From time to time, I’ve asked around for a good estimate of how many neurons are in the human brain. Ten billion–100 billion–something like that, is the typical answer I get. But there are actually a trillion other cells in the brain. They’re known as glia, which is Latin for glue–which gives you an idea of how little scientists have thought of them. But without glia, our brains would be useless. Scientists don’t yet really understand all the things that glia do for us, but it looks as if they do a lot–perhaps even processing information in their own mysterious way.
In my brain column in the September issue of Discover, I consider the long-neglected neurological elephant in the corner. Check it out.
[Image from Neurophysiology for the Audiologist]
August 19th, 2009 at 12:06 pm
Remember how all those glia cells in the dolphin brain were supposed to make them dumb? They were “flippin’ idiots” according to one headline. This was the contention in 2006 of Paul Manger, a Southafrican neuroanatomist. His view created quite a stir (see below commentaries) and an official rebuttal by Lori Marino and other scientists in PLOS-Biology.
You argue that the glia cells actually contribute to our brain power. So, same may be true for the dolphins.
http://www.dolphincommunicationproject.org/main/index.php?option=com_content&task=view&id=1117&Itemid=285
http://www.emory.edu/LIVING_LINKS/NYT_oped.html
August 19th, 2009 at 12:26 pm
I’ve read the Discover article and just want to contribute a few thoughts related to personal experience.
I have not been sick often in my life and a state of well being I am sure contributes to freer mental functioning, encouraging exploration and research, rather than status quo. As women age, their doctors recommend that they take calcium to help with thinning bones and to prevent osteoporosis. I have tried several times at their suggestion to take calcium supplements and I am frustrated at my body’s reaction. I can’t stay well with the calcium. In fact, after the initial dose, and ill feeling, I tried a second time with the second attempt not alleviating as quickly, but causing enough distress for long enough that I began to think it might be a flu virus. In attempting to alleviate those symptoms as if they were a second set, I felt as if I developed yet another series of symptoms and think that it may all relate back to the calcium supplements encouraged at my routine doctor’s checkup.
After reading about calcium in the brain, I am increasingly concerned for this reason: As I was attempting to return to wellness, I noticed that my usual mental functioning had become impaired or disintegrated. My entire mental purpose concentrated on getting my body well, which is a whole separate set of “instructions”. I did not enjoy the process and grew to appreciate again my fellows who deal daily with health issues with a new respect.
I cannot help but wonder after reading the article and blog whether my mind had reduced its neuron use and instead fallen back into “care of the body” use of which I am not entirely conscious. Mental instructions to the rest of my body are not ones that I comprehend or typically seek. While autonomic brain “instructions” may work to get me well, they are mostly useless in allowing me to think through problems and appreciate my mental life for what it is.
Thanks for printing this research and good luck.
August 19th, 2009 at 12:49 pm
Brenda, needless to say — stop taking calcium. You have discovered that, unfortunately, there are often consequences to seemingly innocuous acts. Doctors tell any woman past a certain age to take calcium. It’s usually a wasted of time. You need extra calcium in your formative years to lay a solid foundation of bone density. More to the point, weight bearing exercise is magnitudes more effective than calcium at improving bone density. There are darn few cultures in the world that get as much calcium as we do. And yet we have substantially more osteoporosis than, well, pretty much anyone. Everyone should drop the calcium pills and pick up a barbell. Non-excessive but challenging weight training for the major muscle groups would just about erradicate osteo in a generation.
I know, that was kind of off topic. I’m actually a fan of supplementation, believe it or not. But it’s a pet peeve of mine that it’s often done without any understanding of the pros and cons of a given supplement.
August 19th, 2009 at 3:53 pm
Stupendous article. All through it I was thinking how wonderful it is when we discover how little we know and how much is still out there waiting to be learned. Then I came to your final paragraph and found you saying the same. Hurrah for unplumbed wonders!
August 19th, 2009 at 7:35 pm
It’s an old neurologists joke: the brain has about 10^10 neurons, of which 10^11 are purkinje cells in the cerebellum [near the brainstem and handles coordination, among other things].
August 19th, 2009 at 9:26 pm
eyesoars:
I think its “granule cells in the cerebellum” not Purkinje cells. Purkinje cells are large and nowhere as numerous as the tiny granule cells.
August 20th, 2009 at 11:11 am
I believe this is how the whole “we only use 10 percent of our brains” chestnut got started with the glial cells representing the “unused” part of the brain. The fact that everything has a function seemed to be lost on the early science populists.
August 23rd, 2009 at 6:26 pm
[...] 23, 2009 in brains, health Carl Zimmer’s got an interesting new column in Discover about brain cells called glia. Greek for ‘glue’, glia for a long time took [...]