In Depth

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In Depth

Mind-Controlled Robots: Science Fiction or Reality?

By Jenifer Lienau Thompson

At Pitt, it’s a reality! A team of researchers led by UPMC Neuroscientist Andrew Schwartz has been working for years to develop a brain-computer interface, or BCI for short.  They started by figuring out how the neurons in the motor cortex (the part of the brain that controls muscle movement) work, then they invented a way for the brain to communicate with a robot.  It’s been a lot of effort over many years, and now it’s paying off.

Dr. Schwartz and his team spent about 10 years working with monkeys, figuring out which neurons controlled which actions and training the monkeys to control robotic arms with their intentions. This part really does seem like something out of science fiction: The brain directs the robot through two electrode chips that have been surgically implanted in the motor cortex. Each chip has 96 tiny pins that sense electrical signals from nerve cells in the brain. The chips are attached by wires to a “connector” that looks like a little black jewelry box on top of the skull, and a wire from the connector plugs into the robotic arm.

To find out if their invention worked with humans, the team had to find someone willing to undergo brain surgery, receive chip implants, and literally plug into a robot. Brain surgery may not be high on your list of fun things to do, but for people who have lost the use of their arms, this project is the chance of a lifetime.

Jan Scheuermann is 53 years old and has two kids. She is also a quadriplegic -- she has lost the use of her arms, legs, and torso to a degenerative (worsening) nerve disease. She has not been able to move her arms or legs for over 10 years. When she found out about Dr. Schwartz’s BCI project she volunteered right away.

To be part of the project Jan had to “try out”. Doctors tested her to make sure she was a good fit for the robotic arm and that she was healthy and strong enough to undergo brain surgery. Once the doctors decided Jan was a good candidate, researchers made a map of her brain so they could figure out exactly where to put the two microchips. They needed to place the chips near neurons that fired when Jan thought about moving her right arm up, down, right, left, and about grasping something or twisting her wrist. Then Pitt Neurosurgeon Elizabeth Tyler-Kabara implanted two quarter-inch square electrode grids into Jan’s brain, placing them in the region that corresponded with movement of her right arm, about one-sixteenth of an inch deep into the brain tissue. Just like in the monkeys, the contact points sense electrical signals from neurons in Jan’s motor cortex and transmit them to the connector mounted on her skull. When the connector is plugged into the robot arm, the circuit is complete.  A computer interprets the signals from Jan’s brain and tells the robot what to do.

The researches assumed that it would take some time for Jan to learn to direct the robot with her brain, so they were surprised when she was able to achieve 3-dimensional control and even give them robotic high-fives within a week of her surgery. By the end of three months, she could flex the robot’s wrist, move it side to side and even grasp and move objects from one place to another.

Jan’s success is very exciting for her, and for the team of researchers who have worked on making the stuff of science fiction into reality. But this project reaches much further – it gives hope to many people who have lost their independence to paralysis or amputation. As Jan said after she was able to feed herself chocolate for the first time in over 10 years, “one small nibble for a woman, and one giant bite for BCI.”

What’s next for Dr. Schwartz and his team? It looks like they want to turn more science fiction into reality. For starters they’d like to make the connection between brain and robot wireless so that the patient won’t be tied to a cord. Also, they hope to program the robot to feed sensory information back to the brain so that patients can adjust movement to fit tasks, such as combing their hair or hammering a nail. Dr. Schwartz thinks that in five or 10 years, patients might be using these machines in daily life, realizing their human potential cyborg style. 

 

Mitochondria - Even Mightier Than We Thought

By Jenifer Lienau Thompson

You may think that you are just sitting there reading, but right now your body is working pretty hard. Your heart pumps blood throughout your body, your diaphragm pulls air into your lungs, muscles in your back and abdomen hold your body up. Within your organs and tissues, cells cooperate to perform all these activities. Muscle cells expand and contract so your eyes can scan the screen, nerve cells transmit messages about these words to your brain, and brain cells works together to decipher their meanings. It actually takes a lot of energy to sit there and read - imagine how much it takes to ride a bike, turn a cartwheel or run a marathon!

Where do you get all the energy you need? Just as your mom has always told you, it begins with the food you eat. But a peanut butter and jelly sandwich (PB&J) is not exactly cell food - at least not yet. Your digestive system breaks the PB&J down into its molecular ingredients: proteins, sugars, and fats - and your blood vessels deliver them to cells throughout your body. Tiny power plants that look like little loaves of bread inside your cells, called mitochondria, combine the food molecules with oxygen to make ATP - an energy-storage molecule that acts like a rechargeable battery, providing energy for everything you do.

Two recent articles by Joe Miksch in PittMed magazine examine new developments in our understanding of mitochondria's mighty influence on human health. For a long time, scientists thought that mitochondria's sole purpose was to generate energy, but we now know that they do a lot more. Throughout your life, mitochondra (researchers sometimes call them "mitos" for short) copy the cellular energy production system perfectly, millions of times over. They also convince sick or damaged cells to die quickly and quietly. Pitt researchers think that these less-appreciated mitochondrial roles may unlock the mysteries of some devastating diseases like cancer and Parkinson's.

The problem seems to be rooted in how mitochondria replicate and produce energy. They actually have their own special DNA - a very short strand of it - which they continuously copy. Mitochondrial DNA (mtDNA) encodes the instructions on how to make proteins that convert food and oxygen into energu.

Imagine that you had to copy the same sentence over and over and over again, millions of times. You might make a spelling or grammar mistake once in a while. If you weren't paying attention, you might repeat the mistake. Eventually, the mistake could become a permanent part of your sentence. Sometimes mitochondria make mistakes, called mutations, when they copy their DNA. Mitos constantly fuse together and divide, fixing mistakes and throwing out faulty DNA that can't be repaired. But occasionally, mutations go undetected and get copied. When this happens in mitochondrial DNA (mtDNA), things can go very wrong.

Take cancer, for instance. Pitt's own Bennett Van Houten has studded mitochondria for decades. He and his partners think they may have unraveled one of cancer's more perplexing mysteries based on mitochondria's ability to make ATP (remember, ATP is like a battery for your cells). When mutations in mtDNA cause ATP production to go wild, cancer cells have access to an unlimited source of energy that they can use to grow and reproduce. Van Houten thinks that treatment targeting mitos could stop cancer in its tracks. But drugs that impact mitochondria in cancer cells will also hurt them in healthy cells. So the idea is to attack the cancer from two directions; target mitochondria with one medicine and use an effective chemotherapy drug to kill cancer cells. Initial testing in the lab looks promising, but it will be a while before scientists have this approach ready to use in patients.

Mitochondrial DNA may also be the key to new treatments for some neurological diseases. An exciting new development in Parkinson's disease research has shown that a certain mtDNA mutation creates a toxin that kills specific neurons in the brain - the ones that control voluntary movement. Over time, a Parkinson's patient can suffer from trembling, painfully stiff muscles, and can even lose muscular control. Sarah Berman, Pitt assistant professor of neurology, studies how mitochondria replicate in nerve cells. She noticed that if mitochondria don't fuse and divide properly in nerve cells, the cells die. She thinks that if we can find a way to ensure proper fusion and division, we might be able to stop Parkinson's before it starts. Turning that idea into reality is a long way off, but it shines a ray of hope into what has always been a dark diagnosis.

For more information on Parkinson's disease, please visit The Society for Neuroscience or the National Parkinson's Foundation. If you would like to know about the latests developments in cancer research and treatments try the American Cancer Society.