bleakest conditions of unhappy captivity. You have to wonder the extent to which that's skewed our understanding across the board. It's like trying to arrive at a balanced understanding of human organisms by studying only the inmates of Auschwitz. It's a measure of the erosion of our basic common sense that any of this comes as a surprise.
Posted by Jonathan at June 21, 2006 11:21 PM
