Researchers at the University of California, San Francisco (UCSF) and New York University have discovered a gene mutation in fruit flies that alters sensitivity to crack cocaine and also regulates their internal body clock. The findings, reported in the December issue of Public Library of Science (PLoS) Biology, may have implications for understanding innate differences in sensitivity to cocaine in humans, potentially providing targets for development of drugs to treat or prevent addiction. Headed by UCSF's Ulrike Heberlein, the research team discovered a mutation of the Drosophila LIM-only (Lmo) gene. Normal fruit flies increase their activity when exposed to low doses of crack cocaine over a one-minute period. At medium levels, fruit flies exhibit frenzied, jerky motions. At high doses, the flies become immobile. However, flies with the Lmo gene mutated were much more sensitive to crack cocaine and became immobile at much lower levels than normal fruit flies. Heberlein's group also showed that Lmo is normally produced in the pacemaker neurons that control 24-hour--or circadian--rhythms of sleep/wake cycles in flies. Comprising about 10 cells per hemisphere, these neurons provide the fly with an internal clock, driving circadian rhythms of behavior even in the absence of light. While Lmo is found throughout the body, it is enriched in the brain. By expressing normal Lmo in over-sensitive mutants, the researchers discovered that Lmo's cocaine-related effects were localized to the circadian pacemaker neurons.

Keyword: Drug Abuse; Biological Rhythms
Link ID: 6465 - Posted: 11.23.2004

By Roger A. Nicoll and Bradley N. Alger Marijuana is a drug with a mixed history. Mention it to one person, and it will conjure images of potheads lost in a spaced-out stupor. To another, it may represent relaxation, a slowing down of modern madness. To yet another, marijuana means hope for cancer patients suffering from the debilitating nausea of chemotherapy, or it is the promise of relief from chronic pain. The drug is all these things and more, for its history is a long one, spanning millennia and continents. It is also something everyone is familiar with, whether they know it or not. Everyone grows a form of the drug, regardless of their political leanings or recreational proclivities. That is because the brain makes its own marijuana, natural compounds called endocannabinoids (after the plant's formal name, Cannabis sativa). The study of endocannabinoids in recent years has led to exciting discoveries. By examining these substances, researchers have exposed an entirely new signaling system in the brain: a way that nerve cells communicate that no one anticipated even 15 years ago. Fully understanding this signaling system could have far-reaching implications. The details appear to hold a key to devising treatments for anxiety, pain, nausea, obesity, brain injury and many other medical problems. Ultimately such treatments could be tailored precisely so that they would not initiate the unwanted side effects produced by marijuana itself. Marijuana and its various alter egos, such as bhang and hashish, are among the most widely used psychoactive drugs in the world. How the plant has been used varies by culture. The ancient Chinese knew of marijuana's pain-relieving and mind-altering effects, yet it was not widely employed for its psychoactive properties; instead it was cultivated as hemp for the manufacture of rope and fabric. © 1996-2004 Scientific American, Inc.

Keyword: Drug Abuse
Link ID: 6464 - Posted: 06.24.2010

by Kiran Rabheru, M.D. The occurrence of neuropsychiatric symptoms in dementia patients has been well established (Rovner et al., 1990). Of patients with Alzheimer's disease (AD), 78% suffer depressive symptoms, 77% have agitation and 69% have psychotic symptoms, with over half experiencing all three symptoms (Tractenberg et al., 2003). The diagnosis and treatment of mood symptoms in this population remains a challenge for physicians (Harman et al., 2002). It is important to recognize and treat these neuropsychiatric symptoms, as they result in increased morbidity, mortality and health care costs (Janzing et al., 1999). Mandatory depression screening in nursing homes can improve treatment rates (Cohen et al., 2003). Major depression and other, less severe forms of depression frequently form part of the clinical presentation of dementia. Depression with reversible cognitive impairment may be a prodrome for dementia rather than a separate and distinct disorder (Janzing et al., 1999). Depression may be challenging to assess in a patient with dementia. In patients with AD, the presence of depression may range from 6% to 30%, depending on the diagnostic criteria employed (Cummings et al., 1995). The prevalence and course of depression in dementia are controversial, due to several confounding factors. Family members tend to report much greater levels of depression in patients than do clinicians. © 2004 Psychiatric Times. All rights reserved.

Keyword: Alzheimers; Depression
Link ID: 6463 - Posted: 06.24.2010

by Ruth M. Benca, M.D., Ph.D., and Timothy Juergens, M.D. We sleep for one-third of our lives, more time than we spend in any other single behavior, yet sleep is still a mystery in many ways. The high rates of comorbidity between sleep disturbance and psychiatric and medical disorders, however, suggest that sleep is important for normal regulation of physiology and behavior. Insomnia is by far the most common sleep complaint, and it may include difficulty falling asleep, difficulty staying asleep and/or nonrestorative sleep, with significant daytime consequences, often including daytime fatigue (Anonymous, 1999). In the general adult population, complaints of insomnia have a prevalence of about 30% (Ford and Kamerow, 1989; Mellinger et al., 1985), and severe insomnia affects 10% to 15% of the population (Ancoli-Israel and Roth, 1999). Unfortunately, patients with insomnia are frequently undiagnosed and/or untreated (Ancoli-Israel and Roth, 1999). This lack of attention to insomnia may be due in part to the failure to recognize its significant interactions with psychiatric and medical illnesses. The increased prevalence of insomnia in patients with psychiatric disorders is not surprising given that sleep disturbance is part of the diagnostic criteria for many disorders, particularly mood and anxiety disorders. Sixty percent to 90% of patients seeking treatment for depression complain of sleep disruption (Hamilton, 1989; McCall et al., 2000; Perlis et al., 1997). There is also an increased incidence of insomnia in patients with anxiety disorders, with rates of 50% to 70% reported in generalized anxiety disorder and 60% to 80% in panic disorder, as well as elevated rates of sleep disturbance in posttraumatic stress disorder, where difficulty with sleep is part of the diagnostic criteria (Anderson et al., 1984; Mellman et al., 1995; Uhde et al., 1984). Many patients with psychiatric disorders complain of sleep difficulties not only during acute illness but also during periods of remission (Reynolds et al., 1991). Copyright 1995-2004 CME LLC

Keyword: Sleep; Depression
Link ID: 6462 - Posted: 11.23.2004

A University of Southern California biomedical engineer's pioneering brain cell research has led directly to a patented system that is now being rolled out to stem gun violence on the streets of Chicago and Los Angeles. The engineer is Theodore Berger, director of the USC Center for Neural Engineering whose life's work has been deciphering the way in which nerve cells code messages to each other. Now, a camera-and-microphone surveillance system is using his insights to recognize -- instantly, and with high accuracy - the sound of a gunshot, and only a gunshot within a two-block radius. It can then locate, precisely, where the shot was fired; turn a camera to center the shooter in the camera viewfinder, and make a 911 call to a central police station. The police can then take control of the camera to track the shooter and dispatch officers to the scene. The city of Chicago is now installing the first five of 80 of the devices in high crime neighborhoods. In Los Angeles County, Sheriff Lee Baca is now soliciting community involvement and participation to deploy 10 of the units in a pilot test, to be followed by more if the results are successful.

Keyword: Hearing
Link ID: 6461 - Posted: 11.23.2004

By RISHENG XU According to a recent study by Harvard researchers—including the University’s provost—cocaine addiction may be caused by more than simple use of the drug. Released last Thursday in the journal Neuron, the article indicates that certain people may have a genetic predisposition toward cocaine addiction, raising important public policy issues and ethical questions about the nature of addiction. According to Hans C. Breiter, co-director of the Motivation and Emotion Neuroscience Collaboration (MENC) and senior author of the study, this key discovery lies in the structural differences within a specific part of the brains of cocaine addicts. This section of the brain, the amygdala, is responsible for creating the feeling of craving, according to Breiter, who is also an assistant professor of psychiatry at Harvard Medical School. More importantly, he said, the amygdala allows people to see potentially harmful outcomes of their actions, thus serving as a deterrent for most people from abusing drugs. “Cocaine addicts have a terrible time seeing negative consequences of their actions—this is why they have to ‘hit bottom,’” said Breiter. Copyright © 2004, The Harvard Crimson Inc.

Keyword: Drug Abuse; Emotions
Link ID: 6460 - Posted: 06.24.2010

Ion channels made light sensitive, allowing remote control of firing Berkeley -- Scientists at the University of California, Berkeley, have given "blind" nerve cells the ability to detect light, paving the way for an innovative therapy that could restore sight to those who have lost it through disease. A team lead by neurobiologist Richard H. Kramer, UC Berkeley professor of molecular and cell biology, and Dirk Trauner, assistant professor of chemistry, inserted a light-activated switch into brain cells normally insensitive to light, enabling the researchers to turn the cells on with green light and turn them off with ultraviolet light. This trick could potentially help those who have lost the light-sensitive rods and cones in their eyes because of nerve damage or diseases such as retinitis pigmentosa or age-related macular degeneration. In these cases, the photoreceptor cells are dead, but other nerve cells downstream of the photoreceptors are still alive. In particular, retinal ganglion cells, which are the third cell in the path from photoreceptor to brain, could take over some of the functions of the photoreceptors if they could be genetically engineered to respond to light. Kramer envisions a device, reminiscent of the eyepiece worn by the blind Geordi La Forge in "Star Trek – The Next Generation," that would provide some semblance of the real world.

Keyword: Vision
Link ID: 6459 - Posted: 06.24.2010

It depends on what we're thinking about! Toronto, CANADA -- What happens in the brain when we remember our own past? Researchers are using functional magnetic resonance imaging (fMRI) to probe brain activity in search of the answer. According to a new fMRI study using a "diary" method to collect memories, it all depends on what we're thinking about! Researchers have known for decades that thinking about autobiographical facts is different from thinking about autobiographical episodes that happened only once. Since both kinds of thoughts can occur at the same time when people talk about their past, researchers have struggled to find an effective way to separate them. The new study, published in the current issue of the Journal of Cognitive Neuroscience (16:9), is the first brain imaging study of its kind to use diary-like memories collected by volunteers. It was led by The Rotman Research Institute at Baycrest Centre for Geriatric Care. Over a period of several months prior to the brain scan, volunteers documented dozens of unique events from their personal lives on a micro cassette recorder (episodic memories). At the same time, they recorded statements about personal facts of their lives (semantic memories). The researchers played these recordings back to the volunteers while their brains were being scanned with fMRI.

Keyword: Learning & Memory
Link ID: 6458 - Posted: 11.23.2004

A type of drug used to treat schizophrenia can protect brain cells from a virus that causes a fatal nervous system disorder, say experts. The disorder is called progressive multifocal leukoencephalopathy or PML. It affects people with weakened immune systems, such as people with Aids or organ transplant patients. A US study in Science found the antipsychotic drug clozapine appeared to be most effective at preventing the infection without side-effects. PML is caused by a virus which destroys glial cells that produce the fatty sheath that covers nerve cells. Most people carry the virus. But a healthy immune system suppresses it, and it only causes PML in people with weakened immune systems. The symptoms of PML include dementia, vision loss, movement and speech impairment, paralysis and coma. The condition is always fatal. The scientists found the virus attaches itself to a receptor on the surface of glial cells. That receptor opens and allows the virus to get inside cells. It normally binds with serotonin, a brain chemical that plays an important role in depression and anxiety, leading the scientists to investigate if medications which act as serotonin-receptor blockers could be effective. The team at Brown University and Case Western Reserve University focussed on a particular protein, called clathrin within the cells, which plays a role in bringing substances into the cell. They then tested drugs to see which might be effective in blocking the action of this protein. Chlorprozamine, a drug used to control psychotic symptoms such as hallucinations and delusions, was found to work. But it can cause serious side effects, such as lowered blood pressure, stiffness and tremors. This led the team to test seven similar drugs. They found that three others, most notably the antipsychotic clozapine, also prevented infection in human glial cells without the side effects. (C)BBC

Keyword: Schizophrenia; Glia
Link ID: 6457 - Posted: 11.21.2004

By RALPH BLUMENTHAL - It's a burning issue for some hot-pepper lovers: Whatever possessed Kevin M. Crosby to create the mild habanero? For Dr. Crosby, a plant geneticist at the Texas A&M Agricultural Experiment Station here near the Mexican border, the answer is simple: "I'm not going to take away the regular habanero. You can still grow and eat that, if you want to kill yourself." But for those who prize the fieriest domesticated Capsicum for its taste and health-boosting qualities, Dr. Crosby and the research station in the Rio Grande Valley have developed and patented the TAM Mild Habanero, with less than half the bite of the familiar jalapeño (which A&M scientists also previously produced in a milder version). With worldwide pepper consumption on the rise, according to industry experts, the new variety - a heart-shaped nugget bred in benign golden yellow to distinguish it from the alarming orange original, the common Yucatan habanero - is beginning to reach store shelves, to the delight of processors and the research station, which stands to earn unspecified royalties if the new pepper catches on. "I love it," said Josh Ruiz, a local farmer whose pickers this week filled some 200 boxes of the peppers to be sold to grocers for about $35 a box. "It yields good and I'm able to eat it." As for the Yucatan habanero, he said, "My stomach just can't take it." Copyright 2004 The New York Times Company

Keyword: Pain & Touch
Link ID: 6456 - Posted: 11.21.2004

Functional MRI shows genetic effects on the human brain more clearly By Jack Lucentini Deciphering genetic relationships in cognitive function takes serious effort. Michael Posner at the University of Oregon in Eugene and colleagues found that a diminished ability to focus could be linked to two specific mutations.1 The study involved a battery of genetic and cognitive tests given to more than 200 people. A year later, in 2003, Posner added clarity to the finding using functional magnetic resonance imaging (fMRI). The researchers linked the mutations to differing activity in the anterior cingulate cortex.2 This study required only 16 subjects. Though some might question the use (and abuse) of fMRI data, others say that neuroimaging is an unexpectedly powerful way to study genetic effects on brain function. Effects show up more obviously in scans than in behavior. "I think everybody has been surprised by the power of imaging strategies," says Daniel Weinberger, a senior investigator at the National Institutes of Health. Researchers say future studies of this type should clarify gene-gene interactions at one of their most befuddling crossroads, the human brain. Imaging technology is largely believed to demonstrate active areas of the brain, something that can't be recorded using cognitive tests. "The closer you get to how genes work, the stronger the effects of the gene are," says Michael Egan, also at the NIH. Egan and colleagues found that a common variant in the gene coding catechol-O-methyltransferase (COMT) boosts schizophrenia risk by 50%.3 They also found that the variant has a more common effect-- it slightly worsens working memory--and an even more frequent one evident only on scans: It reduces efficiency of prefrontal cortex function during working memory tasks. Genetic effects are much more blatant in the brain than in behavior, says Weinberger. "[Genes] code for simple molecules and cells. There are a lot of steps between a gene and the behavior." © 2004, The Scientist LLC,

Keyword: ADHD; Genes & Behavior
Link ID: 6455 - Posted: 06.24.2010

By Laura Spinney Epilepsy often develops after the brain is damaged, and patients commonly must take anticonvulsant drugs for a lifetime despite unpleasant side effects. Such drugs target the seizures but not the underlying cause. Now, new theories promise to untangle the mechanisms of epileptogenesis and presage the possibility of a new generation of drugs that treat the initial brain damage and prevent epilepsy from developing. In roughly half of all patients with epilepsy, the condition develops later in life after the patient sustains a brain injury such as trauma or meningitis. The latency of onset can range from a few weeks to a decade after brain damage occurs. Researchers have been scrambling to uncover what happens during that delay. SIMPLE BALANCE A generally held theory suggests that something upsets the balance of excitatory and inhibitory signals in the brain, leading to overall hyperexcitability. This theory rests on observations that inhibitory cells become less active while excitatory pathways multiply, implying "a simple balance of inhibition and excitation," according to John Duncan of the Institute of Neurology in London. He says that this theory is probably wrong, or at least incomplete. "The reality is clearly more complicated, as neurons form intricate networks and interconnections." © 2004, The Scientist LLC,

Keyword: Epilepsy
Link ID: 6454 - Posted: 06.24.2010

Parents dismayed as Supreme Court refuses to enshrine kids' treatment in constitution The B.C. government is not obligated to provide expensive early-intervention therapy for autistic children, the Supreme Court of Canada ruled Friday in a key decision that has much wider ramifications for all provincial governments. The court's unanimous decision refusing to elevate health funding to a constitutional right overturned two B.C. court rulings that found the province violated the Charter of Rights equality guarantees for disabled people. B.C. Attorney General Geoff Plant said the ruling means governments and not the courts are clearly responsible for social policy and health-care decisions. The earlier B.C. court decisions said the province had discriminated against four autistic children named in a lawsuit by not providing them with Lovaas treatment, an early intensive behavioural therapy which can cost up to $60,000 per child annually. Autism is a neuro-behavioural syndrome that impairs communication and social interaction, often resulting in repetitive behaviour. Lovaas therapy, pioneered by U.S. psychologist Ivar Lovaas, includes 20 to 40 hours of therapy per week and has produced dramatic results in some cases. Some B.C. parents have gone through extremely difficult financial times to fund the program themselves. Copyright © 2004 CanWest Interactive Inc.

Keyword: Autism
Link ID: 6453 - Posted: 06.24.2010

A charity set up after the death of a Bradford schoolgirl is highlighting the dangers of substance abuse. The Chantelle Bleau Memorial Fund hosted a national conference in Bradford on Friday to alert people to the dangers of solvents. Chantelle, 16, a former classmate of pop star Gareth Gates, died in December 1996 after inhaling gas from a lighter refill. The pop star said her death was an appalling waste of a young life. Gareth Gates said: "Chantelle was bright, bubbly and full of fun and her death came as an enormous shock to all of her school friends. "That is why I have always been an enthusiastic supporter of the charity set up in her memory to highlight the enormous dangers of sniffing and inhaling toxic substances such as butane gas. "I am full of admiration for Chantelle's family setting up this charity and to all the staff and volunteers who give so much dedicated time to making people aware how serious this problem is." A charity spokesman said on average five youngsters die each month of solvent abuse. Of those, one in four is a first time user. The conference was jointly hosted with Solve It, a charity which advises parents on solvent issues. (C)BBC

Keyword: Drug Abuse
Link ID: 6452 - Posted: 11.20.2004

Nancy Pinsker ticks off the names of five blue items, noting last the sky. She's better at this than she was five years ago when a stroke put a stranglehold on her vocal muscles, altering her speech. Since then, she's been chipping away at reclaiming the capacity for normal conversation. "I feel if I don't come here and take lessons, I'll lose my voice," says the retired bookkeeper, now in her seventies. "Even now, it's not perfect." For people like Pinsker who find it hard to engage in conversation, a host of new technology awaits. "There's just been an explosion," says Stephen Cavallo, a speech-language pathologist and associate professor at Lehman College, where Pinsker frequents the Speech and Hearing Center. Now NASA researchers are taking a leap in the direction of deciphering speech. Neuroengineer Chuck Jorgensen told Discover Magazine that he's bypassing the physical body's normal requirements by delivering words via machine using subvocal speech. "When you're reading material…sometimes you find that your tongue or your lips are quietly moving but you're not making an audible sound," he explains. "And it's doing that because there's this electronic signal that's being sent to produce that speech but you're intercepting it so it doesn't really say it out loud. That's subvocal speech." © ScienCentral, 2000- 2004.

Keyword: Language
Link ID: 6451 - Posted: 06.24.2010

An electronic "artificial eye", developed for people with impaired vision, has been shown to reliably identify pedestrian crossings, determine when it is safe to walk across and even measure the width of a road. The system, created by Tadayoshi Shioyama and Mohammad Uddin, at the Kyoto Institute of Technology in Japan, consists of a single miniature camera that can be clipped onto a pair of glasses and a small wearable computer that analyses video images. The artificial eye can identify Japanese pedestrian crossings by recognising the white stripes painted across the centre of a road. It can also tell when the signal is flashing to indicate that it is safe to cross. In testing, it successfully identified a crossing 196 times out of 198 and never “found” a crossing where there was not one. Furthermore, the system can measure the distance of a crossing to within the accuracy of a single step. The length of the crossing - the width of the road - is calculated using projective geometry. Some, but not all, pedestrian crossing systems beep to let blind pedestrians know when to cross. This system "relays information using a voice speech system and gives vocal commands and information through a small speaker placed near the ear," says Shioyama. © Copyright Reed Business Information Ltd.

Keyword: Vision; Robotics
Link ID: 6450 - Posted: 06.24.2010

New Haven, Conn.--Imaging studies of the brain when it is under the influence of alcohol reveal that different areas of the brain are impaired under high and low levels of alcohol, according to a Yale study published in Neuropsychopharmacology. Godfrey Pearlson and Vince Calhoun, researchers in the Department of Psychiatry at Yale School of Medicine, used a statistical method to sort areas of the brain affected when persons were administered a placebo or two different doses of alcohol. The seven men and two women then "drove" using a simulated driving skill game. "What we found is that when people were really intoxicated, they drove like they were really intoxicated and in a real vehicle," Pearlson said. "They speeded up, especially on corners, where most people slow down, and crashed more often into other vehicles." When mildly intoxicated, but below the legal alcohol limit, he said, the drivers seemed aware of the fact that they were impaired and corrected for the deficit. The researchers also found that alcohol had a profound effect on some, but not all, brain circuits activated in sober driving. The areas most profoundly affected by alcohol were the orbital frontal and anterior cingulate areas, which help control motor functions. The medial frontal regions of the brain involved in making decisions, and working memory, were not affected until the person was beyond the legal limit of intoxication. A function of working memory might be to find one's way home, the researchers said.

Keyword: Drug Abuse
Link ID: 6449 - Posted: 11.20.2004

Ben Harder An experimental diet drug looks like a long-distance success. New data indicate that obese adults who lose weight during a year of taking rimonabant and dieting keep the weight off during the following year, if they continue the regimen. The drug, which Paris-based manufacturer Sanofi-Aventis calls Acomplia, blocks cells' receptors for chemicals called cannabinoids, which include substances in marijuana. Some cravings for food and addictive substances depend on those receptors. Yearlong trials of rimonabant had suggested that the drug aids initial weight loss. But the real test of an obesity treatment is whether weight shed in one year stays away the next. So, endocrinologist F. Xavier Pi-Sunyer of Columbia University and his colleagues at 64 U.S. and 8 Canadian institutions enlisted more than 3,000 obese volunteers, mostly women, who agreed to take a daily pill while attempting to diet for 2 years. Throughout the study, investigators recorded the volunteers' weight, blood concentrations of cholesterols, and other indicators of metabolic health. During the first year, two-fifths of the volunteers took 20 milligrams per day of rimonabant, a similar number took 5 mg/day, and the rest took a placebo pill. Copyright ©2004 Science Service.

Keyword: Obesity
Link ID: 6448 - Posted: 06.24.2010

By DONALD G. McNEIL Jr. A possible new case of mad cow disease has been found in the United States, the Agriculture Department said yesterday. The agency said the brain of a cow tested positive three times on a rapid test for the presence of prions, the misfolded proteins that cause the disease. The department considers the rapid test inconclusive. The results await confirmation by more complex tests, and experts expect those to take four to seven days at the National Veterinary Services Laboratory in Ames, Iowa. A food safety expert who frequently criticizes the testing program said the results made it almost certain that the cow was infected. The expert, Dr. Michael K. Hansen, a senior research associate at Consumers Union, put the chances of an error at one in 100,000. Infected or not, the animal "did not enter the food or feed chain," said Dr. Andrea Morgan, associate deputy administrator of the Animal and Plant Health Inspection Service, part of the Agriculture Department. Copyright 2004 The New York Times Company

Keyword: Prions
Link ID: 6447 - Posted: 11.19.2004

By Simon Cox and Richard Vadon The tactics of a small hardcore of animal rights activists have brought them in confrontation with major corporations, scientific establishments and the government. Some of their strategies have appalled many people, especially those who have been targeted. Whether people support them or not, it cannot be denied that their tactics have had an impact. So what have been the key elements of their approach? The campaign waged against Huntingdon Life Sciences, Europe's largest vivisection laboratory, has shown the increasingly sophisticated tactics of the animal rights movement. The Stop Huntingdon Animal Cruelty (Shac) campaign has focused on the suppliers. So far this year 80 companies have severed ties with Huntingdon because of pressure from animal rights campaigners and fear of bad publicity. Greg Avery of the Shac campaign has found that many of the biggest companies can be persuaded very quickly and not because they care about animals. (C)BBC

Keyword: Animal Rights
Link ID: 6446 - Posted: 11.19.2004