Posts tagged neuroscience
Articles and news from the latest research reports.
In Alzheimer’s Disease, Maintaining Connection and ‘Saving Face’
I’ve decided that all older men with gray beards must look alike, because each week I am mistaken for someone else. But, if I were to shave my beard - which I have worn for over 40 years - I believe that my friends and colleagues would fail to recognize me. I would be a different person to them because of this small, physical change.
If such a small change affects the way people see me, then the larger mental changes that Alzheimer’s patients experience must truly and deeply change the way their loved ones see them. Dr. Daniel Potts, a neurologist at the University of Alabama, has begun studying the concept of “saving face” and preserving the “person” in people with dementia.
Dr. Potts’ father, Lester Potts, became an acclaimed watercolor artist after his Alzheimer’s diagnosis. He had lost his verbal abilities but could express his feelings through his art. This bolstered his retention of self-worth and dignity. His paintbrush let him bypass the part of his brain that Alzheimer’s blocked, and communicate in a new way.
But before we find out more about art and Alzheimer’s patients, let’s go back to the “face” part of saving face for just a moment.
(Source: The Atlantic)
Re-learning words lost to dementia
A simple word-training program has been found to restore key words in people with a type of dementia that attacks language and our memory for words.
This ability to relearn vocabulary indicates that even in brains affected by dementia, some recovery of function is possible.
The study, led by Ms Sharon Savage at NeuRA (Neuroscience Research Australia), utilised a simple computer training-program that paired images of household objects such as food, appliances, utensils, tools and clothing, with their names.
“People with this type of dementia lose semantic memory, the memory system we use to store and remember words and their meanings,” says Ms Savage.
“Even the simplest words around the house can be difficult to recall. For example, a person with this type of dementia usually knows what a kettle does, but they may not know what to call it and may not recognize the word ‘kettle’ when they hear it,” she says.
Ms Savage found that after just 3 weeks of training for 30–60 min each day, patients’ ability to recall the name of the items improved, even for patients with more advanced forms of the dementia.
“Semantic dementia is a younger-onset dementia and because sufferers lose everyday words life can be very frustrating for them and their families. By relearning some of these everyday words, day to day conversations around the house may become less frustrating, improving patient well-being,” Ms Savage concludes.
Alcohol Drinking Behavior Reduced By Inhibiting Brain Protein in Rodents
Decreasing the level of a key brain protein led to significantly less drinking and alcohol-seeking behavior in rats and mice that had been trained to drink, according to a study by researchers at the Ernest Gallo Clinic and Research Center at UCSF.
The scientists identified the protein, known as H-Ras, as a promising target for development of new medications to treat alcohol abuse disorders in humans.
The study, which was published on Nov. 7 in the Journal of Neuroscience, was recommended as being of special significance in its field by the Faculty of 1000, an online service that identifies great peer-reviewed biomedical research.
The researchers, led by Gallo investigator Dorit Ron, PhD, first demonstrated that alcohol intake significantly increased H-Ras activity in the animals’ nucleus accumbens, a brain region that in both rodents and humans is part of the reward system that affects craving for alcohol and other addictive substances.
They then showed that suppressing H-Ras levels in the nucleus accumbens with a targeted virus reduced alcohol consumption among mice that had been trained to seek out and drink alcohol in an animal model of binge drinking.
The researchers then administered FTI-276, an experimental compound that has been shown to inhibit H-Ras production, to binge-drinking rats. They observed a significant reduction in alcohol consumption after the compound was given.
The scientists also found that H-Ras inhibition reduced alcohol-seeking behavior among rats that had been trained to receive a drink of alcohol when they pressed a lever. When alcohol was withheld, rats that had received FTI-276 discontinued pressing the lever significantly sooner than rats that did not receive the compound.
Importantly, the rodents’ consumption of water, sugar solution, saccharine solution and quinine was not reduced when H-Ras was inhibited, indicating that H-Ras activity is specific to alcohol.
Scientists have learned a lot about pain, but this has not led to the discovery of many new medications to help the millions of people whose lives are affected by chronic pain.
In an effort to improve pain management, Frank Porreca, PhD, and his research group from the Department of Pharmacology at the University of Arizona College of Medicine – Tucson have been exploring new preclinical measures that may better reflect features of the human experience of pain and that can be used to find new therapies.
Relief of pain is rewarding, according to Dr. Porreca and his colleagues. They have demonstrated that treatments that relieve the unpleasant feeling of pain also activate reward circuits and reinforce behaviors that result in relief of pain. Their study, “Pain relief produces negative reinforcement through activation of mesolimbic reward/valuation circuitry,” is reported in the Nov. 26 Early Edition issue of the Proceedings of the National Academy of Sciences.
“Determining how we feel, including knowing if we are in pain, depends on a brain neural representation of information that is gathered by a multitude of sensors that monitor the body and its tissues for local temperature, blood flow, blood pressure, heart rate, pH, carbon dioxide level and other states,” says Dr. Porreca. “These ‘interoceptors’ constantly evaluate and report the state of the body to the brain, generating specific conscious sensations that tell us that we are hungry, thirsty or cold, or that something is wrong. Nociceptors are a special class of interoceptors that produce sensations of pain. They ‘sound the alarm’ to tell us that our tissues have been – or soon may be – damaged.”
Thirst, hunger, itch, cold, heat, pain and other states of imbalance are unpleasant feelings that demand a behavioral response to correct the problem, Dr. Porreca says. If you feel cold, you want to get warm; if you are thirsty, you want to drink; if you are in pain, you want relief.
What motivates an organism to respond to these feelings? Things that are essential to the life of an organism or the survival of the species, such as food or drink, are rewarding. Rewards activate neural circuits in the brain and produce pleasant and positive feelings that reinforce behaviors that increase our ability to survive, notes Dr. Porreca.
The UA researchers have demonstrated that treatments that relieve the unpleasant feeling of pain also result in activation of these same reward circuits and reinforce behaviors that result in relief of pain. The novel demonstration of pain relief as a reward provides an entirely new way to discover medicines for patients.
“The activation of the reward circuit by pain relief provides an output measure for assessment of the potential effectiveness of novel molecular targets,” Dr. Porreca explains. “The activation of these ancient and evolutionarily conserved circuits by pain relief can serve as a basis for translation of treatments that will likely be effective in humans.”
Seeing the world through the eyes of an Orangutan
Dr Neil Mennie, from The University of Nottingham Malaysia Campus (UNMC), has received funding from Ministry of Science and Technology and Innovation, Malaysia (MOSTI) to study the eye movements of Tsunami — a seven year old orangutan at The National Zoo of Malaysia (Zoo Negara). Not only will Dr Mennie’s research address vital questions about the visual cognition of humans and apes in natural tasks, it will also provide valuable enrichment for the juvenile captive-born orangutan.
Dr Mennie said: “Orangutans are particularly interesting because to survive in the treetops they must be very spatially aware of their surroundings. I hope to investigate their ability to search for food and to compare their progress with humans in 3D search and foraging tasks.
Dr Mennie, who is from the Cognitive and Sensory Systems Research Group in the School of Psychology at UNMC, is interested in how humans and apes use their brains to learn and make predictions about our surroundings. With the help of Tsunami’s keeper, Mohd Sharullizam Ramli, and the special eye tracking equipment that is worn over her head and shoulders, Dr Mennie has spent the last year recording Tsunami’s eye and body movements during the performance of complex actions such as locomotion, foraging for food and manipulation of small objects.
A sonar vision system for the congenitally blind
A “sonar vision” system that enables people who are blind from birth to perceive the shape of a face, a house or even words and letters, is being developed by a team at the Hebrew University of Jerusalem. Using this device, the researchers have shown that, in people that are blind from birth, the areas of the cerebral cortex normally devoted to reading become activated in response to stimulation. The results of this study, conducted in conjunction with researchers at the ICM Brain and Bone Marrow Institute Research Center (Inserm/UPMC/AP-HP) and NeuroSpin (CEA-Inserm), were published in Neuron on November 8.
Results: At the moment that someone is suffering a stroke, the immediate concern is getting them stabilized. Once the initial attack has passed, additional treatment and preventive measures can be implemented. Understanding what’s happening during the actual event, and in the subsequent hours and days, will help improve the effectiveness of the post-attack treatment plan, and also help identify methods of neuroprotection—that is, administer treatments to protect against a stroke in advance for potentially at-risk individuals. Computational biology researchers at Pacific Northwest National Laboratory developed a model for predicting what’s happening during a stroke, how the process evolves over time, the potential outcomes, and the effects of different treatment options.
The work was featured in the journal PLOS Computational Biology
Why It Matters: The ability to examine strokes and other biological processes, through the use of computer simulations rather than after the fact on actual organisms, may significantly accelerate how quickly discoveries can be made in fighting diseases. The ability to model and simulate different treatments prior to administering them to a patient can help predict with more certainty which therapeutic approaches may be the most effective.
"This is the first step in being able to suggest {to health care providers} that if you do X and Y, you’d get a much bigger effect than what you’re currently doing,” said Dr. Jason McDermott, a PNNL computational biologist and lead author on the paper.
Methods: The team developed novel mathematical approaches for extending existing methods of determining causal relationships between genes that are driving biological processes. They implemented ordinary differential equations—a process for describing how things change over time—to improve their ability to infer what these gene relationships might look like and to allow more dynamic simulation of these biological processes over time.
What’s Next: The team is looking at improving the model to simulate events that are happening during a biological process for which there isn’t pre-existing data. Additionally, they plan to test the effect of adding drugs to a treatment plan and also will be looking at micro RNA molecules that currently aren’t included in the model.
Brief exercise immediately enhances memory
A short burst of moderate exercise enhances the consolidation of memories in both healthy older adults and those with mild cognitive impairment, scientists with UC Irvine’s Center for the Neurobiology of Learning & Memory have discovered.
Most research has focused on the benefits of a long-term exercise program on overall health and cognitive function with age. But the UCI work is the first to examine the immediate effects of a brief bout of exercise on memory.
In their study, post-doctoral researcher Sabrina Segal and neurobiologists Carl Cotman and Lawrence Cahill had people 50 to 85 years old with and without memory deficits view pleasant images – such as photos of nature and animals – and then exercise on a stationary bicycle for six minutes at 70 percent of their maximum capacity immediately afterward.
One hour later, the participants were given a surprise recall test on the previously viewed images. Results showed a striking enhancement of memory by exercise in both the healthy and cognitively impaired adults, compared with subjects who did not ride the bike.
“We found that a single, short instance of moderately intense exercise particularly improved memory in individuals with memory deficits,” Segal said. “Because of its implications and the need to better understand the mechanism by which exercise may enhance memory, we’re following up this study with an investigation of potential underlying biological factors.”
She believes the improved memory may be related to the exercise-induced release of norepinephrine, a chemical messenger in the brain known to play a strong role in memory modulation. This hypothesis is based on previous work demonstrating that increasing norepinephrine through pharmacological manipulation sharpens memory and that blocking norepinephrine impairs memory.
In the more recent research, Segal and her colleagues discovered that levels of salivary alpha amylase, a biomarker that reflects norepinephrine activity in the brain, significantly increased in participants after exercise. This correlation was especially strong in people with memory impairment.
“The current findings offer a natural and relatively safe alternative to pharmacological interventions for memory enhancement in healthy older individuals as well as those who suffer from cognitive deficits,” Segal noted. “With a growing population of the aged, the need for improvement of quality of life and prevention of mental decline is more important than ever before.”
Study results appear in the November issue (Volume 32, Number 4) of the Journal of Alzheimer’s Disease.
(Source: news.uci.edu)
Researchers Study Cry Acoustics of Infants to Determine Risk for Autism
Autism is a poorly understood family of related conditions. People with autism generally lack normal social interaction skills and engage in a variety of unusual and often characteristic behaviors, such as repetitive movements. While there is no specific medical treatment for autism, some success has been shown with early behavioral intervention.
Understanding the importance of early diagnosis, researchers at Women & Infants’Brown Center for the Study of Children at Riskin collaboration with researchers at University of Pittsburgh have been studying the cry acoustics of six-month-old infants. Their research has recently been published in Autism Research.
“Because we can measure various aspects of babies’ cries from the earliest days of life, it may be possible to use this technique to identify risk for neurological problems such as autism long before we can detect behavioral differences,” said Stephen J. Sheinkopf, PhD, lead researcher, psychologist at the Brown Center for the Study of Children at Risk, and assistant professor (research) in the Department of Psychiatry and Human Behavior at The Warren Alpert Medical School of Brown University.
The study examined ways in which infants at risk for autism produced cries as compared to the cries of low-risk infants. Recordings of babies’ cries were excerpted from vocal and video recordings of six-month-old infants at risk for autism spectrum disorder (ASD) and those with low risk. Infants were considered to be at risk if they had an older sibling with a confirmed ASD diagnosis.
Cries were categorized as either pain related or non-pain related based on observations of the videotapes. At-risk infants produced pain related cries with higher and more variable fundamental frequency (commonly referred to as “pitch”) as compared to low-risk infants. A small number of the at-risk infants were later diagnosed with an ASD at 36 months of age. The cries for these babies had among the highest fundamental frequency values and also differed in other acoustic characteristics.
“These findings demonstrate the potential of this approach for babies as young as six months of age,” said Dr. Sheinkopf.
(Photo: Thinkstock Source: Getty Images)
Researchers find reading uses the same brain regions regardless of language
A team of French and Taiwanese researchers has found evidence to indicate that people use the same regions of the brain when reading, regardless of which language is being read. In their paper published in the Proceedings of the National Academy of Sciences, they describe how fMRI brain scans made while people were reading revealed that there are very few differences in how the brain works as reading occurs.
The researchers note that previous research has suggested that different neural networks might be involved when people read text written in very different types of languages. French, for example, is an alphabetic language, whereas Chinese is logographic. Those of Roman origin are based on abstract concepts while Chinese characters are based on realistic depictions of handwriting strokes.
To learn more, the researchers ran fMRI scans on volunteers reading either Chinese or French material as their native language. The material presented was shown in various forms, e.g. normal, static, backwards or distorted. The researchers also employed priming, which is where words are flashed on a screen for such a short period of time as to be unknown to the reader. Priming has been found to influence the rate at which readers recognize words that are shown thereafter for a normal duration of time. The material written in French was presented as cursive rather than block printed letters.
In analyzing the results, the researchers found the differences in brain activity between the two groups as they read to be minimal. Those differences that were found, centered around a slight increase in the brain regions associated with processing the physical movements that had occurred in creating the characters, which in the brain is recognized as motor skills.
The researchers suggest that their results indicate that because reading is a relatively new process for the human brain, it likely evolved using previously existing neural network circuitry, which would explain why it appears the brain works in roughly the same way when reading, regardless of language.