Thursday, July 28, 2016
Fix My Brain
Red wire: Right temple
Black wire: Left temple
As I think any lay audience is aware, we conventionally take in all our information about the world through our five senses. External receptors that sense light, touch, sound, taste and smell send messages about these stimuli into our brains, where they are processed and interpreted. However many techniques available to neuroscientists can bypass the sensory pathways and directly stimulate the brain.
In 2008, a team of neuroscientists from Cold Spring Harbor Laboratory led by Karel Svoboda published the results of a simple yet remarkable experiment. Svoboda's group took advantage of a new technology now in wide use called optogenetics that allows the experimenter to activate a defined set of neurons by simply illuminating them with blue light. They were interested in what would happen if they did this in an awake behaving mouse. Could the mouse detect the activation? Could it learn to reliably make a behavioral response when it was detected?
This was hardly the first time neuroscientists directly stimulated deep brain neurons, so the fact that the answer was yes was not so surprising. However, this was the first time the experimenters could know precisely how many neurons they were activating and for how long. So the real question was what is the minimum number of neurons they would need to activate for the mouse to reliably perceive the stimulation? The answer was surprisingly few. Despite the fact that there roughly 70,000,000 neurons in the mouse brain, instantaneous activation of merely 300 was sufficient for the mouse to reliably respond.
I remember reading this paper is a postdoc and wondering what that would feel like.
They put a hot wire to my head
For the things I did and said
I have been fortunate to have had the opportunity to participate in a number of research studies of P. Many parkys do this for all kinds of reasons. A common one is obviously the hope that one might discover a new treatment that brings them some benefit. I am no exception in that regard, but being a neuroscientist myself, I can't resist getting in on doing some science where I am the subject for once. I told some people that I was having an experimental therapy and they looked worried if it was some desperation Hail Mary pass. On the contrary, I'm essentially pretty stable symptom wise, and this was an exciting opportunity.
Two of these studies, including one that I just completed involved use of a method called transcranial magnetic stimulation or TMS. TMS is a totally noninvasive way for my doctors to do something akin to the Svoboda experiment. They more or less jack in and directly activate my brain.
Why did they do this? I don't want to get into the details, largely in deference to the research team because the project is ongoing. The details aren't important anyway. In general terms, they used repeated sessions of rhythmic stimulation of certain regions of my cerebral cortex to hopefully trigger 'neural plasticity,' which means adaptive changes in brain wiring.
Did it work? I think so. The benefit was actually very noticeable in response to the protocol I underwent last year. I started noticing that particularly the night after I had a session, I was shredding on Guitar Hero with my kids. No joke!
How did it feel? That's harder to put into words, but it was certainly fascinating and super weird. It certainly didn't hurt but it can sometimes be annoying, particularly at high intensity. Sometimes it felt like there was a flash, as if someone hit a reset button on my brain. Sometimes, often in fact in the places they were stimulating, it would trigger an involuntary movement. In fact they use this to map the location they stimulate and as a quantitative measure of its effects. Honestly, I wish I could get into that lab with one of my neuroscientist friends and try zapping away at different parts of our brains just to see what happens.
Like Karel Svoboda.