Posts tagged Neuroscience 2013

Research released today reveals a new model for a genetic eye disease, and shows how animal models — from fruit flies to armadillos and monkeys — can yield valuable information about the human brain. The findings were presented at Neuroscience 2013, the annual meeting of the Society for Neuroscience and the world’s largest source of emerging news about brain science and health.

Animal models have long been central in how we understand the human brain, behavior, and nervous system due to similarities in many brain areas and functions across species. Almost every major medical advance in the last century was made possible by carefully regulated, humane animal research. Today’s findings build on this rich history and demonstrate what animals can teach us about ourselves.

Today’s new findings show that:

• The nine-banded armadillo may serve as a model for certain types of progressive blindness. The animal’s poor eyesight mimics many human disorders and may shed light on new treatment approaches for such diseases (Christopher Emerling, BS, abstract 150.06, see attached summary).
• Analysis of a baboon population reveals particular genes that may be involved in creating the “folds” in the structure of the brain. These findings provide information on how human genes may have evolved to create the brain’s shape and function (Elizabeth Atkinson, BA, abstract 195.13, see attached summary).
• Monkeys and humans use similar brain pathways while processing decisions. Detailed analyses of similarities and differences in brain wiring could provide new insights into decision-making in humans (Franz-Xaver Neubert, abstract 18.03, see attached summary).

Other recent findings discussed show that:

• Use of powerful genetic tools in fruit flies is helping to reveal the basic building blocks of brain circuitry and function. This work is furthering our understanding of the human brain and may be helpful in developing medical diagnostic devices (Rachel Wilson, PhD, presentation 302, see attached speaker summary).
• Research in a tiny worm (C. elegans) has allowed scientists to map all of the connections between neurons in the species, including the pathways for movement, sex, and more. The findings offer new insights into how the human nervous system functions (Scott Emmons, PhD, presentation 009, see attached speaker summary).

“Neuroscience has always relied on responsible animal research to better understand how our brains and bodies develop, function, and break down,” said press conference moderator Leslie Tolbert, of the University of Arizona, whose work in insects provides insights into brain development. “Today’s studies reveal new ways that research on unlikely-seeming animals, such as armadillos, fruit flies, and worms, could have real impact on our understanding of the human brain and what can go wrong in disease.”

Scientists are gaining a new level of understanding of multiple sclerosis (MS) that may lead to new treatments and approaches to controlling the chronic disease, according to new research released today at Neuroscience 2013, the annual meeting of the Society for Neuroscience and the world’s largest source of emerging news about brain science and health.

MS is a severe, often crippling, autoimmune disease caused by the body’s immune system attacking the nervous system. Today, more than two million people worldwide suffer from MS and other neuroinflammatory diseases. MS usually strikes in early adulthood and manifests with symptoms including vision loss, paralysis, numbness, and fatigue. The disease can be intermittent or progressive and currently has no cure.

Today’s new findings show that:

• Scientists are one step closer to understanding how antibodies in the blood stream break past the brain’s protective barrier to attack the optic nerves, spinal cord, and brain, causing the symptoms of neuromyelitis optica, a rare disease similar to MS. Understanding how the antibodies bypass the protective blood-brain barrier could provide new approaches to treating the disease (Yukio Takeshita, MD, PhD, abstract 404.09, see attached summary).
• A protein involved in blood clotting might serve as an early detection method for MS before symptoms occur. Early detection of the disease could lead to more effective early treatments (Katerina Akassoglou, PhD, abstract 404.11, see attached summary).
• Low levels of a cholesterol protein correlate with the severity of a patient’s MS in both human patients and mouse models. The finding suggests the protein, known to protect against inflammation, may protect against developing MS, and possibly even aid in the regeneration of damaged neurons. This research opens the door to cholesterol drugs as a possible new avenue for MS treatment (Lidia Gardner, PhD, abstract 404.01, see attached summary).

Other recent findings discussed show that:

• A type of immune system cell has been found to directly target and damage nerve cell axons, a hallmark of MS. This may reveal a target for new therapies (Brian Sauer, PhD, presentation 404.06, see attached speaker summary).
• While no treatments to rebuild cells damaged by MS currently exist, scientists have found that when exosomes — tiny, naturally occurring “nanovesicles” — are produced by dendritic cells and applied to the brain, they can deliver a mixture of proteins and RNAs that promote regeneration of protective myelin sheaths and guard against MS symptoms (Richard Kraig, MD, PhD, presentation 812.02, see attached speaker summary).

“The findings shown today represent real promise for the millions suffering from MS,” said press conference moderator Jeffrey Rothstein of Johns Hopkins University and an expert in neurodegenerative diseases. “These studies are breakthroughs in understanding and treating a disease that remains uncured, difficult to diagnose, and for which it is very difficult to prevent progression.”

As little as 20 minutes of moderate exercise three times per week during pregnancy enhances the newborn child’s brain development, according to researchers at the University of Montreal and its affiliated CHU Sainte-Justine children’s hospital. This head-start could have an impact on the child’s entire life. “Our research indicates that exercise during pregnancy enhances the newborn child’s brain development,” explained Professor Dave Ellemberg, who led the study. “While animal studies have shown similar results, this is the first randomized controlled trial in humans to objectively measure the impact of exercise during pregnancy directly on the newborn’s brain. We hope these results will guide public health interventions and research on brain plasticity. Most of all, we are optimistic that this will encourage women to change their health habits, given that the simple act of exercising during pregnancy could make a difference for their child’s future.” Ellemberg and his colleagues Professor Daniel Curnier and PhD candidate Élise Labonté-LeMoyne presented their findings today at the Neuroscience 2013 congress in San Diego.

Not so long ago, obstetricians would tell women to take it easy and rest during their pregnancy. Recently, the tides have turned and it is now commonly accepted that inactivity is actually a health concern. “While being sedentary increases the risks of suffering complications during pregnancy, being active can ease post-partum recovery, make pregnancy more comfortable and reduce the risk of obesity in the children,” Curier explained. “Given that exercise has been demonstrated to be beneficial for the adult’s brain, we hypothesized that it could also be beneficial for the unborn child through the mother’s actions.”

To verify this, starting at the beginning of their second trimester, women were randomly assigned to an exercise group or a sedentary group. Women in the exercise group had to perform at least 20 minutes of cardiovascular exercise three times per week at a moderate intensity, which should lead to at least a slight shortness of breath. Women in the sedentary group did not exercise. The brain activity of the newborns was assessed between the ages of 8 to 12 days, by means of electroencephalography, which enables the recording of the electrical activity of the brain. “We used 124 soft electrodes placed on the infant’s head and waited for the child to fall asleep on his or her mother’s lap. We then measured auditory memory by means of the brain’s unconscious response to repeated and novel sounds,” Labonté-LeMoyne said. “Our results show that the babies born from the mothers who were physically active have a more mature cerebral activation, suggesting that their brains developed more rapidly.”

The researchers are now in the process of evaluating the children’s cognitive, motor and language development at age 1 to verify if these differences are maintained.

(Source: nouvelles.umontreal.ca)

New human and animal research released today demonstrates how experiences impact genes that influence behavior and health. Today’s studies, presented at Neuroscience 2013, the annual meeting of the Society for Neuroscience and the world’s largest source of emerging news about brain science and health, provide new insights into how experience might produce long-term brain changes in behaviors like drug addiction and memory formation.

The studies focus on an area of research called epigenetics, in which the environment and experiences can turn genes “on” or “off,” while keeping underlying DNA intact. These changes affect normal brain processes, such as development or memory, and abnormal brain processes, such as depression, drug dependence, and other psychiatric disease — and can pass down to subsequent generations.

Today’s new findings show that:

• Long-term heroin abusers show differences in small chemical modifications of their DNA and the histone proteins attached to it, compared to non-abusers. These differences could account for some of the changes in DNA/histone structures that develop during addiction, suggesting a potential biological difference driving long-term abuse versus overdose (Yasmin Hurd, abstract 257.2, see attached summary).
• Male rats exposed to cocaine may pass epigenetic changes on to their male offspring, thereby altering the next generation’s response to the drug. Researchers found that male offspring in particular responded much less to the drug’s influence (Matheiu Wimmer, PhD, abstract 449.19, see attached summary).
• Drug addiction can remodel mouse DNA and chromosomal material in predictable ways, leaving “signatures,” or signs of the remodeling, over time. A better understanding of these signatures could be used to diagnose drug addiction in humans (Eric Nestler, PhD, abstract 59.02, see attached summary).

Other recent findings discussed show that:

• Researchers have identified a potentially new genetic mechanism, called piRNA, underlying long-term memory. Molecules of piRNA were previously thought to be restricted to egg and sperm cells (Eric Kandel, MD, see attached summary).
• Epigenetic DNA remodeling is important for forming memories. Blocking this process causes memory deficits and stunts brain cell structure, suggesting a mechanism for some types of intellectual disability (Marcelo Wood, PhD, see attached summary).

"DNA may shape who we are, but we also shape our own DNA," said press conference moderator Schahram Akbarian, of the Icahn School of Medicine at Mount Sinai, an expert in epigenetics. "These findings show how experiences like learning or drug exposure change the way genes are expressed, and could be incredibly important in developing treatments for addiction and for understanding processes like memory."

(Source: eurekalert.org)

A pilot study by a multi-disciplinary team of investigators at Georgetown University suggests that a simple dot test could help doctors gauge the extent of dopamine loss in individuals with Parkinson’s disease (PD). Their study is being presented at Neuroscience 2013, the annual meeting of the Society for Neuroscience.

“It is very difficult now to assess the extent of dopamine loss — a hallmark of Parkinson’s disease — in people with the disease,” says lead author Katherine R. Gamble, a psychology PhD student working with two Georgetown psychologists, a psychiatrist and a neurologist. “Use of this test, called the Triplets Learning Task (TLT), may provide some help for physicians who treat people with Parkinson’s disease, but we still have much work to do to better understand its utility,” she adds.

Gamble works in the Cognitive Aging Laboratory, led by the study’s senior investigator, Darlene Howard, PhD, Davis Family Distinguished Professor in the department of psychology and member of the Georgetown Center for Brain Plasticity and Recovery.

The TLT tests implicit learning, a type of learning that occurs without awareness or intent, which relies on the caudate nucleus, an area of the brain affected by loss of dopamine.

The test is a sequential learning task that does not require complex motor skills, which tend to decline in people with PD. In the TLT, participants see four open circles, see two red dots appear, and are asked to respond when they see a green dot appear. Unbeknownst to them, the location of the first red dot predicts the location of the green target. Participants learn implicitly where the green target will appear, and they become faster and more accurate in their responses.

Previous studies have shown that the caudate region in the brain underlies implicit learning. In the study, PD participants implicitly learned the dot pattern with training, but a loss of dopamine appears to negatively impact that learning compared to healthy older adults.

“Their performance began to decline toward the end of training, suggesting that people with Parkinson’s disease lack the neural resources in the caudate, such as dopamine, to complete the learning task,” says Gamble.

In this study of 27 people with PD, the research team is now testing how implicit learning may differ by different PD stages and drug doses.

“This work is important in that it may be a non-invasive way to evaluate the level of dopamine deficiency in PD patients, and which may lead to future ways to improve clinical treatment of PD patients,” explains Steven E. Lo, MD, associate professor of neurology at Georgetown University Medical Center, and a co-author of the study.

They hope the TLT may one day be a tool to help determine levels of dopamine loss in PD.

(Source: explore.georgetown.edu)