A molecule in the brain essential for wakefulness and appetite has been found to play a central role in strengthening the neuron connections that lead to addiction. The discovery of how the neuropeptide orexin works at the molecular level makes it a strong new target for potential drugs to treat addiction, the researchers say. The discovery by neuroscientists at UCSF's Ernest Gallo Clinic and Research Center is being reported February 16 in the journal Neuron. The research focused on orexin's role in strengthening communication between neurons that release dopamine, a brain chemical central to learning and memory. The strengthened communication is known to play a key role in the experience of a drug high and subsequent drug craving. Orexin is produced in the brain's lateral hypothalmus (LH) region. The scientists demonstrated in studies of rats that orexin acutely enhances the ability of receptors at dopamine neuron synapses – known as NMDA receptors – to promote the release of dopamine. They showed that orexin creates a long-lasting potential for strengthened transmission between neurons of the LH region and dopamine-releasing neurons in a brain region known as the ventral tegmental area (VTA). This fundamental change in the neurons, called synaptic plasticity, is known to be critical for new learning and memory formation essential to addiction.

Keyword: Drug Abuse; Sleep
Link ID: 8544 - Posted: 06.24.2010

The medication tetrabenazine cut down involuntary movement in patients with Huntington’s disease on average by about 25 percent, with many patients experiencing a greater improvement, according to a study in the February 14 issue of the journal Neurology. Overall, patients who received the medication were six times as likely to be considered by their doctors to have improved considerably, compared to participants who received a placebo. Dr. Kathleen M. Shannon, neurologist and Huntington’s disease specialist at the Huntington’s Disease Society of America Center of Excellence at Rush University Medical Center, led the Rush study. Rush was one of 16 sites to participate in the randomized, controlled study which involved 84 patients. Tetrabenazin is available in Europe and Canada – but not the United States, but is currently being reviewed by the U.S. Food and Drug Administration. If approved, the medication would be the first authorized by the agency expressly for the treatment of Huntington’s disease, which affects about 30,000 people in the United States. “Huntington’s disease is an inherited brain disorder that causes patients to experience uncontrollable jerky movements (chorea), as well as changes in personality, behavior, thinking and memory. There are no FDA-approved treatments for the chorea. Anti-psychotic drugs like haloperidol (Haldol) are commonly used to suppress chorea, but they cause many different side effects. This study shows that tetrabenazine can decrease chorea, and the drug is well-tolerated by most research subjects,” said Shannon. ©2004 Rush University Medical Center,

Keyword: Huntingtons
Link ID: 8543 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — Appreciation for sweet tastes is hard wired into the brains of most insects and animals, including humans, according to a recent study. Since the study also determined that our brains have a built-in aversion to bitter substances, chocolate would appear to be a neutral food, but its sweetness usually wins people over, even when the chocolate is dark and slightly bitter. "There is a fine balance between bitter and sweet," said Kristin Scott, who led the study, which was published in a recent issue of Neuron. "Even fruitflies will eat bitter substances if the ratio of sugar is high. Coffee drinking is definitely an acquired taste." For the study, Scott and her colleagues monitored the taste responses of the fruit fly Drosophila. Walter Fischler, who assisted in the research, explained to Discovery News that "sometimes nature finds the same solution for the same problem in many different species. Humans have cells that are specialized for certain tastes on the tongue, and these cells could be somewhat mirrored in the brain, similar to how they are in flies." The researchers found that sweet substances activated certain brain neurons called Gr5a. Bitter substances activated different neurons, called Gr66a. Repeatedly, the flies preferred substances that activated the Gr5a neurons, but they avoided consumables that activated Gr66a neurons. © 2006 Discovery Communications Inc.

Keyword: Chemical Senses (Smell & Taste); Obesity
Link ID: 8542 - Posted: 06.24.2010

Helen Pearson Loud noise appears to fuel the effects of the club-drug ecstasy in the brain. The results add to the debate about the risks of long-term brain damage from the drug. Ecstasy is the common name for 3,4-methylenedioxymethamphetamine (MDMA). The drug, popular at raves and nightclubs, triggers a flood of the feel-good chemical serotonin in the brain, causing feelings of euphoria, energy and well-being. Michelangelo Iannone at the Institute of Neurological Science in Catanzaro, Italy, and his colleagues tested whether loud noise intensified ecstasy's effects in rat brains. After injecting the animals with either a low or high dose of MDMA, they played them a buzz of white noise at the maximum volume allowed in Italian nightclubs. They measured the rats' brain activity using electrodes inserted into the animals' skulls. The deafening noise can transform a seemingly innocuous dose of the drug into a potent one, they found. The low dose of MDMA had little effect on the animals' brains - but when paired with the noise, it boosted the activity of certain brain cells. "This may make the difference between the drug being toxic and not," says Jenny Morton at the University of Cambridge, UK, who has studied the effects of music on drugs. ©2006 Nature Publishing Group

Keyword: Drug Abuse; Hearing
Link ID: 8541 - Posted: 06.24.2010

Alison Motluk A new weight loss drug that works by blocking a cannabinoid receptor in the brain has had “modest” success at helping people both lose weight and keep it off, researchers say. It also seemed to improve other risk factors for cardiovascular disease beyond what would be expected from weight loss alone. But critics say the study’s methodology may have been flawed, given that almost half of its participants dropped out. Although 3045 people entered the study, the main results were based only on the 1602 who followed through to the end of the first year. “That may erroneously create a larger effect,” says Denise Simons-Morton, at the US National Heart, Lung and Blood Institute in Bethesda, Maryland, who co-wrote an accompanying editorial about the paper. She and her co-authors suggest the researchers should have made a greater effort to measure final outcomes in all their participants, even those who left early. Xavier Pi-Sunyer, of St Luke’s-Roosevelt Hospital in New York, and his colleagues randomised their obese participants to take daily doses of either 5 milligrams or 20 mg of the drug, called rimonabant, or a placebo. The volunteers were also encouraged to stay on a weight-loss diet and given instruction on how to exercise more. Over the course of a year, various measures were taken, including weight, waist circumference, triglycerides (blood lipids), good cholesterol and blood pressure. © Copyright Reed Business Information Ltd.

Keyword: Obesity; Drug Abuse
Link ID: 8540 - Posted: 06.24.2010

Scientists have devised a probe which can warn if a baby is being deprived of oxygen during birth. It checks for high levels of a chemical called hypoxanthine. The University of Warwick researchers hope it could reduce Caesareans, as doctors currently opt for the operation if there is any doubt at all. Experts said such a test could have huge benefits - but warned much more work was needed before the Warwick probe could be used in hospitals. Current tests for foetal hypoxia - oxygen deprivation - are unreliable and many experts feel they are not specific enough. Not only does this mean that any baby thought to be at any risk is delivered by Caesarean - potentially unecessarily - but they are also given head cooling treatment, which has been shown to minimise the risk of damage from oxygen deprivation. Experts are looking for better ways of targeting the treatment. Professor Nick Dale, the neuroscientist who has led the Warwick research, looked at levels of a chemical in the blood called hypoxanthine. It has been known for some time that high levels indicate a high risk of a child being starved of oxygen - with a measure of more than five micromoles of the chemical per litre of blood indicating a severe risk. But the challenge is to develop a quick and easy test which can be used on the ward. (C)BBC

Keyword: Development of the Brain
Link ID: 8539 - Posted: 02.16.2006

Researchers at The Hospital for Sick Children (SickKids) have found that intravenous morphine used alone or with a topical anaesthetic (tetracaine) effectively reduced levels of pain in newborn infants undergoing insertion of central venous catheters (central lines). This research is reported in the February 15, 2006 issue of the journal JAMA. About 10 to 15 per cent of newborns require prolonged hospitalization for conditions such as preterm birth, congenital defects and sepsis (a blood stream infection). As part of their medical care, these infants are often exposed to multiple invasive procedures that may be painful. "It was not so long ago that infants routinely underwent painful procedures without the benefits of analgesia. Our previous studies showed that infants do feel extreme pain, that they remember this pain and that it affects their future pain responses," said Dr. Anna Taddio, the study's lead author and principal investigator, a SickKids scientist and pharmacist, and an assistant professor of Pharmacy at the University of Toronto. "Within the last decade, the pendulum started to swing in the other direction, and pain relievers began to be used more liberally in infants. However, more information was needed about the benefits and risks of the different treatment options. We undertook this study to determine the most effective way to manage pain in infants undergoing central line placements and to delineate the side effects associated with their use," said Dr. Taddio.

Keyword: Pain & Touch; Development of the Brain
Link ID: 8538 - Posted: 02.16.2006

Gay "marriage" could boost the mental and physical health of homosexuals, doctors believe. Rates of depression, drug abuse and cancer are higher in the gay community than among heterosexual people. The report said civil partnerships, which were introduced in England and Wales in December, were likely to reduce prejudice and social exclusion. The Journal of Epidemiology and Community Health article was based on previous studies in other countries. Denmark was the first country to introduce civil partnerships for same sex couples in 1989, since when several European Union countries, some US states, Australia and Canada have followed suit. Professor Michael King, of University College London, who co-wrote the article, said: "Civil partnerships are likely to break down some of the prejudice and promote greater understanding, including among staff working in the health service. "Legal civil partnerships could increase the stability of same sex relationships and minimise the social exclusion to which gay and lesbian people are often subjected." Research has shown that lesbians have higher risk of breast cancer, heart disease and obesity, while gay men have a higher risk of HIV, the article said. Gay people are also more likely to suffer from depression, drug abuse and suicidal urges than heterosexual people. (C)BBC

Keyword: Sexual Behavior; Depression
Link ID: 8537 - Posted: 02.14.2006

Where were we before we got sidetracked? It's tempting to blame cell phones, iPods and satellite radios for our distractibility, say researchers. But the more likely culprit is the aging brain. Changes in brain activity that begin gradually in middle age may explain why older adults find it hard to focus in busy environments, according to a study in this month's Journal of Cognitive Neuroscience. Canadian researchers compared brain scans of adults of various ages who were given a series of memory tasks. They found that advancing age inhibited the ability to turn off background chatter and concentrate on the task at hand. "Young adults can do this really well," said lead author Cheryl Grady, senior scientist with the Rotman Research Institute at Baycrest in Toronto. "This difference becomes less distinct in middle-age adults and is even less distinct in older adults." Seeking Focus One way to cope better: Limit multi-tasking. "Multi-tasking is a colloquial expression for what we refer to as a divided-attention problem," said David Madden, professor of medical psychology at Duke University Medical Center. "When people have to divide their attention, it's harder to concentrate." © 2006 The Washington Post Company

Keyword: Attention; Alzheimers
Link ID: 8536 - Posted: 06.24.2010

By SALLY SATEL, M.D. As a psychiatrist at a methadone clinic, I rarely encounter patients waving advertisements for the newest antidepressant or sleeping pill. Consumer-consciousness is just not big among our clientele. So I was surprised when a patient asked about "that pill for gambling addiction — maybe it would work for cocaine addiction, too." Ted was a 36-year-old heroin addict who stopped using once he began methadone but whose continuing cocaine habit increased in turn. Earlier that morning he heard a story on National Public Radio about a pill that helped pathological gamblers. "The gambler on the radio said the medication made him stop 'climbing the walls' and that he wasn't craving anymore," Ted told me. "That's what I need, something to make me not want." That, of course, is the timeless quest of addicts in recovery: not to want. More specifically, effortlessly not to want. But the very idea of a drug to treat addiction rankles others. Some experts are skeptical of substitution drugs, like methadone, because they produce dependence themselves. Others believe that treatment should break the addict's Pavlovian link between quick-fix relief and pill-taking. And psychotherapists often want a patient to feel the pain of his psychic conflicts in order to resolve them and thus eradicate the root cause of his addiction. Copyright 2006 The New York Times Company

Keyword: Drug Abuse
Link ID: 8535 - Posted: 06.24.2010

By ALIX SPIEGEL For most of the 20th century, therapists in America agreed on a single truth. To cure patients, it was necessary to explore and talk through the origins of their problems. In other words, they had to come to terms with the past to move forward in the present. Thousands of hours and countless dollars were spent in this pursuit. Therapists listened diligently as their patients recounted elaborate narratives of family dysfunction — the alcoholic father, the mother too absorbed in her own unhappiness to attend to her children's needs — certain that this process would ultimately produce relief. But returning to the past has fallen out of fashion among mental health professionals over the last 15 years. Research has convinced many therapists that understanding the past is not required for healing. Despite this profound change, the cliché of patients' exhaustively revisiting childhood horror stories remains. "Average consumers who walk into psychotherapy expect to be discussing their childhood and blaming their parents for contemporary problems, but that's just not true any more," said John C. Norcross, a psychology professor at the University of Scranton in Pennsylvania. Copyright 2006 The New York Times Company

Keyword: Depression; Schizophrenia
Link ID: 8534 - Posted: 06.24.2010

By MARK DERR I was drinking coffee in the kitchen one night a few years ago when I heard, emanating from our stereo system two rooms away, the unmistakable voice of Marilyn Monroe singing "Happy Birthday, Mr. President." Startled, I asked my wife, Gina, what that recording was doing on our stereo. "You're hallucinating," she said. "That's the Grateful Dead. It's not even close to 'Happy Birthday,' much less Marilyn Monroe." I think I have seen one Marilyn Monroe movie in its entirety, and I don't recall its title. Many years ago, I saw a film clip of her performance at Madison Square Garden in celebration of President John F. Kennedy's birthday. Despite Gina's assurances, I continued to hear Marilyn singing until I walked into the next room and met the familiar sound of Jerry Garcia and the Grateful Dead. We concluded that I had somehow conflated the Dead's song "Uncle John's Band" with some faint music from the next-door neighbor's house and transformed the two streams of sound into something completely different. The dopamine agonist I had started taking a few months earlier for Parkinson's disease carried a warning that hallucinations were a possible side effect. It had already caused sleep attacks, so, I thought, why not hallucinations? Copyright 2006 The New York Times Company

Keyword: Parkinsons
Link ID: 8533 - Posted: 02.14.2006

By NICHOLAS WADE When rats pause in running through a maze, they play back their memory of points along their route, but in reverse order. The discovery may provide a deep insight into how memory works in humans, as well as in rats. The reverse replay mechanism seems to be part of a neural editing process in which memories are selected, combined and stored as a set of edited movies, as it were, of important experiences in life. The mechanism was discovered by David J. Foster and Matthew A. Wilson at the Massachusetts Institute of Technology while they were studying the behavior of neurons in the rat's hippocampus, a brain region where new memories of location are formed. Their finding is reported in an article published online on Sunday by the journal Nature. The researchers were able to detect the reverse replay because of a set of electrodes that were stuck into individual neurons in the hippocampus. These neurons are known as place cells because each responds to a specific location in the rat's surroundings, in this case points along the maze. Though scientists have been aware of place cells for years, reverse replay had not been seen before because it occurs when the rats pause in the maze and seem to be doing nothing, Dr. Wilson said. Researchers had ignored this behavior because it did not seem to be important. Copyright 2006 The New York Times Company

Keyword: Learning & Memory
Link ID: 8532 - Posted: 02.14.2006

By Bjorn Carey To figure out how we pick mates, scientists have measured every shape and angle of the human face, studied the symmetry of dancers, crafted formulas from the measurements of Playboy models, and had both men and women rank attractiveness based on smelling armpit sweat. After all this and more, the rules of attraction for the human species are still not clearly understood. How it all factors into true love is even more mysterious. But a short list of scientific rules for the game of love is emerging. Some are as clearly defined as the prominent, feminine eyes of a supermodel or the desirable hips of a well-built man. Other rules work at the subconscious level, motivating us to action for evolutionary reasons that are tucked inside clouds of infatuation. In the end, lasting love depends at least as much on behavior as biology. But the first moves are made before you're even born. Starting at conception, the human body develops by neatly splitting cells. If every division were to go perfectly, the result would be a baby whose left and right sides are mirror images. But nature doesn't work that way. Genetic mutations and environmental pressures skew symmetry, a process with lifelong implications. © 2006 MSNBC.com © 2006 Microsoft

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 8531 - Posted: 06.24.2010

Seven-month-old infants cannot talk, nor can they do arithmetic. But a new study seems to show that babies do have an inherent sense of numbers, regardless of whether they can add two and two to get four. Neuroscientists Kerry Jordan and Elizabeth Brannon had previously shown that rhesus monkeys have a natural ability to match the number of voices they hear to the number of individuals they expect to see. When presented with a soundtrack of "coo" sounds, the monkeys chose to look at a picture containing the same number of fellow monkey faces. If the monkeys heard two coos, for example, they preferred to look at a picture of two monkeys rather than three and vice versa. The researchers expected the same to be true of human babies. But other studies with infants had delivered ambiguous results. Babies trained to expect to see two objects when presented with two tones stared longer at results that violated this convention, such as two tones and then three objects. And although babies matched up drumbeats and household objects in one study, efforts to duplicate the result failed. Jordan and Brannon argue that each of these studies was flawed, either because training might have skewed the response, or because the tasks were too difficult or the objects were irrelevant to a baby. © 1996-2006 Scientific American, Inc.

Keyword: Development of the Brain
Link ID: 8530 - Posted: 06.24.2010

Electroconvulsive therapy (ECT) – shock treatment –improves quality of life in patients with major depression, and that improved quality of life continues for six months, according to a report in the February Journal of Affective Disorders. The study was conducted in seven hospitals in New York City – two private psychiatric hospitals, three community hospitals and two academic medical centers, said W. Vaughn McCall, M.D., M.S., the lead author and professor and chairman of the Department of Psychiatry and Behavioral Medicine at Wake Forest University School of Medicine. "This study adds to the accumulating evidence that ECT is associated with a net health benefit in depressed patients who attain and sustain remission," wrote McCall and colleagues. ECT has long been known to be an effective treatment for major depression. The results from 283 severely depressed patients at the seven New York City hospitals confirm results from an earlier study McCall did of 77 ECT patients at Wake Forest University Baptist Medical Center, a study that was published in the November 2004 issue of the British Journal of Psychiatry. In that study, he said, "Quality of life and function are improved in ECT patients as early as two weeks after the conclusion of ECT." In the new study, the psychiatrists said, "ECT is associated with improved health-related quality of life in the short term and the long term." Most of the improvements were largely explained by the control of depressive symptoms, McCall said.

Keyword: Depression
Link ID: 8529 - Posted: 06.24.2010

All is fair in love and war — especially when the two are intertwined. Just ask the male Australian cuttlefish. "The male cuttlefish has quite a challenge on his hands when it comes to the end of their yearly life cycle," explains Roger Hanlon, senior scientist at the Marine Biological Laboratory. "There are four, five, even ten males for every female on the spawning grounds, so the challenge they face is, 'How do I get my genes into the next generation?' There's enormous competition among the males for the relatively few females that are on the spawning ground." Hanlon and his team spent five spawning seasons observing cuttlefish underwater in a remote coastal area of Australia. As one might expect, the largest males used their size advantage to find a female partner and guard her from other males. Hanlon observed that smaller males were able to get to the female while the guard male was fighting other males away, or by meeting the female in a "secret rendezvous" under a rock, for instance. But he found that the small males with the biggest success rate employ the same camouflage trick that allows them to escape predators: these so-called "sneaker" males change their skin pattern and body shape to disguise themselves as females, and swim right past a large guard male, who thinks he's getting another girlfriend. © ScienCentral, 2000-2006.

Keyword: Sexual Behavior
Link ID: 8528 - Posted: 06.24.2010

Researchers at a trio of universities have found that reactivating a specific memory does not affect associated or related memories, adding to our understanding of how memories are stored and influenced. The study appears in the latest issue of the Proceedings of the National Academy of Sciences. The study's authors are Jacek Debiec and Joseph LeDoux of New York University's Center for Neural Science, Valérie Doyère of NYU and Université Paris-Sud, and Karim Nader, a psychology professor at McGill University. Memories are made in stages. These initial stages involve learning followed by consolidation--a process during which the memory trace is formed. Unconsolidated memories are susceptible to disruption. Therefore, various pharmacological agents or interfering tasks applied before consolidation occurs prevent a memory from persisting. However, once consolidation occurs, memories may be long lasting--one experience may create memories that last a lifetime. For years it had been believed that consolidated memories were resistant to drug manipulations, which are effective in the early stages of memory formation. However, increasing number of data indicate that reactivation of consolidated memories renders them susceptible to treatments, which may result in either impairment or enhancement of the reactivated memory. This process is often referred to as reconsolidation, which has been proposed as a possible way of treating traumatic memories.

Keyword: Learning & Memory; Emotions
Link ID: 8527 - Posted: 02.14.2006

Up to 80% of the risk of developing Alzheimer's disease is genetic, a study has suggested. US researchers looked at almost 400 sets of elderly twins, where at least one had Alzheimer's. It also found that genetic factors appeared to determine when a person developed the condition. UK experts said the research, published in the journal Archives of General Psychiatry, would help quantify the role genetics played. Two-thirds of adults aged 65 years and older with dementia have Alzheimer's. The number of cases is expected to rise with the growing older adult population. Gene mutations which could affect risk have been found, but it is thought they only apply to a tiny number of cases. Scientists trying to determine whether genetic or environmental factors influence disease risk often study twins. Identical (monozygotic) twins share all their genes. So if a disease does have a strong genetic basis, it is likely to be seen in both or neither. But if only one has a condition, it is likely that environmental factors play a relatively greater influence. In the US study, researchers from the University of Southern California, Los Angeles, and colleagues identified 392 pairs of twins where one or both had Alzheimer's from the Swedish Twin Registry. (C)BBC

Keyword: Alzheimers; Genes & Behavior
Link ID: 8526 - Posted: 02.13.2006

Helen Pearson Idlers, loafers and layabouts, listen up. A new study suggests that the times when we sit around twiddling our thumbs could in fact be vital for learning. The idea stems from experiments in which neuroscientists eavesdropped on the brains of rats as they explored their environments. They found that the rats' brains 'replay' their experiences in reverse when the animals pause briefly to rest. The scientists, David Foster and Matthew Wilson working at the Massachusetts Institute of Technology in Cambridge, inserted a pincushion of fine wires into the animals' skulls. These allowed the team to simultaneously monitor the electrical activity of around 100 individual brain cells in the hippocampus, a brain region involved in learning and memory. The researchers placed each wired-up rat in a straight 1.5-metre run. They recorded brain-cell activity as the rats scurried up and down, pausing at each end to eat, groom and scratch their whiskers. As the rats ran along the track, the nerve cells fired in a very specific sequence. This is not surprising, because certain cells in this region are known to be triggered when an animal passes through a particular spot in a space. But the researchers were taken aback by what they saw when the rats were resting. Then, the same brain cells replayed the sequence of electrical firing over and over, but in reverse and speeded up. "It's absolutely original; no one has ever seen this before at all," says Edvard Moser, who studies memory at the Norwegian University of Science and Technology in Trondheim. ©2006 Nature Publishing Group

Keyword: Learning & Memory
Link ID: 8525 - Posted: 06.24.2010