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Friday, February 5, 2016

Biologically Realistic Mathematical Model of How the Brain Makes Complex Decisions Created


Feb. 4, 2016
Cambridge, UK (Scicasts) — Researchers have built the first biologically realistic mathematical model of how the brain plans and learns when faced with a complex decision-making process.
Researchers have constructed the first comprehensive model of how neurons in the brain behave when faced with a complex decision-making process, and how they adapt and learn from mistakes.
The mathematical model, developed by researchers from the University of Cambridge, is the first biologically realistic account of the process, and is able to predict not only behaviour, but also neural activity. The results, reported in The Journal of Neuroscience, could aid in the understanding of conditions from obsessive compulsive disorder and addiction to Parkinson’s disease.
The model was compared to experimental data for a wide-ranging set of tasks, from simple binary choices to multistep sequential decision making. It accurately captures behavioural choice probabilities and predicts choice reversal in an experiment, a hallmark of complex decision making.
Our decisions may provide immediate gratification, but they can also have far-reaching consequences, which in turn depend on several other actions we have already made or will make in the future. The trouble that most of us have is how to take the potential long-term effects of a particular decision into account, so that we make the best choice.
There are two main types of decisions: habit-based and goal-based. An example of a habit-based decision would be a daily commute, which is generally the same every day. Just as certain websites are cached on a computer so that they load faster the next time they are visited, habits are formed by ‘caching’ certain behaviours so that they become virtually automatic.
An example of a goal-based decision would be a traffic accident or road closure on that same commute, forcing the adoption of a different route.
“A goal-based decision is much more complicated from a neurological point of view, because there are so many more variables – it involves exploring a branching set of possible future situations,” said the paper’s first author Dr. Johannes Friedrich of Columbia University, who conducted the work while a postdoctoral researcher in Cambridge’s Department of Engineering. “If you think about a detour on your daily commute, you need to make a separate decision each time you reach an intersection.”
Habit-based decisions have been thoroughly studied by neuroscientists and are fairly well-understood in terms of how they work at a neural level. The mechanisms behind goal-based decisions however, remain elusive.
Now, Friedrich and Dr. Máté Lengyel, also from Cambridge’s Department of Engineering, have built a biologically realistic solution to this computational problem. The researchers have shown mathematically how a network of neurons, when connected appropriately, can identify the best decision in a given situation and its future cumulative reward.
“Constructing these sorts of models is difficult because the model has to plan for all possible decisions at any given point in the process, and computations have to be performed in a biologically plausible manner,” said Friedrich. “But it’s an important part of figuring out how the brain works, since the ability to make decisions is such a core competence for both humans and animals.”
The researchers also found that for making a goal-based decision, the synapses which connect the neurons together need to ‘embed’ the knowledge of how situations follow on from each other, depending on the actions that are chosen, and how they result in immediate reward.
Crucially, they were also able to show in the same model how synapses can adapt and re-shape themselves depending on what did or didn’t work previously, in the same way that it has been observed in human and animal subjects.
“By combining planning and learning into one coherent model, we’ve made what is probably the most comprehensive model of complex decision-making to date,” said Friedrich. “What I also find exciting is that figuring out how the brain may be doing it has already suggested us new algorithms that could be used in computers to solve similar tasks,” added Lengyel.
The model could be used to aid in the understanding of a range of conditions. For instance, there is evidence for selective impairment in goal-directed behavioural control in patients with obsessive compulsive disorder, which forces them to rely instead on habits. Deep understanding of the underlying neural processes is important as impaired decision making has also been linked to suicide attempts, addiction and Parkinson's disease.
Article adapted from a University of Cambridge news release. The original article is licensed under a Creative Commons Licence.
https://scicasts.com/neuroscience/2061-computational-neuroscience/10677-biologically-realistic-mathematical-model-of-how-the-brain-makes-complex-decisions-created/?highlight=WyJwYXJraW5zb24ncyIsInBhcmtpbnNvbiIsInBhcmtpbnNvbidzXHUyMDFkLCIsInBhcmtpbnNvbidzLWFmZmVjdGVkIiwicGFya2luc29uJ3MuXHUyMDFkIiwicGFya2luc29uJ3MtbGlrZSIsInBhcmtpbnNvbidzLFx1MjAxZCIsImRpc2Vhc2UiLCJkaXNlYXNlJ3MiLCJkaXNlYXNlJy4iLCInZGlzZWFzZSIsImRpc2Vhc2UnIiwicGFya2luc29uJ3MgZGlzZWFzZSJd

Parkinson’s Balance Problems May Be Evident Decades Before Disease Diagnosed


BY DANIELA SEMEDO, PHD

People with Parkinson’s disease have a higher risk of bad falls and hip fractures as early as 26 years before diagnosis, partly because of a poorer sense of balance that might be an early sign of the illness, according to a study published in the journal PLOS Medicine and titled “Risk of Injurious Fall and Hip Fracture up to 26 years before the Diagnosis of Parkinson Disease: Nested Case–Control Studies in a Nationwide Cohort.”

Parkinson’s disease (PD) is a progressive neurological disorder caused by the gradual loss of the nerve cells that usually produce dopamine, a neurotransmitter that regulates the body’s motor functions. Evidence from studies has shown that low muscle strength in late adolescence is linked with PD diagnosed 30 years later.
To investigate if such lower muscle strength may also translate into increased risks of falls and fractures before a PD diagnosis, researchers looked at 24,412 adults — a cohort taken from the Swedish National Patient Register —  diagnosed with PD between 1988 and 2012. All patients were matched with up to 10 controls. During an average study period of 20 years prior to a PD diagnosis, 18 percent of PD patients, and 11.5 percent of controls, had at least one fall that caused an injury that required emergency care.
The results revealed reduced muscular strength in the arms could be detected, on average, 30 years before a PD diagnosis. Moreover, this reduced muscular strength could also be associated with an increased risk of hip fractures more than 15 years before PD diagnosis, and injuring falls up to 10 years before diagnosis. Signs of gradual dysfunction in balance reactions and impaired mobility were also present at an early stage.
These findings suggest that clinically relevant neurodegenerative impairment could be present many years before the clinical onset of the disease. “We asked ourselves if fall-related injuries at an early age could be a warning sign of the deteriorating balance that is characteristic to Parkinson’s disease,” Helena Nyström, a doctoral student at the Department of Community Medicine and Rehabilitation and co-author of the article, said in a news release. “By investigating health data from registers, we could see a correlation between individuals who were later diagnosed with Parkinson’s and who were more often involved in injurious falls. It was also shown that the higher risk of hip fractures could be measured more than two decades before the diagnosis.”
http://parkinsonsnewstoday.com/2016/02/05/high-risk-of-falling-an-early-sign-of-parkinsons/

Counting Parkinson’s patients one by one- Important!

February 04, 2016,
WE NEED TO BE COUNTED

CONTACT YOUR REPRESENTATIVES

WE NEED TO KNOW AN ACCURATE COUNT OF PEOPLE WITH PARKINSON'S DISEASE IN THE U.S.













If you ask how many people in the United States are living with Parkinson's disease, you can get a number anywhere from 500,000 to 1,500,000 or more, depending on the source. Why such a disparity in the numbers?
 
Why, despite advances in research and so many improvements in medical data collection, don't we know more about Parkinson's disease?

The answer is that we simply don’t know. We don’t know, in large part, because there is no national database on Parkinson’s disease and other neurological disorders in the United States. 

An integrated national database would help answer many questions, including: does the disease affect more men or more women? How many Parkinson’s patients should be classified as early onset? What effect does the environment have on the disease? How many different types of Parkinson’s disease exist?  


Parkinson’s is a progressive neurological disease. You may be familiar with Michael J. Fox and Muhammad Ali and the tremors and involuntary movements they exhibit. But not all people with Parkinson’s disease have tremors. Symptoms can vary widely, including many symptoms not readily seen, such as muscle stiffness, depression, and cognitive difficulties. 

Someone may not be able to tell from looking at me, but I have had Parkinson’s for several years and it has had a significant impact on my life. My diagnosis may not be uncommon, yet the intricacies of my experience are neither well understood nor well documented.



Our basic lack of data has far-reaching effects. Without complete information, policymakers devote insufficient funding for services and the research that can help us find new treatments and potential cures. Pharmaceutical companies choose other diseases in which to invest their research monies. Nonprofit organizations dedicate fewer resources for support services. Without data, the world of Parkinson’s treatment and services can be a mystery without much hope--and the same holds true for many other progressive neurological disorders.

The House-passed 21st Century Cures Act would create a neurological disease registry at the Centers for Disease Control. The overwhelming bipartisan effort in the House should not be wasted. I urge the Senate HELP committee to support similar legislation about the registry, the Advancing Research for Neurological Diseases Act.

Establishing a national database is a smart investment. Currently, Americans spend more than $500 billion per year treating neurological diseases. This database would cost $25 million over five years, and it would ensure that we are treating neurological diseases more effectively. Much of the additional funding for Parkinson’s would support research at our world-renowned institutions, including Massachusetts General Hospital and Harvard Medical School. 

The benefits of this bill should appeal to both Democrats and Republicans. As Newt Gingrich has pointed out, if we cannot effectively treat and prevent neurological diseases such as Parkinson's and Alzheimer's in the near future, the growing prevalence of these diseases among the aging Baby Boomer generation could soon cost the nation trillions more in healthcare and support services. 

If the Senate does not act soon, the issue could become lost in the fray of a presidential election year. What we don’t know is hurting us and the solution is clear. Once we know more about patients with Parkinson’s and other neurological diseases, we will be closer to finding a cure and improving lives.

http://thehill.com/blogs/congress-blog/healthcare/268136-counting-parkinsons-patients-one-by-one

Saliva may provide early test for Parkinson's disease

A saliva gland test could become a new way to test for early Parkinson's disease, according to research published in Movement Disorders.

February 5, 2016


Parkinson's disease can go undetected for some time, but the new test could help patients obtain an early diagnosis.

The Parkinson's Disease Foundation (PDF) note that a million Americans may be living with Parkinson's disease, and around 60,000 new cases are diagnosed each year, while thousands go undetected.
Parkinson's mostly manifests in older people, but 4% of cases are diagnosed before the age of 50 years. The risk is one and a half times higher for men than for women.
The degenerative neurological disorder affects movement, sleep, walking, balance,blood pressure and smell. There is no cure, but medications can relieve the symptoms.
The first and best-known sign of the disease is often just a small tremor in one hand. Stiffness or slowing of movement may occur, which gradually gets worse.
No test so far has been able to diagnose Parkinson's disease accurately. The basis for diagnosis is currently medical history, signs and symptoms, a neurological examination and exclusion of other conditions.

Submandibular gland biopsy may provide early diagnosis
Researchers from the Mayo Clinic in Phoenix, AZ, and Banner Sun Health Research Institute in Sun City, AZ, carried out the current study. They had previously found that up to 45% of patients in the early stages may receive an incorrect diagnosis.
The team wanted to see if a procedure termed "transcutaneous submandibular gland biopsy" could provide an answer. In this procedure, a core of gland tissue is extracted by inserting a needle into a salivary gland under the jaw.
The scientists were searching for a protein in the cells that could indicate early Parkinson's disease. They took the biopsies from one salivary gland to test for it. In earlier tests, they had found that that the same biopsy test could detect the abnormal protein in 9 out of 12 patients with advanced Parkinson's.
The new study involved 25 patients who had the disease for less than 5 years and 10 healthy individuals.
Of the 25 subjects, 19 had sufficient tissue for the study. The researchers tested the biopsied tissues to see if they contained the Parkinson's protein. The researchers then compared the results with those of the healthy controls.

The protein was found to be present in 14 out of 19 patients.
Study co-author Dr. Thomas Beach, PhD, a neuropathologist with Banner Sun Health Research Institute, says:
"This procedure will provide a much more accurate diagnosis of Parkinson's disease than what is now available. One of the greatest potential impacts of this finding is on clinical trials, as at the present time some patients entered into Parkinson's clinical trials do not necessarily have Parkinson's disease and this is a big impediment to testing new therapies."
Study author Dr. Charles Adler, PhD, neurologist and professor of neurology at the Mayo Clinic, adds that using submandibular gland biopsies to test for early Parkinson's disease may help many people because, currently, testing after 10 years gives a far more reliable diagnosis than early testing.

The team hopes for further studies to expand understanding of the disease and to develop better treatments.

http://www.topix.com/health/parkinsons-disease/2016/02/saliva-may-provide-early-test-for-parkinsons-disease

10 Ways You Can Increase Dopamine Levels In The Brain Without Medication