June 25, 2009, 7:26 PM CT

Remembering what to remember and what to forget

People in very early stages of Alzheimer's disease already have trouble focusing on what is important to remember, a UCLA psychology expert and his colleagues report.

"One of the first telltale signs of Alzheimer's disease appears to be not memory problems, but failure to control attention," said Alan Castel, UCLA assistant professor of psychology and main author of the study.

The study consisted of three groups: 109 healthy elderly adults (68 of them female), with an average age of just under 75; 54 elderly adults (22 of them female) with very mild Alzheimer's disease, who were functioning fine in their daily lives, with an average age of just under 76; and 35 young adults, with an average age of 19.

They were presented with eight lists of 12 words, one word at a time, each paired with a point value from 1 to 12. A new word with its value was presented on a screen every second. The words were common, like "table," "wallet" and "apple." They were given 30 seconds to recall the words, and were told to maximize their scores, by focusing on remembering the high-value words.

The young adults were selective, remembering more of the high-value words than the low-value words. They recalled an average of 5.7 words out of 12. The healthy elderly adults remembered fewer words, an average of 3.5, but were equally selective in recalling the high-value words......... Posted by: Daniel      Read more         Source

June 23, 2009, 5:08 PM CT

Morning people and night owls

Are you a "morning person" or a "night owl?".

Researchers at the University of Alberta have observed that there are significant differences in the way our brains function depending on whether we're early risers or night owls.

Neuroresearchers in the Faculty of Physical Education and Recreation looked at two groups of people: those who wake up early and feel most productive in the morning, and those who were identified as evening people, those who typically felt livelier at night. Study participants were initially grouped after completing a standardized questionnaire about their habits.

Using magnetic resonance imaging-guided brain stimulation, researchers tested muscle torque and the excitability of pathways through the spinal cord and brain. They observed that morning people's brains were most excitable at 9 a.m. This slowly decreased through the day. It was the polar opposite for evening people, whose brains were most excitable at 9 p.m.

Other major findings:

• Evening people became physically stronger throughout the day, but the maximum amount of force morning people could produce remained the same.
• The excitability of reflex pathways that travel through the spinal cord increased over the day for each of these two groups.

........ Posted by: Daniel      Read more         Source

June 12, 2009, 5:24 AM CT

Why smoking increases the risk of heart disease and strokes?

Scientists at Charles Drew University of Medicine and Science in Los Angeles and Western University of Health Sciences in Pomona have discovered a reason why smoking increases the risk of heart disease and strokes.

The study, which will be presented Thursday, June 11 at The Endocrine Society's 91st annual meeting in Washington, D.C., observed that nicotine in cigarettes promotes insulin resistance, a pre-diabetic condition that raises blood sugar levels higher than normal. People with pre-diabetes are at greater risk of developing cardiovascular disease.

Theodore Friedman, MD, Ph.D., chief of the endocrinology division at Charles Drew University, said the findings help explain a "paradox" that links smoking to heart disease.

Smokers experience a high degree of cardiovascular deaths, Friedman said. "This is surprising considering both smoking and nicotine may cause weight loss and weight loss should protect against cardiovascular disease".

The scientists studied the effects of twice-daily injections of nicotine on 24 adult mice over two weeks. The nicotine-injected mice ate less food, lost weight and had less fat than control mice that received injections without nicotine.

"Our results in mice show that nicotine administration leads to both weight loss and decreased food intake," Friedman said. "Mice exposed to nicotine have less fat. In spite of this, mice have abnormal glucose tolerance and are insulin resistant (pre-diabetes)."........ Posted by: Daniel      Read more         Source

June 11, 2009, 5:15 AM CT

What causes multiple sclerosis?

Over 100,000 people suffer from multiple sclerosis in Gera number of alone. Despite intensive research, the factors that trigger the disease and influence its progress remain unclear. Researchers from the Max Planck Institute of Neurobiology in Martinsried and an international research team have succeeded in attaining three important new insights into the disease. It would appear that B cells play an unexpected role in the spontaneous development of multiple sclerosis and that especially aggressive T cells are activated by different proteins. Furthermore, a new animal model is helping the researchers to understand the emergence of the most common form of the disease in Gera number of. (Nature Medicine, May 31, 2009 & Journal of Experimental Medicine, June 1, 2009).

Multiple Sclerosis (MS) poses enormous problems for both patients and doctors: it is the most common inflammatory disease of the central nervous system in our part of the world and often strikes patients at a relatively young age. In some patients it leads to severe disability. Moreover, despite decades of research on MS, the causes and course of the disease are still largely unclear.

There is much evidence to support the fact that MS is triggered by an autoimmune reaction: immune cells that should actually protect the body against threats like viruses, bacteria and tumours, attack the body's own brain tissue. New therapys now available can attenuate the harmful immune reaction and thus delay the progress of the disease. However, the more effective the therapy, the more serious its side effects. Therefore, it is a matter of extreme urgency that new forms of therapy be developed which can differentiate in a targeted way between the immune cells that cause the disease and those that should be protected. A better understanding of the disease is mandatory in order to achieve this......... Posted by: Daniel      Read more         Source

June 8, 2009, 10:10 PM CT

Fatal brain disease at work

University of Florida researchers have discovered why a paralyzing brain disorder speeds along more rapidly in some patients than others a finding that may finally give scientists an entry point toward an effective therapy for amyotrophic lateral sclerosis, often referred to as ALS or Lou Gehrig's disease.

Of more than 100 possible mutations of a single gene inherited by people with familial ALS, the mutations most inclined to produce clumps of problematic cellular debris known as "protein aggregates" appear to be linked to quicker progress of the disease, as per scientists with the University of Florida's McKnight Brain Institute writing online this week in Human Molecular Genetics

Meanwhile, in a separate study recently online in the Proceedings of the National Academy of Sciences, researchers describe how these protein clumps long considered a defining characteristic of ALS do not cause the disease, but appear later on, increasing in number between onset of weakness and paralysis in patients.

Together, these findings suggest that the deadly course of the disease is associated with the formation of these protein clumps, even though the sickness may have been well under way.

"Blocking aggregation of these proteins could be a therapeutic target for individuals with this genetic mutation," said David Borchelt, Ph.D., a professor of neuroscience and director of the SantaFe HealthCare Alzheimer's Disease Research Center at UF's McKnight Brain Institute. "Right now, there is little that can be done to help these patients"......... Posted by: Daniel      Read more         Source

June 5, 2009, 5:03 AM CT

Pesticide Exposure and Parkinson's Disease

The cause of Parkinson's disease (PD), the second most frequent neurodegenerative disease after Alzheimer's disease, is unknown, but in most cases it is believed to involve a combination of environmental risk factors and genetic susceptibility. Laboratory studies in rats have shown that injecting the insecticide rotenone leads to an animal model of PD and several epidemiological studies have shown an association between pesticides and PD, but most have not identified specific pesticides or studied the amount of exposure relating to the association.

A new epidemiological study involving the exposure of French farm workers to pesticides observed that professional exposure is linked to PD, particularly for organochlorine insecticides. The study is published in Annals of Neurology, the official journal of the American Neurological Association.

Led by Alexis Elbaz M.D., Ph.D., of Inserm, the national French institute for health research in Paris, and University Pierre et Marie Curie (UPMC, Paris 6), the study involved individuals affiliated with the French health insurance organization for agricultural workers who were frequently exposed to pesticides in the course of their work. Occupational health physicians constructed a detailed lifetime exposure history to pesticides by interviewing participants, visiting farms, and collecting a large amount of data on pesticide exposure. These included farm size, type of crops, animal breeding, which pesticides were used, time period of use, frequency and duration of exposure per year, and spraying method......... Posted by: Daniel      Read more         Source

June 3, 2009, 5:13 AM CT

How the Brain Processes What the Eye Sees

Scientists at the Center for Molecular and Behavioral Neuroscience (CMBN) at Rutgers University in Newark have identified the need to develop a new framework for understanding "perceptual stability" and how we see the world with their discovery that visual input obtained during eye movements is being processed by the brain but blocked from awareness.

The process of seeing requires the eyes to move so light can hit the photoreceptors at the center of each retina, which then pass that information to the brain. If we were cognizant of the stimulus that passes before the eyes during the two to three times they move every second, however, vision would consist of a series of sensations of rapid motion rather than a stable perception of the world. To achieve perceptual stability, current theory has held that visual information gained during an eye movement is eliminated, as if cut off by a camera's shutter, and removed from processing.

As published in Current Biology (http://www.cell.com/current-biology), significant new research conducted by assistant professor Bart Krekelberg and post-doctoral researcher Tamara L. Watson now shows that theory of saccadic suppression is incorrect and what the brain is doing instead is processing information gained during eye movement but blocking it from being reported......... Posted by: Daniel      Read more         Source

May 26, 2009, 6:34 PM CT

The evolution of migraine

Patients living with migraine have strong reason for new optimism concerning a positive future. Two review articles and an accompanying editorial, "The Future of Migraine: Beyond Just Another Pill," in the current issue of Mayo Clinic Proceedings, are the basis for an ironic premise.

"Migraine is a potentially chronic, progressive disease that substantially affects patients, families, workplaces, and society," as per the editorial written by Roger Cady, M.D., of the Headache Care Center in Springfield, Mo. "Ironically, this is the springboard for renewed optimism of a more positive future for patients living with migraine."

Traditionally, Dr. Cady explains, migraine has been considered a pain disorder involving separate or even sporadic episodes. Now, the condition is defined as an all-encompassing and progressive disease that negatively affects all aspects of an individual's life. Migraine can erode quality of life during what should be a person's most productive years, as per Dr. Cady. Because migraine patients' quality of life has not improved at a pace with medical advances, research is addressing the overall severity and potential progressive nature of migraine, particularly migraine episodes as a forerunner of chronic migraine.

As per the three articles, these new insights and understandings are requiring professionals to explore well beyond traditional migraine management. "Understanding migraine as a potentially chronic disease mandates a collaborative health care model with patients and health care professionals working in a partnership toward common therapeutic goals," writes Dr. Cady, specifically intervention and prevention. Physicians and patients must be encouraged to be partners, he says, and assessment must go far beyond the doctor just asking, "How are your migraines?" The models must include an invitation to comprehend and address all migraine-related health issues facing patients, Dr. Cady writes. In addition, understanding the evolutionary "stages" of migraine from sporadic to persistent offers an opportunity to develop new therapies that individualize and personalize care......... Posted by: Daniel      Read more         Source

May 26, 2009, 6:30 PM CT

pioglitazone against multiple sclerosis

A drug currently FDA-approved for use in diabetes shows some protective effects in the brains of patients with relapsing remitting multiple sclerosis, scientists at the University of Illinois at Chicago College of Medicine report in a study currently available online in the Journal of Neuroimmunology

In a small, double-blinded clinical trial, patients with relapsing remitting multiple sclerosis were assigned to take pioglitazone (a drug commercially known as Actos used to treat type-2 diabetes) or a placebo. Patients continued their normal course of treatment during the trial.

Standard neurological tests were done initially, as were MRI scans to provide baseline values for lesions typically seen in MS patients. The patients were reviewed every two months, and blood samples were taken. Repeat MRI scans were done after five months and again after one year.

Patients taking pioglitazone showed significantly less loss of gray matter over the course of the one-year trial than patients taking placebo. Of the 21 patients who finished the study, patients taking pioglitazone had no adverse reactions and, further, found taking pioglitazone, which is administered in an oral tablet, easy.

"This is very encouraging," said Douglas Feinstein, research professor of anesthesiology at UIC. "Gray matter in the brain is the part that is rich in neurons. These preliminary results suggest that the drug has important effects on neuronal survival"......... Posted by: Daniel      Read more         Source

May 22, 2009, 5:13 AM CT

Identifying Alzheimers disease early

Analyzing MRI studies of the brain with software developed at the Martinos Center for Biomedical Imaging at Massachusetts General Hospital (MGH) may allow diagnosis of Alzheimer's disease and of mild cognitive impairment, a lesser form of dementia that precedes the development of Alzheimer's by several years. In their report that will appear in the journal Brain and has been released online, the MGH/Martinos team show how their software program can accurately differentiate patients with mild cognitive impairment or Alzheimer's disease from normal elderly individuals based on anatomic differences in brain structures known to be affected by the disease.

"Traditionally Alzheimer's has been diagnosed based on a combination of factors such as a neurologic exam, detailed medical history and written tests of cognitive functioning with neuroimaging used primarily to rule out other diseases such as stroke or a brain tumor," says Rahul Desikan MD, PhD, of the Martinos Center and Boston University School of Medicine, main author of the Brain paper. "Our findings show the feasibility and importance of using automated, MRI-based neuroanatomic measures as a diagnostic marker for Alzheimer's disease."

The scientists note that mild cognitive impairment occurs in about 20 percent of elderly individuals as a number of as 40 percent of those over 85 80 percent of whom develop Alzheimer's within five or six years. Since drugs that may slow the progression of Alzheimer's are in development, the ability to treat patients in the earliest stages of the disease may significantly delay progression to dementia. To investigate whether MR imaging can produce diagnostic markers for mild cognitive impairment and Alzheimer's disease, the research team used FreeSurfer an openly available imaging software package developed at the Martinos Center and the University of California at San Diego to examine many neuroanatomic regions across a range of normal individuals and patients with mild cognitive impairment and Alzheimer's disease......... Posted by: Daniel      Read more         Source

May 20, 2009, 5:04 AM CT

Promise for epilepsy treatment

University of Minnesota McKnight professor and Director of Center for Neuroengineering Bin He has developed a new technique that has led to preliminary successes in noninvasive imaging of seizure foci. He's technique promises to play an important role in the therapy of epileptic seizures.

To view a video explaining the procedure, visit: http://www1.umn.edu/urelate/newsservice/Multimedia_Videos/bin_he.htm.

He's research, called Functional Neuroimaging, has completed its first round of testing in epilepsy data collected at the Mayo Clinic. He's medical device images the brain while epilepsy patients have a seizure and then allows surgeons to identify the network where the seizure is caused.

Approximately one-third of people who suffer from epileptic seizures cannot be treated by medication, and this process could lead to further advancements in surgical therapy......... Posted by: Daniel      Read more         Source

May 15, 2009, 5:25 AM CT

Heart disorder and Alzheimer's disease

Scientists at Intermountain Medical Center in Salt Lake City think that they have made a breakthrough correlation between atrial fibrillation, a fairly common heart rhythm disorder, and Alzheimer's disease, the leading form of dementia among Americans.

In a study presented Friday, May 15, at "Heart Rhythm 2009," the annual scientific sessions of the Heart Rhythm Society in Boston, scientists unveiled findings from the study of more than 37,000 patients that showed a strong relationship between atrial fibrillation and the development of Alzheimer's disease.

The study, which drew upon information from the Intermountain Heart Collaborative Study, a vast database from hundreds of thousands of patients treated at Intermountain Healthcare hospitals, found:

Patients with atrial fibrillation were 44 percent more likely to develop dementia than patients without the heart disorder.

Younger patients with atrial fibrillation were at higher risk of developing all types of dementia, especially Alzheimer's. Atrial fibrillation patients under age 70 were 130 percent more likely to develop Alzheimer's.

Patients who have both atrial fibrillation and dementia were 61 percent more likely to die during the study period than dementia patients without the rhythm problem......... Posted by: Daniel      Read more         Source

May 13, 2009, 5:14 AM CT

How to build a bigger brain

Push-ups, crunches, gyms, personal trainers people have a number of strategies for building bigger muscles and stronger bones. But what can one do to build a bigger brain? .

Meditate.

That's the finding from a group of scientists at UCLA who used high-resolution magnetic resonance imaging (MRI) to scan the brains of people who meditate. As per a research findings reported in the journal NeuroImage and currently available online (by subscription), the scientists report that certain regions in the brains of long-term meditators were larger than in a similar control group.

Specifically, meditators showed significantly larger volumes of the hippocampus and areas within the orbito-frontal cortex, the thalamus and the inferior temporal gyrus all regions known for regulating emotions.

"We know that people who consistently meditate have a singular ability to cultivate positive emotions, retain emotional stability and engage in mindful behavior," said Eileen Luders, main author and a postdoctoral research fellow at the UCLA Laboratory of Neuro Imaging. "The observed differences in brain anatomy might give us a clue why meditators have these exceptional abilities." .

Research has confirmed the beneficial aspects of meditation. In addition to having better focus and control over their emotions, a number of people who meditate regularly have reduced levels of stress and bolstered immune systems. But less is known about the link between meditation and brain structure......... Posted by: Daniel      Read more         Source

May 11, 2009, 9:24 PM CT

Genetic cause of of breast cancer

The discovery of tumor-suppressor genes has been key to unlocking the molecular and cellular mechanisms leading to uncontrolled cell proliferation the hallmark of cancer. Often, these genes will work in concert with others in a complex biochemical system that keeps our cells growing and dividing, disease free.

Now scientists at the University of North Carolina at Chapel Hill School of Medicine and UNC Lineberger Comprehensive Cancer Center have observed that defects in one gene, called p18, may override the rest, eventually leading to cancer.

This discovery, combined with new laboratory techniques, will help researchers identify and test new therapys for luminal-type tumors, which account for between 70 and 80 percent of all breast cancers, but are generally slower growing than other types.

The results of the research appear in the May 2009 issue of Cancer Cell

Defects in the p18 gene have been observed in different types of human cancer. Senior study author Yue Xiong, Ph.D., William R. Kenan Jr. Distinguished Professor of biochemistry and biophysics, observes, "When this gene is not expressed or is deleted, cells have no braking mechanism. They will continue to grow and divide until they turn into cancer".

Xiong and colleagues specifically targeted the role that p18 plays in the development of luminal breast cancers. Using genetically-engineered mice with deletion of p18 genes, they created a highly reliable model of human breast cancers. The scientists tested their model by analyzing the gene in samples from approximately 300 human patients with breast cancer, proving that the decreased expression of the p18 gene is highly correlated with the development of luminal tumors......... Posted by: Daniel      Read more         Source

May 11, 2009, 9:22 PM CT

Brain's problem-solving function at work

A new University of British Columbia study finds that our brains are much more active when we daydream than previously thought.

The study, reported in the Proceedings of the National Academy of Sciences, finds that activity in numerous brain regions increases when our minds wander. It also finds that brain areas linked to complex problem-solving previously thought to go dormant when we daydream are in fact highly active during these episodes.

"Mind wandering is typically linked to negative things like laziness or inattentiveness," says main author, Prof. Kalina Christoff, UBC Dept. of Psychology. "But this study shows our brains are very active when we daydream much more active than when we focus on routine tasks".

For the study, subjects were placed inside an fMRI scanner, where they performed the simple routine task of pushing a button when numbers appear on a screen. The scientists tracked subjects' attentiveness moment-to-moment through brain scans, subjective reports from subjects and by tracking their performance on the task.

The findings suggest that daydreaming which can occupy as much as one third of our waking lives is an important cognitive state where we may unconsciously turn our attention from immediate tasks to sort through important problems in our lives......... Posted by: Daniel      Read more         Source

May 4, 2009, 5:10 AM CT

Memory in Alzheimer's disease

Even very early in Alzheimer's disease, people become less efficient at separating important from less important information, a newly released study has observed.

Knowing this, clinicians appears to be able to train people in the early stages of Alzheimer's to remember high-value information better, as per a report in the recent issue of Neuropsychology, published by the American Psychological Association.

Remembering what's most important is central to daily life. For example, if you went to the grocery store but left your shopping list at home, you'd at least want to remember the milk and bread, if not the jam. Or, when packing for a trip, you'd want to remember your wallet and tickets more than your slippers or belt.

Participants in the study were recruited from the Washington University in St. Louis Alzheimer's Disease Research Center. They included 109 healthy elderly adults (average age of almost 75), 41 people with very mild (very early) Alzheimer's disease (average age of almost 76), 13 people with mild (early) Alzheimer's (average age of almost 77), and 35 younger adults (all 25 or under, average age of almost 20).

The scientists asked participants to study and learn neutral words that were randomly assigned different point values. When asked to recall the items, participants were asked to maximize the total value. All participants, even those with Alzheimer's, recalled more high-value than low-value items. However, the Alzheimer's groups were significantly less efficient than their healthy age peers at remembering items as per their value. It meant they no longer maximized learning and memory, which in healthy people are fairly efficient processes......... Posted by: Daniel      Read more         Source

April 30, 2009, 5:18 AM CT

Magnetic stimulation therapy for migraine

A new UCSF study examining the mechanism of a novel treatment that uses magnetic pulses to treat chronic migraine sufferers showed the therapy to be a promising alternative to medication.

The treatment is called transcranial magnetic stimulation, or TMS. Study findings were presented today (April 29, 2009) during the annual American Academy of Neurology scientific meeting in Seattle.

In a prior randomized controlled clinical study by Ohio State University Medical Center, TMS was used to treat patients who suffer from migraine with aura, a condition in which a variety of mostly visual sensations come before or accompany the pain of a migraine attack. The study showed that TMS therapy was superior to the placebo given to the control group. Patients were pain-free at follow-up intervals of 2, 24 and 48 hours.

In the newly released study, conducted in rats, UCSF scientists focused on understanding the mechanism of action of TMS treatment -- how the therapy interacted with the brain to produce the pain-free outcomes of patients in the prior study.

The UCSF research identified potential opportunities to enhance therapy strategies in patients. One example, the study team noted, was that factors such as time and peak intensity of stimulation appears to be important components in the brain's response to TMS......... Posted by: Daniel      Read more         Source

April 29, 2009, 5:02 AM CT

Preventing migraine

When migraine strikes, because of severe pain, often accompanied by nausea and sensitivity to light and sound, sufferers are effectively disabled for up to 72 hours. Since they are forced to stop what they are doing until the pain and other symptoms subside, migraine causes a significant loss in productivity at work and the personal lives of those affected. Migraineurs particularly the 25% of migraineurs who experience more than three migraine attacks per month are looking to drug developers to provide new drugs to prevent migraine attacks before they start. In the U.S. alone, approximately 30 million people suffer from migraines and the cost to employers has been estimated at $13 billion annually in lost productivity. Currently, several types of drugs, like generic beta blockers, calcium channel blockers, tricyclic antidepressants and anti-epileptic drugs, some of which are used off-label, are given to prevent migraines. However, a number of patients have only a partial response to these products, a number of of which have troubling side effects. Nevertheless, a number of migraine patients use existing drugs, illustrating how badly new drugs are needed.

Given the role of glutamate in the pathophysiology of migraine, the future of migraine prophylaxis, may lie in modulating one of the receptors in the glutamate system, mGluR5......... Posted by: Daniel      Read more         Source

April 29, 2009, 5:00 AM CT

Stroke predictors in black patients

Predictors of atrial fibrillation (AF or afib) might offer physicians a better way to prevent stroke in blacks, as per a newly released study done by scientists at Wake Forest University School of Medicine.

AF is an irregular and often rapid heart rate that usually causes poor blood flow to the body, as well as symptoms of heart palpitations, shortness of breath and weakness. Despite low reported prevalence of AF a main risk factors for stroke in black patients, they suffer strokes five times more often than white patients and die from them two times more often.

That paradox might result from limitations in the methods (electrocardiograms (ECG) or self-report) used to detect AF, said Elsayed Z. Soliman, M.D., M.Sc. M.S., associate director of the Epidemiological Cardiology Research Center (EPICARE) at the School of Medicine and main author of the study.

"The limitations stem from the fact that AF is intermittent in at least 30 percent of patients, and most patients are not aware if they have AF or not," Soliman said. "Trying to detect AF using an ECG, or simply counting on patients to know if they have it, leads to under-diagnosis of the condition most of the time. Our research suggests that being proactive in predicting it appears to be a better approach"......... Posted by: Daniel      Read more         Source

April 28, 2009, 5:23 AM CT

Novel role of protein in generating amyloid-beta peptide

A defining hallmark of Alzheimer's disease is the accumulation of the amyloid β protein (Aβ), otherwise known as "senile plaques," in the brain's cortex and hippocampus, where memory consolidation occurs. Scientists at the University of California, San Diego School of Medicine have identified a novel protein which, when over-expressed, leads to a dramatic increase in the generation of Aβ. Their findings, which indicate a potential new target to block the accumulation of amyloid plaque in the brain, would be reported in the May 1 issue of the Journal of Biological Chemistry

"The role of the multi-domain protein, RANBP9, suggests a possible new therapeutic target for Alzheimer's disease," said David E. Kang, PhD, assistant professor of neurosciences at UC San Diego and director of this study.

The neurotoxic protein Aβ is derived when the amyloid precursor protein (APP) is "cut" by two enzymes, β-secretase (or BACE) and γ-secretase (or Presenilin complex.) However, inhibiting these enzymes in order to stop the amyloid cascade has a number of negative side effects, as these enzymes also have various beneficial uses in brain cells. So the scientists looked for an alternative way to block the production of amyloid beta.

In order for cleavage to occur, the APP needs to travel to cholesterol-enriched sites within the cell membrane called RAFTS, where APP interacts with the two enzymes. It is this contact that the scientists sought to block......... Posted by: Daniel      Read more         Source