Neuroprosthetics and deep brain stimulation: Two big neuroscience breakthroughs
Neuroscience is working to conquer some of the human body's cruelest conditions: Paralysis, brain disease, and schizophrenia.
SUSAN HOCKFIELD: One issue that I think haunts all of us is enabling the disabled. How can we make it possible for people who have lost the ability to use their limbs -- either by amputation or by stroke -- how do we give them a better life? How do we make their lives more enjoyable, give them greater mobility? One of my colleagues -- going back to my early days as a neuroscientist -- John Donoghue, has been fascinated in how the part of our brain that controls movements works. It's called the motor cortex, part of the cerebral cortex; it's located just about here. And we have known for many, many, many years that signals from the nerve cells in that part of the brain drive motions. If I want to reach out my arm to grab a glass of water, it's signals from the motor cortex that send their information down the spinal cord in our back and then out to the limbs. If you've had a spinal cord injury or a stroke, those connections are interrupted. But John Donoghue understood that just because the connections were interrupted didn't mean that the motor cortex wasn't working. And he resolved to figure out a way to pick up the signals from the motor cortex and translate them into either a robotic arm or an individual's own arm by connecting to another set of electronics that could drive the muscles in the arm of someone who was paralyzed.
He and his colleagues have invented an intracortical brain computer interface; it's a very, very teeny set of electrodes -- it's about the size of a baby aspirin -- that has a hundred very fine wires that can sit in the motor cortex. They pick up the signals from the nerve cells in the motor cortex and relay them to a computer. The computer then decodes the signal and then can send that signal out to a robotic arm or, as I said, through a number of connections back to the individual's own arm and gives that individual the ability, for the first time since their injury, to feed themselves, to grab a cup of coffee and take a sip by themselves. So it gives them a kind of independence they never had.
One of John Donoghue's colleagues, Dr. Leigh Hochberg, who's worked closely with him on these experiments, told me something really quite extraordinary. The whole world of deep brain stimulation, which is related, and it's a world that is related to recording signals from the brain, but also driving brain activity by stimulating electrodes in the brain. And this kind of deep brain stimulation has proved effective for some kinds of epilepsy. It's proved remarkably effective for some individuals with Parkinson's, it has controlled their tremors. And there are a lot of possibilities. The problem with understanding the brain and intervening is there are a billion nerve cells in the brain, and figuring out how each one participates in an activity is a daunting task, to put it mildly. But what these experiments suggest is that we may not need to do a cell by cell analysis. We may not need a cell by cell understanding of the circuitry that drives a particular activity, an activity we want or an activity we don't want. We may be able to operate at the level of ensembles of neurons, and this is what happens when we use deep brain stimulation to control epilepsy or control Parkinson's.
What Dr. Hochberg told me about was his dream, and it is really a quite inspiring dream. Besides epilepsy, there are other diseases that are intermittent. And he suggests that perhaps for something as complicated as schizophrenia, where some of the time an individual who has schizophrenia will be functioning absolutely normally, and then the brain departs from a normal function into an aberrant function, which is manifest in all of the signs and signals of schizophrenia. What he suggests is that we may someday -- and let's hope in the not so distant future -- be able to record from an individual's brain and understand when the signals began to move into the schizophrenic mode and perhaps be able to stimulate the brain to correct that back to the normal mode.
- Neuroscience and engineering are uniting in mind-blowing ways that will drastically improve the quality of life for people with conditions like epilepsy, paralysis or schizophrenia.
- Researchers have developed a brain-computer interface the size of a baby aspirin that can restore mobility to people with paralysis or amputated limbs. It rewires neural messages from the brain's motor cortex to a robotic arm, or reroutes it to the person's own muscles.
- Deep brain stimulation is another wonder of neuroscience that can effectively manage brain conditions like epilepsy, Parkinson's, and may one day mitigate schizophrenia so people can live normal, independent lives.
Can dirt help us fight off stress? Groundbreaking new research shows how.
- New research identifies a bacterium that helps block anxiety.
- Scientists say this can lead to drugs for first responders and soldiers, preventing PTSD and other mental issues.
- The finding builds on the hygiene hypothesis, first proposed in 1989.
Are modern societies trying too hard to be clean, at the detriment to public health? Scientists discovered that a microorganism living in dirt can actually be good for us, potentially helping the body to fight off stress. Harnessing its powers can lead to a "stress vaccine".
Researchers at the University of Colorado Boulder found that the fatty 10(Z)-hexadecenoic acid from the soil-residing bacterium Mycobacterium vaccae aids immune cells in blocking pathways that increase inflammation and the ability to combat stress.
The study's senior author and Integrative Physiology Professor Christopher Lowry described this fat as "one of the main ingredients" in the "special sauce" that causes the beneficial effects of the bacterium.
The finding goes hand in hand with the "hygiene hypothesis," initially proposed in 1989 by the British scientist David Strachan. He maintained that our generally sterile modern world prevents children from being exposed to certain microorganisms, resulting in compromised immune systems and greater incidences of asthma and allergies.
Contemporary research fine-tuned the hypothesis, finding that not interacting with so-called "old friends" or helpful microbes in the soil and the environment, rather than the ones that cause illnesses, is what's detrimental. In particular, our mental health could be at stake.
"The idea is that as humans have moved away from farms and an agricultural or hunter-gatherer existence into cities, we have lost contact with organisms that served to regulate our immune system and suppress inappropriate inflammation," explained Lowry. "That has put us at higher risk for inflammatory disease and stress-related psychiatric disorders."
University of Colorado Boulder
This is not the first study on the subject from Lowry, who published previous work showing the connection between being exposed to healthy bacteria and mental health. He found that being raised with animals and dust in a rural environment helps children develop more stress-proof immune systems. Such kids were also likely to be less at risk for mental illnesses than people living in the city without pets.
Lowry's other work also pointed out that the soil-based bacterium Mycobacterium vaccae acts like an antidepressant when injected into rodents. It alters their behavior and has lasting anti-inflammatory effects on the brain, according to the press release from the University of Colorado Boulder. Prolonged inflammation can lead to such stress-related disorders as PTSD.
The new study from Lowry and his team identified why that worked by pinpointing the specific fatty acid responsible. They showed that when the 10(Z)-hexadecenoic acid gets into cells, it works like a lock, attaching itself to the peroxisome proliferator-activated receptor (PPAR). This allows it to block a number of key pathways responsible for inflammation. Pre-treating the cells with the acid (or lipid) made them withstand inflammation better.
Lowry thinks this understanding can lead to creating a "stress vaccine" that can be given to people in high-stress jobs, like first responders or soldiers. The vaccine can prevent the psychological effects of stress.
What's more, this friendly bacterium is not the only potentially helpful organism we can find in soil.
"This is just one strain of one species of one type of bacterium that is found in the soil but there are millions of other strains in soils," said Lowry. "We are just beginning to see the tip of the iceberg in terms of identifying the mechanisms through which they have evolved to keep us healthy. It should inspire awe in all of us."
Check out the study published in the journal Psychopharmacology.
We were gaining three IQ points per decade for many, many years. Now, that's going backward. Could this explain some of our choices lately?
There's a new study out of Norway that indicates our—well, technically, their—IQs are shrinking, to the tune of about seven IQ points per generation.
An ordained Lama in a Tibetan Buddhist lineage, Lama Rod grew up a queer, black male within the black Christian church in the American south. Navigating all of these intersecting, evolving identities has led him to a life's work based on compassion for self and others.
- "What I'm interested in is deep, systematic change. What I understand now is that real change doesn't happen until change on the inside begins to happen."
- "Masculinity is not inherently toxic. Patriarchy is toxic. We have to let that energy go so we can stop forcing other people to do emotional labor for us."
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