A Scientist’s Pink Cast Leads to Discovery of Brain Pulses That Keep Disused Circuits “Alive”

    By Kathleen Berger, Executive Producer for Science & Technology

    For Nico Dosenbach, MD, PhD there’s nothing unusual about conducting research using his own body. The neuroscientist would lie for hours in a MRI scanner after midnight for scans of his brain.

    After midnight is considerably less expensive, as scanning charges with the MRI are 90% off. Dosenbach explained it’s the best way to uncover the mysteries of the human brain. But for this to happen, the assistant professor of neurology at Washington University School of Medicine in St. Louis wanted more ‘brains’ for his research, which meant getting creative for recruitment, by having fun with it!

    “Scientists aren’t thought of as being cool,” said Dosenbach. “So we tried our own nerdy version of a club or a gang.”

    The “Sons of Anarchy” TV drama about a fictitious motorcycle club gave Dosenbach the idea to form a club for his gang of enterprising scientists, called Midnight Scan Club. Instead of a skull on leather for a logo, he has a brain in the shape of a skull on a club t-shirt with the latin phrase “carpe noctem”, which means to seize the night.

    After midnight, they took turns in the MRI scanner generating a massive amount of high-quality data, making discoveries and publishing papers.  Spending hours in the MRI scanner is at least worth the club t-shirt! But being in the scanner while having an arm in a cast? Dosenbach had a brain scanning experiment that involved casting his right arm in order to immobilize his primary arm, wrist and hand. It wasn’t just any full arm cast. It had a vibrant neon color of hot pink!

    “You get quite the reaction,” he said. “‘What happened? Did you break your arm?’ And you say ‘No, actually it’s for research’ and they really want to know what kind of crazy you are.”

    Not crazy at all! Not with what he would discover by scanning his brain every day for six weeks: two weeks before, two weeks during and for two weeks after the cast was removed. Dosenbach wanted to know about the plasticity of the adult brain, to see how plastic it may be, meaning its ability to adapt and rewire itself responding to functional changes.

    “What the cast did was reduce use of the previously dominant arm by as much as having a stroke would have.”

    So he decided to be put into the neon pink cast for two weeks. Now that the “Pink Cast Study” is published, the Midnight Scan Club has a new look! And it’s not just hot pink. Dosenbach chose the eye-catching color as a form of marketing for recruitment of more arms in casts with new colors and data from brain scans.

    “Lots of people asked me what had happened and so I would just go around telling the story and sure enough people started lining up saying ‘hey I want to do it.’”

    The pink cast was followed by a neon yellow cast and another member’s neon green cast. The data showed how the adult brain is more plastic than expected. They discovered how quickly the brain adapted to the immobilized limb. In the brain scans, they found previously undetected brain pulses that activate quickly, within two days.

    “Huge spikes of spontaneous activity, sharp looking that normally aren’t ever there that were very much specific to the parts of the brain that had been disused,” said Dosenbach. “That’s kind of shocking because you can see them with the naked eye. All you have to do is plot out the data.”

    Dosenbach said they are disuse pulses, or spontaneous bursts of neurons firing. The research team discovered that during the two weeks the casts were worn, participants’ brains produced the spontaneous pulses that seemed to maintain neural activity in the disused circuits.

    “One thought is that these are actually protective pulses in the sense that the brain partially, at least, expects the arm to come back into action.”

    Dosenbach said this allowed the main motor circuits to reactivate after the casts came off. The neurons quickly began firing again when mobility was regained.

    “Within two days it felt like everything was back to normal and the brain data showed the same thing,” said Dosenbach. “So instead of letting the circuitry for your upper extremity dissolve, it actually starts making its own activity to keep the circuit protected and alive. It’s almost like you put it in storage because you’re going to bring it back. To me, that might be a potential explanation why the functional architecture of the brain recovered so quickly.”

    There was a significant effect from immobilizing the arm, wrist and hand for two weeks.

    “I think I lost 30 pounds of grip (hand) strength. The grip strength came back all the way to baseline in everybody in two weeks or less.”

    The findings can lead to advances in treatment for people recovering from strokes, broken limbs or other immobilizing conditions.

    Dosenbach wants to know how long the disuse pulses may last for the brain to overcome disuse. With many more questions now begging for answers, he said he will need to have another ‘casting call’, in a different sense of the term, to cast more members of the club.

    “Science doesn’t get enough credit for being a fairly creative enterprise,” he said. “I think the part that people didn’t really believe was going to happen – was actually doing it.  But we did. And it was very well worth it.”