Addiction disorders of various kinds are a major health and social problem, and our knowledge of how the brain's reward system functions needs to be enhanced. Uppsala researchers now shows an unexpected effect of the signal substance glutamate on the midbrain in mice. The study is published in the Web edition of Proceedings of the National Academy of Sciences, PNAS.
"We have found that a certain part of the brain's reward system requires not only the signal substance dopamine, as was previously thought, but also glutamate" says Ĺsa Mackenzie, who directed the study at the Department of Neuroscience, Uppsala University.
Among other things, the dopamine nerve cells in the midbrain are important for the brain's control of willed movements and for the brain's "reward system." The latter in turn is important for providing us with a feeling of pleasure and happiness, for example, when we have eaten, worked out, or been affirmed. The feeling itself is mediated by dopamine released from the midbrain's dopamine-producing nerve cells to the brain's limbic system.
Health & Wellness
If you paint, dance or play a musical instrument -- or just enjoy going to the theatre or to concerts -- it's likely that you feel healthier and are less depressed than people who don't, a survey of nearly 50,000 individuals from all socio-economic backgrounds from a county in mid-Norway shows.
The findings are drawn from the latest round of studies conducted for the Norwegian University of Science and Technology's (NTNU) Nord-Trøndelag Health Study, or HUNT, which used questionnaires, interviews, clinical examinations and the collection of blood and urine samples to assemble detailed health profiles of 48,289 participants.
"There is a positive relationship between cultural participation and self-perceived health for both women and men, "says Professor Jostein Holmen, a HUNT researcher who presented the findings, which have not yet been published, at a Norwegian health conference in Stjørdal in late November. "For men, there is also a positive relationship between cultural participation and depression, in that there is less depression among men who participate in cultural activities, although this is not true for women."
The findings are drawn from the latest round of studies conducted for the Norwegian University of Science and Technology's (NTNU) Nord-Trøndelag Health Study, or HUNT, which used questionnaires, interviews, clinical examinations and the collection of blood and urine samples to assemble detailed health profiles of 48,289 participants.
"There is a positive relationship between cultural participation and self-perceived health for both women and men, "says Professor Jostein Holmen, a HUNT researcher who presented the findings, which have not yet been published, at a Norwegian health conference in Stjørdal in late November. "For men, there is also a positive relationship between cultural participation and depression, in that there is less depression among men who participate in cultural activities, although this is not true for women."
© iStockphoto
Attractive women in a city.
Attractive women in a city.
However, the study, published in this month's issue of Personal Relationships, also determines that the importance of attractiveness is not universal; rather, it is determined by where we live.
The importance of attractiveness in everyday life is not fixed, or simply a matter of human nature. Instead, the impact of our attractiveness on our social lives depends on the social environment where we live. Attractiveness does matter in more socially mobile, urban areas (and from a woman's point of view actually indicates psychological well-being), but it is far less relevant in rural areas. In urban areas individuals experience a high level of social choice, and associating with attractive people is one of those choices.
Physical activity is known to reduce depression and fatigue in people struggling with chronic illness. A new study indicates that this effect may stem from an individual's sense of mastery over - or belief in his or her ability to achieve - certain physical goals.
The study appears in the journal Psychosomatic Medicine.
"We base our arguments on fatigue being a symptom of depression," said Edward McAuley, a professor of kinesiology and community health at the University of Illinois and lead author of the study. "Interventions to reduce depression have consistently resulted in reductions in fatigue. The opposite is not always the case."
Depression and fatigue also are highly susceptible to changes in a person's sense of his or her own ability to achieve a certain goal.
The study appears in the journal Psychosomatic Medicine.
"We base our arguments on fatigue being a symptom of depression," said Edward McAuley, a professor of kinesiology and community health at the University of Illinois and lead author of the study. "Interventions to reduce depression have consistently resulted in reductions in fatigue. The opposite is not always the case."
Depression and fatigue also are highly susceptible to changes in a person's sense of his or her own ability to achieve a certain goal.
© iStockphoto
A diet rich in methionine, an amino acid typically found in red meats, fish, beans, eggs, garlic, lentils, onions, yogurt and seeds, can possibly increase the risk of developing Alzheimer's disease, according to a study by Temple researchers.
A diet rich in methionine, an amino acid typically found in red meats, fish, beans, eggs, garlic, lentils, onions, yogurt and seeds, can possibly increase the risk of developing Alzheimer's disease, according to a study by Temple researchers.
"When methionine reaches too high a level, our body tries to protect itself by transforming it into a particular amino acid called homocysteine," said lead researcher Domenico Praticò, an associate professor of pharmacology in the School of Medicine. "The data from previous studies show -- even in humans -- when the level of homocysteine in the blood is high, there is a higher risk of developing dementia. We hypothesized that high levels of homocysteine in an animal model of Alzheimer's would accelerate the disease."
Using a seven-month old mouse model of the disease, they fed one group an eight-month diet of regular food and another group a diet high in methionine. The mice were then tested at 15 months of age -- the equivalent of a 70-year-old human.
There is hope for those who miss one night too many or whose children keep them up at night. The unwelcome effects of a bad night's sleep -- forgetfulness, impaired mental performance -- can be dealt with by reducing the concentration of an enzyme in the brain.
These are the conclusions of research published by Rubicon-grant winner Robbert Havekes and colleagues in the 22 October issue of Nature.
Millions of people are regularly plagued by sleep deprivation. This can lead to both short-term and long-term problems with memory and learning capacity. How sleep deprivation causes these kinds of problems was largely unknown up to now. Havekes and his colleagues discovered that sleep deprivation in mice undermines the function of a specific molecular mechanism in the hippocampus, the area of the brain responsible for consolidating new memories.
These are the conclusions of research published by Rubicon-grant winner Robbert Havekes and colleagues in the 22 October issue of Nature.
Millions of people are regularly plagued by sleep deprivation. This can lead to both short-term and long-term problems with memory and learning capacity. How sleep deprivation causes these kinds of problems was largely unknown up to now. Havekes and his colleagues discovered that sleep deprivation in mice undermines the function of a specific molecular mechanism in the hippocampus, the area of the brain responsible for consolidating new memories.
© Journal of Pediatric Psychology
The bright regions in these scans (at left, a top-down view of the brain; at right, a view of the brain from the back of the head) indicate greater hippocampus activity in healthy children during memory recall than in children with PTSD symptoms.
The bright regions in these scans (at left, a top-down view of the brain; at right, a view of the brain from the back of the head) indicate greater hippocampus activity in healthy children during memory recall than in children with PTSD symptoms.
"The brain doesn't divide between biology and psychology," said Packard Children's child psychiatrist Victor Carrion, MD, the primary author of the new research. "We can use the knowledge we get from understanding brain function to improve the psychology of the individual and vice versa."
Extreme stressors such as experiencing abuse or witnessing violence can make children isolate themselves from family and friends, feel disconnected from reality, experience intrusive thoughts about the trauma and struggle in school. "Post-traumatic stress is not only about the traumatic memories; it really affects daily living," said Carrion, who is an associate professor of child and adolescent psychiatry at the School of Medicine and director of Stanford's early life stress research program. The research will be published online Dec. 8 in the Journal of Pediatric Psychology.
© University of Hertfordshire
Dr. Lovatt in his dancing booth at Hertfordshire.
Dr. Lovatt in his dancing booth at Hertfordshire.
Research conducted by Dr Peter Lovatt from the University's School of Psychology on the BBC Radio 4 Today Programme's website asked people to imagine they were at a party dancing with other people and then asked them to rate how good a dancer they thought they were compared with the average person of their own age and gender.
Almost 14,000 people filled in the Dance Style Questionnaire and the results show that although up to the age of 16, men lack confidence in their dance moves, after that their dance confidence rises steadily with men over the age of 65 having higher ratings than men between the ages of 55 and 60.
Women, on the other hand display immense confidence up to the age of 16, experience a drop between then and 20, and then confidence levels rise steadily up to 35 and then drop steadily between 55 and 65.
MIT and Boston University researchers have discovered that the drug hydroxyurea kills bacteria by inducing them to produce molecules toxic to themselves -- a conclusion that raises the possibility of finding new antibiotics that use similar mechanisms.
Hydroxyurea inhibits the enzyme critical for making the building blocks for DNA, so for decades it has been used to study the consequences of inhibiting DNA replication in E. coli, yeast and mammalian cells. It is also sometimes used in chemotherapy to halt the growth of cancer cells.
The research team, led by biologist Graham Walker of MIT and bioengineer James Collins of Boston University, showed that cells don't die after hydroxyurea treatment because their DNA replication is blocked, but because the blockage sets in motion a chain of cellular events that culminates in the production of hydroxyl radicals. Those radicals are highly reactive and can damage cellular molecules such as nucleic acids, lipids and proteins.
Collins has previously shown that three different antibiotics, which each inhibit different cell processes, all lead to production of hydroxyl radicals, which play a role in killing the cells.
Hydroxyurea inhibits the enzyme critical for making the building blocks for DNA, so for decades it has been used to study the consequences of inhibiting DNA replication in E. coli, yeast and mammalian cells. It is also sometimes used in chemotherapy to halt the growth of cancer cells.
The research team, led by biologist Graham Walker of MIT and bioengineer James Collins of Boston University, showed that cells don't die after hydroxyurea treatment because their DNA replication is blocked, but because the blockage sets in motion a chain of cellular events that culminates in the production of hydroxyl radicals. Those radicals are highly reactive and can damage cellular molecules such as nucleic acids, lipids and proteins.
Collins has previously shown that three different antibiotics, which each inhibit different cell processes, all lead to production of hydroxyl radicals, which play a role in killing the cells.
How do we know that certain combination of letters have certain meanings? Reading and spelling are complex processes, involving several different areas of the brain, but researchers from Johns Hopkins University in the USA have now identified a specific part of the brain -- named the left fusiform gyrus -- which is necessary for normal, rapid understanding of the meaning of written text as well as correct word spelling. Their findings are published in the February 2010 issue of Cortex.
Dr Kyrana Tsapkini, from the Department of Neurology at Johns Hopkins University School of Medicine, and Dr Brenda Rapp, from the Department of Cognitive Science at Johns Hopkins University, studied the reading comprehension and spelling abilities of a patient who had undergone surgical removal of part of his brain due to a tumor. The patient's reading and spelling abilities had been above average prior to the surgery.
They tested the patient and a group of control participants using 17 experimental tasks, which evaluated their comprehension and production of written language, spoken language, as well as their processing of other visual categories such as faces and objects.
Dr Kyrana Tsapkini, from the Department of Neurology at Johns Hopkins University School of Medicine, and Dr Brenda Rapp, from the Department of Cognitive Science at Johns Hopkins University, studied the reading comprehension and spelling abilities of a patient who had undergone surgical removal of part of his brain due to a tumor. The patient's reading and spelling abilities had been above average prior to the surgery.
They tested the patient and a group of control participants using 17 experimental tasks, which evaluated their comprehension and production of written language, spoken language, as well as their processing of other visual categories such as faces and objects.
