Saturday, August 19, 2006

Your thalamus is a club bouncer

Having a little trouble waking up this morning? Perhaps your brain stem isn't transmitting enough nitric oxide to your thalamus ...

As we yawn and open our eyes in the morning, the brain stem sends little puffs of nitric oxide to another part of the brain, the thalamus, which then directs it elsewhere.

Like a computer booting up its operating system before running more complicated programs, the nitric oxide triggers certain functions that set the stage for more complex brain functions, according to a new study.

Let me pause the article for a moment and say that I am one of those weirdos who has always been able to wake up early in the morning, and wake up wide awake. I inherited this from both parents; my mother would pop out of bed at 5 a.m. intense and focused; my father was at the refinery before 7 a.m. throughout his working career. I have become even more pronounced in this pattern as I've gotten older (witness many of my postings here as evidence). Furthermore, it took me a long time to understand that I am the exception compared to most other people. I spent quite a few years being harsh on those with whom I shared living arrangements -- siblings, roommates, spouse -- who could sleep soundly until noon. (Frankly, most of my life I thought they were simply lazy.)

In these first moments of the day, sensory information floods the system—the bright sunlight coming through the curtains, the time on the screeching alarm clock—and all of it needs to be processed and organized, so the brain can understand its surroundings and begin to perform more complex tasks.

"The thinking part of the brain is applying a sort of stencil to the information coming in and what the nitric oxide is doing is allowing more refinement of that stencil," says Dwayne Godwin, an associate professor at Wake Forest University and lead author of the study, which was funded by the National Eye Institute.

The little two-atom molecule, it seems, is partly responsible for our ability to perceive whatever it is we're sensing.


The thalamus was thought to be a fairly primitive structure, sort of a gate that could either open and allow sensory information to stream into the cortex, the higher functioning part of the brain, or cut off the flow entirely.

Godwin says the new research shows it's more accurate to think of the thalamus not as a gate but as a club bouncer, who doesn't simply allow a huge rush of people to go in or no one at all, but picks and chooses whom to let in and out.

"Instead of vision being a process going straight from eye to cortex, it's more of a loop," Godwin explained. "This constitutes a new role for the thalamus in directing, not just modulating."

While this study is the first to identify nitric oxide's role in the thalamus, elsewhere in the body it was already known to have an important, if somewhat different function. The molecule is actually integral to controlling blood flow and is, in fact, the molecule Viagra targets in order to increase blood flow to the penis.

The teeny molecule might have other medical uses.

"This study shows a unique role for nitric oxide. It may help us to someday understand what goes wrong in diseases that affect cognitive processing, such as attention deficit disorder or schizophrenia, and it adds to our fundamental understanding of how we perceive the world around us," Godwin said.

The club bouncer uses Viagra. Well, he's so obese that I guess he has to. What a simultaneously compelling and repulsive visual (within my own personal subcortex, of course).

There might be more postings today live from Camp Wellstone, as I can find a few moments. There are about sixty or so of us in attendance, most from Houston and elsewhere in Texas but also an independent candidate from Oklahoma, a guy whose family owns a restaurant in Chicago and a New York author of erotica.

No comments: