Parkinson’s Disease Symptoms Seen Years Before Diagnosis

Data from a new U.K. study with the most diverse group of patients ever reported show that Parkinson’s disease symptoms — including tremors, cognitive difficulties, epilepsy, and hearing loss — can emerge up to 10 years before a diagnosis. Moreover, ethnicity or socioeconomic status were not found to be associated with Parkinson’s risk.

This study confirms that many of the symptoms and early features of Parkinson’s can occur long before a diagnosis,” Alastair Noyce, PhD, the study’s lead investigator and a researcher at Queen Mary University of London, said in a university press release.

We’re hoping to identify people at high risk of Parkinson’s even before obvious symptoms appear — which means that we could do more than just improve quality of life for patients, and perhaps be in the position to slow down or cure Parkinson’s in the future,” Noyce said.

Importantly, this study also identified hearing loss and seizures as early symptoms of Parkinson’s disease.

The study, “Assessment of Risk Factors and Early Presentations of Parkinson Disease in Primary Care in a Diverse UK Population,” was published in JAMA Neurology.

Source: https://www.qmul.ac.uk/

How to Control Neurons in the Brain

Researchers out of San Diego’s Salk Institute have gotten mice to move their limbs by stimulating brain cells using ultrasound. When mice were engineered to have their brain cells produce a special protein, the researchers found that hitting them with ultrasoundturned on” the cells, causing small, but perceptible, movements in their limbs. The technique, called “sonogenetics,” is the latest in a line of methods that look to stimulate and alter neurons directly, without using drugs.

We’ve spent so much time over the last few decades focusing on pharmacologic therapies,” said Colleen Hanlon, a biologist at Wake Forest not involved with the study. “This paper is another really important piece to this puzzle of developing neural circuit-based therapeutics for disease.”

 Sonogenetics is just one of the ways researchers have begun controlling neurons in the brain, turning them off or on at will. Perhaps the most well-known method is using electrical stimulation. In deep brain stimulation, researchers surgically implant electrodes into specific areas of the brain. When these electrodes fire off at the right time and with the right frequency, they can make tremors disappear, improve memory, and even treat depression.

Taking a step up on the wildness scale, scientists can also activate, or turn off, neurons using light, a technique called optogenetics. Optogenetics works by genetically engineering brain cells to produce light-sensitive proteins, which can be hit with a laser, causing the neuron to fire or not. A similar mechanism is behind sonogenetics, except the protein reacts to ultrasound. Ultrasound is appealing because of its well-understood safety profile and the fact that it is already used to target locations deep within the body. “Ultrasound is safe, noninvasive, and can be easily focused through thin bone and tissue to volumes of a few cubic millimeters,” the researchers wrote in their study, published in Nature Communications.

In optogenetics, by contrast, because skin and bone are opaque, even powerful lights will have a hard time reaching neurons deeper than the outer layer of the brain. Salk neuroscientist Sreekanth Chalasani and his colleagues pioneered sonogenetics several years ago in a tiny worm called a nematode. In the worms, they used an ultrasound-reacting protein called TRP-4. But when they put it into mammalian cells, well … nada. And thus began a six-year quest to find an ultrasound-reactive protein that works in mammals. They found it — a protein called TRPA1. The researchers first tested the protein in mouse neurons in the lab. When those cells reacted to ultrasound by producing electrical signals, they engineered it into living mice. When the TRPA1-producing mice were exposed to ultrasound, electrical signals coursed through their limbs — and a little bit of movement, too.

It’s a very exciting contribution and an important step,” adds Caltech sonogenetics researcher Mikhail Shapiro, who was uninvolved with the work.  “This is one of the papers that’s come out over the last several years that shows that it’s a real possibility that you can use ultrasound to directly modulate the activity of specific neurons.”

Source: https://www.freethink.com/

How to Reverse Parkinson’s Symptoms

Grafting neurons grown from monkeys’ own cells into their brains relieved the debilitating movement and depression symptoms associated with Parkinson’s disease, researchers at the University of Wisconsin–Madison (UW) reported today.

In a study published in the journal Nature Medicine, the UW team describes its success with neurons made from induced pluripotent stem cells from the monkeys’ own bodies. This approach avoided complications with the primates’ immune systems and takes an important step toward a treatment for millions of human Parkinson’s patients.

This result in primates is extremely powerful, particularly for translating our discoveries to the clinic,” says UW–Madison neuroscientist Su-Chun Zhang, whose lab grew the brain cells.

Parkinson’s disease damages neurons in the brain that produce dopamine, a brain chemical that transmits signals between nerve cells. The disrupted signals make it progressively harder to coordinate muscles for even simple movements and cause rigidity, slowness and tremors that are the disease’s hallmark symptoms. Patients — especially those in earlier stages of Parkinson’s — are typically treated with drugs like L-DOPA to increase dopamine production.

Those drugs work well for many patients, but the effect doesn’t last,” says Marina Emborg, a Parkinson’s researcher at UW–Madison’s Wisconsin National Primate Research Center. “Eventually, as the disease progresses and their motor symptoms get worse, they are back to not having enough dopamine, and side effects of the drugs appear.”

Scientists have tried with some success to treat later-stage Parkinson’s in patients by implanting cells from fetal tissue, but research and outcomes were limited by the availability of useful cells and interference from patients’. Zhang’s lab has spent years learning how to dial donor cells from a patient back into a stem cell state, in which they have the power to grow into nearly any kind of cell in the body, and then redirect that development to create neurons.

The idea is very simple,” Zhang says. “When you have stem cells, you can generate the right type of target cells in a consistent manner. And when they come from the individual you want to graft them into, the body recognizes and welcomes them as their own.

Source: https://news.wisc.edu/