By using magnetic brain stimulation on patients with fibromyalgia, French researchers say they were able to improve some of the patients’ symptoms.

Specifically, the technique, called transcranial magnetic stimulation, raised quality of life and emotional and social well-being among patients suffering from the condition, the researchers found in a small study.

"This improvement is associated with an increase in brain metabolism, which argues for a physical cause for this disorder and for the possibility of changes in areas of the brain to improve the symptoms," said lead researcher Dr. Eric Guedj, of Aix-Marseille University and the National Center for Scientific Research, in Marseille.

"Previous studies in patients with fibromyalgia have suggested an alteration of brain areas is involved in the regulation of pain and emotion," he said.

The objective of this study was to demonstrate that it is possible to modulate these brain areas using transcranial magnetic stimulation to correct brain abnormalities and improve patients’ symptoms, Guedj said.

During treatment, patients wear a cap lined with electrodes that send small electric charges to targeted areas of the brain. The idea is to stimulate these areas and alter how they react.

The report was published March 26 in the journal Neurology.

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Amyotrophic lateral sclerosis, also known as Lou Gehrig’s disease, is marked by a cascade of cellular and inflammatory events that weakens and kills vital motor neurons in the brain and spinal cord. The process is complex, involving cells that ordinarily protect the neurons from harm. Now, a new study by scientists in The Research Institute at Nationwide Children’s Hospital points to a potential culprit in this good-cell-gone-bad scenario, a key step toward the ultimate goal of developing a treatment.

Motor neurons, or nerve cells, in the brain and spinal cord control the function of muscles throughout the body. In amyotrophic lateral sclerosis (ALS), motor neurons die and muscles weaken. Patients gradually lose the ability to move and as the disease progresses, are unable to breathe on their own. Most people with ALS die from respiratory failure within 3 to 5 years from the onset of symptoms.

For the study, published recently online in Neuron, researchers examined a protein involved in transcriptional regulation, called nuclear factor-kappa B (NF-κB), known to play a role in the neuroinflammatory response common in ALS. NF-κB has also been linked to cancer and a number of other inflammatory and autoimmune diseases.

Using animal models, the researchers studied disease progression in mice in which NF-κB had been inhibited in two different cell types — astrocytes, the most abundant cell type in the human brain and supporters of neuronal function; and microglia, macrophages in the brain and spinal cord that act as the first and main form of defense against invading pathogens in the central nervous system. Inhibiting NF-κB in microglia in mice slowed disease progression by 47 percent, says Brian Kaspar, MD, a principal investigator in the Center for Gene Therapy at Nationwide Children’s and senior author of the new study.

“The field has identified different cell types in addition to motor neurons involved in this disease, so one of our approaches was to find out what weapons these cells might be using to kill motor neurons,” Dr. Kaspar says. “And our findings suggest that the microglia utilize an NF-κB-mediated inflammatory response as one of its weapons.”

Inhibiting the protein in astrocytes had no impact on disease progression, so the search for the weapons that cell type uses against motor neurons continues. These preliminary findings also don’t tell scientists how or why NF-κB turns the ordinarily protective microglia into neuron-killing molecules. But despite the mysteries that remain, the study moves scientists closer to finding a treatment for ALS.

The search for an ALS therapy has been focused in two directions: identifying the trigger that leads to disease onset and understanding the process that leads to disease progression. Changes in motor neurons are involved in disease onset, but disease progression seems to be dictated by changes to astrocytes, microglia and oligodendrocytes. Some cases of ALS are hereditary but the vast majority of patients have no family ties to the disease. The complexity of the disease and the lack of a clear familiar tie make screening before disease onset nearly impossible, highlighting the importance of slowing the disease, Dr. Kaspar says.

“Focusing on stopping the changes that occur in astrocytes and microglia has clinical relevance because most people don’t know they’re getting ALS, says Dr. Kaspar, who also is an associate professor of pediatrics and neurosciences at The Ohio State University College of Medicine. “We have identified a pathway in microglia that may be targeted to ultimately slow disease progression in ALS and are exploring potential therapeutic strategies and may have broader implications for diseases such as Alzheimer’s and Parkinson’s Disease amongst others.”

(Source: nationwidechildrens.org)

Long-term brain damage caused by stroke could be reduced by saving cells called pericytes that control blood flow in capillaries, suggest researchers from Oxford University, UCL and the University of Copenhagen.

Until now, many scientists believed that blood flow within the brain was solely controlled by changes in the diameter of arterioles, blood vessels that branch out from arteries into smaller capillaries.

In this new study, the UK and Danish researchers reveal that the brain’s blood supply is in fact chiefly controlled by the narrowing or widening of capillaries as pericytes tighten or loosen around them.

Their study, published this week in the journal Nature, shows not only that pericytes are the main regulator of blood flow to the brain, but also that they tighten and die around capillaries after stroke. This significantly impairs blood flow in the long term, causing lasting damage to brain cells.

The scientists showed that certain chemicals can halve pericyte death from simulated stroke in the lab, and they hope to develop these into drugs to treat stroke victims.

'This discovery offers radically new treatment approaches for stroke,' says study co-author Professor Alastair Buchan, Dean of Medicine and Head of the Medical Sciences Division at Oxford University. 'Importantly, we should now be able to identify drugs that target these cells. If we are able to prevent pericytes from dying, it should help restore blood flow in the brain to normal and prevent the ongoing slow damage we see after a stroke which causes so much neurological disability in our patients.'

Professor David Attwell of UCL, who led the study, explains: ‘At present, clinicians can remove clots blocking blood flow to the brain if stroke patients reach hospital early enough. However, the capillary constriction produced by pericytes may, by restricting the blood supply for a long time, cause further damage to nerve cells even after the clot is removed. Our latest research suggests that devising drugs to prevent capillary constriction may offer new therapies for reducing the disability caused by stroke.’

The new research also gives insight into the mechanisms underlying the use of functional magnetic resonance imaging to detect blood flow changes in the brain.

'Functional imaging allows us to see the activity of nerve cells within the human brain but until now we didn't quite know what we were looking at,' says Professor Martin Lauritzen of the University of Copenhagen. 'We have shown that pericytes initiate the increase in blood flow seen when nerve cells become active. So we now know that functional imaging signals are caused by a pericyte-mediated increase of capillary diameter. Knowing exactly what functional imaging shows will help us to better understand and interpret what we see.'

(Source: ox.ac.uk)

Working with genetically engineered mice, Johns Hopkins neuroscientists report they have identified what they believe is the cause of the vast disintegration of a part of the brain called the corpus striatum in rodents and people with Huntington’s disease: loss of the ability to make the amino acid cysteine. They also found that disease progression slowed in mice that were fed a diet rich in cysteine, which is found in foods such as wheat germ and whey protein.

Their results suggest further investigation into cysteine supplementation as a candidate therapeutic in people with the disease.

Up to 90 percent of the human corpus striatum, a brain structure that moderates mood, movement and cognition, degenerates in people with Huntington’s disease, a condition marked by widespread motor and intellectual disability. And while the genetic mutation underlying Huntington’s disease has long been known, the precise cause of that degeneration has remained a mystery.

In a report on their discovery in the advanced online publication of Nature on March 26, the Johns Hopkins researchers, led by Solomon Snyder, M.D., tracked the degenerative process to the absence of an enzyme, cystathionine gamma lyase, or CSE.

"Usually it’s very hard, if not impossible, to develop straightforward mechanisms that explain what’s going on in a disease. What’s even harder is even if you can find a mechanism that causes a tissue to rot, usually there’s nothing you can do about it,” says Snyder, a professor of neuroscience at the Johns Hopkins University School of Medicine. “In this case, there is."

Huntington’s disease, an inherited disorder, does its damage because of abnormal DNA coding for the amino acid glutamine. Healthy individuals have some 15 to 20 DNA “repeats” in that part of their genetic code, while Huntington’s disease gene carriers have more than 36 — and often upward of 100. Children born to a parent carrier have a 50/50 chance of inheriting the disorder, and the greater the number of repeats, the earlier the age of onset of the incurable disorder.

Bindu Diana Paul, Ph.D., a molecular neuroscientist and faculty instructor in Snyder’s laboratory, was studying mice lacking CSE, which helps make the amino acid cysteine and hydrogen sulfide that moderate blood pressure and heart function. Paul, who had previous research experience with Huntington’s disease, says she was startled to observe that her mutant mice also behaved a lot like those with the disease.

When a normal mouse is dangled upside down from its tail, it will twist and turn and try to bite the offending hand, she explains. But her CSE-knockout mice stayed relatively still and clasped their paws together — the same behavior she’d observed in mice with the rodent equivalent of Huntington’s disease. “It looked like there was a neurological deficit,” Paul says. “But nobody had looked at CSE in the brain.”

Paul and Snyder began monitoring CSE in mouse and human brain tissues and found considerably less CSE in all diseased tissues. All people carry some normal huntingtin protein made by the Huntington’s disease gene, although the protein’s function remains elusive. But people with Huntington’s disease also carry mutant huntingtin proteins. Snyder and his team saw that the mutant proteins were attaching themselves to a crucial protein responsible for turning the CSE gene on or off, which ultimately led the diseased rodent and human brain tissues to be deprived of cysteine.

To see if loss of cysteine was directly responsible for the symptoms associated with Huntington’s disease, the Johns Hopkins team turned to readily available sources of the substance in everyday foods and fed mice a cysteine-rich diet.

The results, Paul says, were striking. When those mice were dangled from their tails, they resumed struggling, although with a bit less vigor than their healthy peers. They were able to grip an object with greater strength, and they took longer to fall off a balancing apparatus than CSE-knockout mice. Their life expectancies increased one to two weeks.

Snyder and Paul say they are cautiously optimistic about the results, noting that although they suggest a possible treatment for Huntington’s disease, it’s clear that a high cysteine diet merely slows rather than halts the progression of the disease. Moreover, the results in live mice may not occur in humans.

(Source: hopkinsmedicine.org)

The problems people with autism have with memory formation, higher-level thinking and social interactions may be partially attributable to the activity of receptors inside brain cells, researchers at Washington University School of Medicine in St. Louis have learned.

(Image caption: Learning, social interactions and higher-level thinking in people with autism may be adversely affected by receptors inside brain cells, scientists at Washington University School of Medicine have learned. The type of receptor they studied glows green on the surface of this cell. Inside the cell, the receptor covers a membrane stained red. Credit: Yuh-Jiin I. Jong)

Scientists were already aware that the type of receptor in question was a potential contributor to these problems – when located on the surfaces of brain cells. Until now, though, the role of the same type of receptor located inside the cell had gone unrecognized. Such receptors inside cells significantly outnumber the same type of receptors on the surface of cells.

The receptor under study, known as the mGlu5 receptor, becomes activated when it binds to the neurotransmitter glutamate, which is associated with learning and memory. This leads to chain reactions that convert the glutamate’s signal into messages traveling inside the cell.

In the new study, scientists working with cells in a dish linked mGlu5 receptors inside cells to processes that turn down the volume at which brain cells talk to each other. These volume changes, essential for learning and memory, may become exaggerated in people with autism.

Pharmaceutical companies have developed therapeutic compounds to decrease signaling associated with the mGlu5 receptor, moderating its effects on brain cells’ volume knobs. But the compounds were designed to target mGlu5 surface receptors. In light of the new findings, the scientists question if those drugs will reach the receptors inside cells.

“Our results suggest that to have the greatest therapeutic benefit, we may need to make sure we’re blocking all of this type of receptor, both inside and on the surface of the cell,” said senior investigator Karen O’Malley, PhD, professor of neurobiology.

The findings, published March 25 in The Journal of Neuroscience, also add a significant new dimension to basic brain cell function. Scientists have long assumed that brain cell receptors are only active on the surface of cells. The new study shows that receptors can be active inside cells, and their effects can be considerably different from the same receptors located on the cell surface.

“The traditional wisdom was that receptors inside the cell were either waiting to go to work on the surface or had just finished working there,” said O’Malley. “But when we compared how much of the mGlu5 receptor was on the surface of cells to how much was inside it, we were seeing so much more receptor inside the cell – at least 50 percent, and in some cases as much as 90 percent – that we wondered if the interior receptors had separate functions.”

In earlier studies, O’Malley and her collaborators showed that mGlu5 receptors on the cell surface sent completely different messages than the same receptors inside the cell.

The scientists knew that most autism studies were conducted with compounds that blocked mGlu5 receptors but could not get into the cell. To determine whether blocking inside receptors would have different effects, O’Malley collaborated with Yukitoshi Izumi, MD, PhD, research professor of psychiatry, and Charles F. Zorumski, MD, the Samuel B. Guze Professor and head of the Department of Psychiatry, who study cell-based models of learning and memory.

When the scientists examined these model systems using compounds that allowed them to activate only mGlu5 receptors within cells, they found that these receptors played a bigger role in turning down the volume of brain cell communications than did the cell surface receptors.

In the last few years, scientists have found that 20 or more types of brain cell receptors located on cell surfaces also are present at high levels inside cells, O’Malley noted.

“This should be a factor we consider when we design drugs to target brain cell receptors,” she said. “Do we want to reach cell surface receptors, receptors inside the cell or both?”

(Source: news.wustl.edu)