Posts tagged neuroscience
Articles and news from the latest research reports.
Implications for treating muscular dystrophy and other muscle wasting diseases
Working with mice, Johns Hopkins researchers have solved a key part of a muscle regeneration mystery plaguing scientists for years, adding strong support to the theory that muscle mass can be built without a complete, fully functional supply of muscle stem cells.
"This is good news for those with muscular dystrophy and other muscle wasting disorders that involve diminished stem cell function," says Se-Jin Lee, M.D., Ph.D., lead author of a report on the research in the August issue of the Proceedings of the National Academy of Sciences and professor of molecular biology and genetics at the Johns Hopkins University School of Medicine.
Why do teenagers seem so much more impulsive, so much less self-aware than grown-ups? Cognitive neuroscientist Sarah-Jayne Blakemore compares the prefrontal cortex in adolescents to that of adults, to show us how typically “teenage” behavior is caused by the growing and developing brain.
Sarah-Jayne Blakemore studies the social brain — the network of brain regions involved in understanding other people — and how it develops in adolescents.
Almost everyone knows the feeling: you see a delicious piece of chocolate cake on the table, but as you grab your fork, you think twice. The cake is too fattening and unhealthy, you tell yourself. Maybe you should skip dessert.
But the cake still beckons.
In order to make the healthy choice, we often have to engage in this kind of internal struggle. Now, scientists at the California Institute of Technology (Caltech) have identified the neural processes at work during such self-regulation—and what determines whether you eat the cake.
"We seem to have independent systems capable of guiding our decisions, and in situations like this one, these systems may compete for control of what we do," says Cendri Hutcherson, a Caltech postdoctoral scholar who is the lead author on a new paper about these competing brain systems, which will be published in the September 26 issue of The Journal of Neuroscience.
A robot developed by Computer Science Ph.D. candidate Justin Hart GRD ’13 at the Social Robotics Lab may pass a landmark test by recognizing itself changing in a mirror.
Self-awareness, the ability to recognize oneself as distinct from one’s surroundings, is a mark of higher-level cognitive skills. This test was first developed to test the presence of self-awareness in animals, and requires the subject to recognize a change in its appearance by looking at its reflection.
In the mirror test, developed by Gordon Gallup in 1970, a mirror is placed in an animal’s enclosure, allowing the animal to acclimatize to it. At first, the animal will behave socially with the mirror, assuming its reflection to be another animal, but eventually most animals recognize the image to be their own reflections. After this, researchers remove the mirror, sedate the animal and place an ink dot on its frontal region, and then replace the mirror. If the animal inspects the ink dot on itself, it is said to have self-awareness, because it recognized the change in its physical appearance.
Only a few species of animals, including chimpanzees, bottlenose dolphins, magpies and elephants, have passed the test.
An artificially intelligent virtual gamer created by computer scientists at The University of Texas at Austin has won the BotPrize by convincing a panel of judges that it was more human-like than half the humans it competed against.
Melatonin and exercise work against Alzheimer’s in mice
Different anti-aging treatments work together and add years of life
The combination of two neuroprotective therapies, voluntary physical exercise, and the daily intake of melatonin has been shown to have a synergistic effect against brain deterioration in rodents with three different mutations of Alzheimer’s disease.
A study carried out by a group of researchers from the Barcelona Biomedical Research Institute (IIBB), in collaboration with the University of Granada and the Autonomous University of Barcelona, shows the combined effect of neuroprotective therapies against Alzheimer’s in mice.
Daily voluntary exercise and daily intake of melatonin, both of which are known for the effects they have in regulating circadian rhythm, show a synergistic effect against brain deterioration in the 3xTg-AD mouse, which has three mutations of Alzheimer’s disease.
"For years we have known that the combination of different anti-aging therapies such as physical exercise, a Mediterranean diet, and not smoking adds years to one’s life," Coral Sanfeliu, from the IIBB, explains to SINC. "Now it seems that melatonin, the sleep hormone, also has important anti-aging effects".
The experts analysed the combined effect of sport and melatonin in 3xTg-AD mice which were experiencing an initial phase of Alzheimer’s and presented learning difficulties and changes in behaviour such as anxiety and apathy.
The mice were divided into one control group and three other groups which would undergo different treatments: exercise –unrestricted use of a running wheel–, melatonin –a dose equivalent to 10 mg per kg of body weight–, and a combination of melatonin and voluntary physical exercise. In addition, a reference group of mice were included which presented no mutations of the disease.
"After six months, the state of the mice undergoing treatment was closer to that of the mice with no mutations than to their own initial pathological state. From this we can say that the disease has significantly regressed," Sanfeliu states.
The results, which were published in the journal Neurobiology of Aging, show a general improvement in behaviour, learning, and memory with the three treatments.
These procedures also protected the brain tissue from oxidative stress and provided good levels of protection from excesses of amyloid beta peptide and hyperphosphorylated TAU protein caused by the mutations. In the case of the mitochondria, the combined effect resulted in an increase in the analysed indicators of improved performance which were not observed independently.
(Source: eurekalert.org)
Cross-Category Adaptation: Objects Produce Gender Adaptation in the Perception of Faces
Adaptation aftereffects have been found for low-level visual features such as colour, motion and shape perception, as well as higher-level features such as gender, race and identity in domains such as faces and biological motion. It is not yet clear if adaptation effects in humans extend beyond this set of higher order features. The aim of this study was to investigate whether objects highly associated with one gender, e.g. high heels for females or electric shavers for males can modulate gender perception of a face. In two separate experiments, we adapted subjects to a series of objects highly associated with one gender and subsequently asked participants to judge the gender of an ambiguous face. Results showed that participants are more likely to perceive an ambiguous face as male after being exposed to objects highly associated to females and vice versa. A gender adaptation aftereffect was obtained despite the adaptor and test stimuli being from different global categories (objects and faces respectively). These findings show that our perception of gender from faces is highly affected by our environment and recent experience. This suggests two possible mechanisms: (a) that perception of the gender associated with an object shares at least some brain areas with those responsible for gender perception of faces and (b) adaptation to gender, which is a high-level concept, can modulate brain areas that are involved in facial gender perception through top-down processes.
Caltech study shows that the distance at which facial photos are taken influences perception
Previous studies have examined how our social judgments of pictures of people are influenced by factors such as whether the person is smiling or frowning, but until now one factor has never been investigated: the distance between the photographer and the subject. According to a new study by researchers at the California Institute of Technology (Caltech), this turns out to make a difference—close-up photo subjects, the study found, are judged to look less trustworthy, less competent, and less attractive.
The new finding is described in this week’s issue of the open-access journal PLoS One.
'Scar free healing' in mice may give clues to human skin repair
Mice with brittle skin, which tears off in order to escape predators, may offer clues to healing wounds without scarring, according to US researchers.
Some African spiny mice lost up to 60% of the skin from their backs, says the study published in the journal Nature. Unlike wounds in other mammals, the skin then rapidly healed and regrew hairs rather than forming a scar. Scientists want to figure out how the healing takes place and if it could apply to people.
Salamanders, some of which can regrow entire limbs, are famed for their regenerative abilities. It has made them the focus of many researchers hoping to figure out how to produce the same effect in people. Mammals, however, have very limited ability to regrow lost organs. Normally a scar forms to seal the wound. “This study shows that mammals as a group may in fact have higher regenerative abilities then they are given credit for,” said Dr Ashley Seifert from the University of Florida.
(Source: BBC)
Male DNA in women’s brains could protect against Alzheimer’s
Researchers found that up to two thirds of women carry male DNA in their brain, which was most likely passed on to them while pregnant with sons.
The exact medical consequences of the transfer from foetus to mother remains unclear but a study showed it was less common in women who suffered from Alzheimer’s, suggesting that it could offer protection against the condition.
Previous studies insicate that similar processes of DNA transfer could raise the risk of some cancers, such as breast cancer, and lower the risk of others including cancer of the colon.
The new study of brain tissue taken from 59 women who died aged 32 to 101 found male DNA in 63 per cent of specimens.
The findings, published in the Public Library of Science ONE journal, also showed that the male DNA was less common in the parts of the brain most severely damaged by Alzheimer’s.
But the researchers, from the Fred Hutchinson Cancer Research Centre in Seattle, emphsaised that the small scale of the study and the lack of data on the women’s pregnancy history meant the evidence was not conclusive.
Dr William Chan, who led the project, said: “Currently, the biological significance of harbouring male DNA and male cells in the human brain requires further investigation.”