Posts tagged neuroscience

Posts tagged neuroscience
The brain is a notoriously difficult organ to treat, but Johns Hopkins researchers report they are one step closer to having a drug-delivery system flexible enough to overcome some key challenges posed by brain cancer and perhaps other maladies affecting that organ.
In a report published online on August 29 in Science Translational Medicine, the Johns Hopkins team says its bioengineers have designed nanoparticles that can safely and predictably infiltrate deep into the brain when tested in rodent and human tissue.
“We are pleased to have found a way to prevent drug-embedded particles from sticking to their surroundings so that they can spread once they are in the brain,” says Justin Hanes, Ph.D., Lewis J. Ort Professor of Ophthalmology, with secondary appointments in chemical and biomolecular engineering, biomedical engineering, oncology, neurological surgery and environmental health sciences, and director of the Johns Hopkins Center for Nanomedicine.
Mr. Abicca, a 17-year-old from San Diego, is essentially wearing a robot. His bionic suit consists of a pair of mechanical braces wrapped around his legs and electric muscles that do much of the work of walking. It is controlled by a computer on his back and a pair of crutches held in his arms that look like futuristic ski poles.
Since an accident involving earth-moving equipment three years ago that damaged his spinal cord, Mr. Abicca has been unable to walk on his own. The suit, made by a company called Ekso Bionics, is an effort to change that.
In a recent study, investigators at Boston University Schools of Medicine (BUSM) and Public Health (BUSPH) identified a gene linking age-related cataracts and Alzheimer’s disease. The findings, published online in PLoS ONE, contribute to the growing body of evidence showing that these two diseases, both associated with increasing age, may share common etiologic factors.
“Doctor” or “Darling”: The Subtle Differences of Speech
Human speech comes in countless varieties: When people talk to close friends or partners, they talk differently than when they address a physician. These differences in speech are quite subtle and hard to pinpoint. In a recent special issue of the journal Frontiers in Human Neuroscience, Johanna Derix, Dr. Tonio Ball, and their colleagues from the Bernstein Center and the University Medical Center in Freiburg report that they were able to tell from brain signals who a person was talking to. This discovery could contribute to the further development of speech synthesizers for patients with severe paralysis.
In contrast to the experimental research common in human neuroscience, the scientists studied natural, non-experimental behavior. Patients who, for medical reasons, had electrodes implanted underneath their skull allowed their brain activity to be recorded during daily life in the hospital. The Freiburg researchers compared data recorded during natural conversations that the patients had with their physicians and their life partners. They found pronounced differences in the anterior temporal lobe, a brain area well known for its significance in social interaction. Several components of neural signals that are detectable on the brain surface can convey such information.
“This study is only the first step towards elucidating the neural basis of human everyday behavior,” explains the neuroscientist and physician Tonio Ball. “Such investigations will become especially important in developing new neurotechnological treatment options for patients with impaired motor and language functions that work in real life situations.” The restoration of speech production becomes necessary in some forms of neurological diseases and chronic paralysis. A computer could synthesize speech for patients suffering from such conditions by using their brain signals. Information on who the patient is addressing could help the device to select the degree of formality – and to prevent it from calling the doctor “darling.”
The cellular cause of birth defects like cleft palates, missing teeth and problems with fingers and toes has been a tricky puzzle for scientists.
Professor Emily Bates and her biochemistry students at Brigham Young University studied an ion channel that regulates the electrical charge of a cell. In a new study published by the journal Development, they show that blocking this channel disrupts the work of a protein that is supposed to carry marching orders to the nucleus.
Without those instructions, cells don’t become what they were supposed to become – be that part of a palate, a tooth or a finger. Though there are various disorders that lead to birth defects, this newly discovered mechanism may be what some syndromes have in common.
Bates and her graduate student, Giri Dahal, now want to apply the findings toward the prevention of birth defects – particularly those caused by fetal alcohol syndrome and fetal alcohol spectrum disorder.
"What we think might be the case is that this is the target for a few similar disorders," Bates said. "The big thing that we have right now is that this ion channel is required for protein signaling, which means that developmental signaling pathways can sense the charge of a cell. And that’s exciting for a lot of different reasons."
For example, the new study might also have implications for the battle against cancer. With cancer, the problem is that cells are receiving a bad set of instructions that tells them to multiply and spread. If they can devise a way to block the ion channel, it may stop those cancerous instructions from getting through.
"This protein signaling pathway is the same one that tells cancer cells to metastasize," Bates said. "We’re planning to test a therapy to specifically block this channel in just the cells that we want to stop."
How non-verbal cues can predict a person’s (and a robot’s) trustworthiness
People face this predicament all the time—can you determine a person’s character in a single interaction? Can you judge whether someone you just met can be trusted when you have only a few minutes together? And if you can, how do you do it? Using a robot named Nexi, Northeastern University psychology professor David DeSteno and collaborators Cynthia Breazeal from MIT’s Media Lab and Robert Frank and David Pizarro from Cornell University have figured out the answer. The findings were recently published in the journal Psychological Science, a journal of the Association for Psychological Science.
It’s What You’re Not Saying…
In the absence of reliable information about a person’s reputation, nonverbal cues can offer a look into a person’s likely actions. This concept has been known for years, but the cues that convey trustworthiness or untrustworthiness have remained a mystery. Collecting data from face-to-face conversations with research participants where money was on the line, DeSteno and his team realized that it’s not one single non-verbal movement or cue that determines a person’s trustworthiness, but rather sets of cues. When participants expressed these cues, they cheated their partners more, and, at a gut level, their partners expected it. “Scientists haven’t been able to unlock the cues to trust because they’ve been going about it the wrong way,” DeSteno said. “There’s no one golden-cue. Context and coordination of movements is what matters.”
Robots Have Feelings, Too
People are fidgety – they’re moving all the time. So how could the team truly zero-in on the cues that mattered? This is where Nexi comes in. Nexi is a humanoid social robot that afforded the team an important benefit – they could control all its movements perfectly. In a second experiment, the team had research participants converse with Nexi for 10 minutes, much like they did with another person in the first experiment. While conversing with the participants, Nexi — operated remotely by researchers — either expressed cues that were considered less than trustworthy or expressed similar, but non-trust-related cues. Confirming their theory, the team found that participants exposed to Nexi’s untrustworthy cues intuited that Nexi was likely to cheat them and adjusted their financial decisions accordingly. “Certain nonverbal gestures trigger emotional reactions we’re not consciously aware of, and these reactions are enormously important for understanding how interpersonal relationships develop,” said Frank. “The fact that a robot can trigger the same reactions confirms the mechanistic nature of many of the forces that influence human interaction.”
Real-Life Application
This discovery has led the research team to not only answer enduring questions about if and how people are able to assess the trustworthiness of an unknown person, but also to show the human mind’s willingness to ascribe trust-related intentions to technological entities based on the same movements. “This is a very exciting result that showcases how social robots can be used to gain important insights about human behavior,” said Cynthia Breazeal of MIT’s Media Lab. “This also has fascinating implications for the design of future robots that interact and work alongside people as partners.” Accordingly, these findings hold important insights not only for security and financial endeavors and for the evolving design of robots and computer-based agents. The subconscious mind is ready to see these entities as social beings.
The world continues to be a noisy place, and Purdue University researchers have found that all that background chatter causes the ears of those with hearing impairments to work differently.
"When immersed in the noise, the neurons of the inner ear must work harder because they are spread too thin," said Kenneth S. Henry, a postdoctoral researcher in Purdue’s Department of Speech, Language and Hearing Sciences. "It’s comparable to turning on a dozen television screens and asking someone to focus on one program. The result can be fuzzy because these neurons get distracted by other information."
The findings, by Henry and Michael G. Heinz, an associate professor of speech, language and hearing sciences, are published as a Brief Communication in Nature Neuroscience. The work was funded by the National Institutes of Health and the National Institute on Deafness and Other Communication Disorders.
Non-smokers who live with or spend time with smokers are damaging their memory, according to new research from Northumbria University.
The findings, published in the latest online edition of the journal Addiction is the first study to explore the relationship between exposure to other people’s smoke and everyday memory problems.
Dr Tom Heffernan and Dr Terence O’Neil, both researchers at the Collaboration for Drug and Alcohol Research Group at Northumbria University, compared a group of current smokers with two groups of non-smokers – those who were regularly exposed to second-hand smoke and those who were not.
Those exposed to second-hand smoke either lived with smokers or spent time with smokers, for example in a designated “smoking area,” and reported being exposed to second-hand smoke for an average of 25 hours a week for an average of four and a half years.
The three groups were tested on time-based memory (remembering to carry out an activity after some time) and event-based memory (which refers to memory for future intentions and activities).
Researchers found that the non-smokers who had been exposed to second-hand smoke forgot almost 20% more in the memory tests than those non-smokers not exposed. However, both groups out-performed the current smokers who forgot 30% more than those who were not exposed to second-hand smoking.
Dr Heffernan said: “According to recent reports by the World Health Organisation, exposure to second-hand smoke can have serious consequences on the health of people who have never smoked themselves, but who are exposed to other people’s tobacco smoke.
“Our findings suggest that the deficits associated with second-hand smoke exposure extend to everyday cognitive function. We hope our work will stimulate further research in the field in order to gain a better understanding of the links between exposure to second-hand smoke, health problems and everyday cognitive function.”
(Source: northumbria.ac.uk)
Have you ever wondered why some people find it so much easier to stop smoking than others?
New research shows that vulnerability to smoking addiction is shaped by our genes. A study from the Montreal Neurological Institute and Hospital - The Neuro, McGill University shows that people with genetically fast nicotine metabolism have a significantly greater brain response to smoking cues than those with slow nicotine metabolism. Previous research shows that greater reactivity to smoking cues predicts decreased success at smoking cessation and that environmental cues promote increased nicotine intake in animals and humans. This new finding that nicotine metabolism rates affect the brain’s response to smoking may lead the way for tailoring smoking cessation programs based on individual genetics.
Researchers from the University of Utah have gained new insight into the regulation of adult nerve cell generation in the hypothalamus, the part of the brain that regulates many aspects of behavior, mood, and metabolism. In the Sept. 10, 2012, issue of Developmental Cell they report that a cell-to-cell communication network known as the Wnt signaling pathway plays an important role in both the production and specialization of nerve cell precursors in the hypothalamus.
The hypothalamus is a highly complex region of the brain that controls hunger, thirst, fatigue, body temperature, and sleep. It also links the central nervous system to the body system that regulates hormone levels. Recent studies have shown that the hypothalamus is one of the parts of the brain in which neurogenesis, the birth of new nerve cells, continues throughout adulthood.
“In our earlier work, we discovered that Wnt signaling was required for neurogenesis in the embryonic zebrafish hypothalamus,” says Richard Dorsky, Ph.D., associate professor of neurobiology and anatomy at the University of Utah School of Medicine and senior author on the study. “We also found that, in zebrafish, both Wnt signaling and hypothalamic neurogenesis continue into adulthood. The goal of this study was to define specific roles for Wnt signaling in neurogenesis.”
The Wnt signaling pathway is a network of proteins that transmits signals from the cell surface to DNA in the cell nucleus to regulate gene expression, and it is known to play a critical role in cell-to-cell communication in both embryos and adults. In this study, Dorsky and his colleagues demonstrated that in zebrafish embryos Wnt signaling is present in progenitor cells that are actively multiplying in the hypothalamus. Progenitor cells have the potential to divide and differentiate into a variety of specialized cell types. Dorsky and his colleagues also found that Wnt signaling continues to be required for hypothalamic neurogenesis throughout life.
Neural progenitor cells arise from neural stem cells, and retain the capacity to develop into more specialized types of nerve cells. After the embryo is formed, some neural stem cells lie dormant in the brain and spinal cord until they are activated to serve as a repair system. When tissue damage or death occurs, chemical substances trigger these neural stem cells to make neural progenitor cells that assist in tissue recovery. Recent research suggests that other neural progenitor cells continue to make new nerve cells in the uninjured brain and contribute to the plasticity of the brain in response to changes in the environment.
“From a functional standpoint, it is not yet clear why the ability to continuously produce hypothalamic nerve cells is important in adult zebrafish,” says Dorsky. “However, in adult mice, hypothalamic neurogenesis seems to be significant in the regulation of feeding behaviors due to environmental changes.”
Dorsky and his colleagues discovered that the role of the Wnt signaling pathway differs between embryos and adults. In zebrafish embryos, activation of Wnt signaling is required for proliferation of progenitor cells contributing to growth of brain structures. However, at later stages of development including adulthood, Wnt signaling must be active for neural progenitor cells to commit to becoming nerve cells, but then must be inhibited for these cells to complete the differentiation process. Significantly, Dorsky and his colleagues also found that mice displayed a similar pattern of Wnt activity.
“Compared to other regions of the brain, the hypothalamus is relatively unstudied as a model of post-embryonic neurogenesis,” says Dorsky. “Our research represents a significant contribution to the field because it establishes the vertebrate hypothalamus as a model of Wnt-regulated neural progenitor differentiation that can be used to shed light on the plasticity of the adult brain.”
(Source: newswise.com)