Chapter 4. The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
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by Bethany Brookshire Every day sees a new research article on addiction, be it cocaine, heroin, food or porn. Each one takes a specific angle on how addiction works in the brain. Perhaps it’s a disorder of reward, with drugs hijacking a natural system that is meant to respond to food, sex and friendship. Possibly addiction is a disorder of learning, where our brains learn bad habits and responses. Maybe we should think of addiction as a combination of an environmental stimulus and vulnerable genes. Or perhaps it’s an inappropriate response to stress, where bad days trigger a relapse to the cigarette, syringe or bottle. None of these views are wrong. But none of them are complete, either. Addiction is a disorder of reward, a disorder of learning. It has genetic, epigenetic and environmental influences. It is all of that and more. Addiction is a display of the brain’s astounding ability to change — a feature called plasticity — and it showcases what we know and don’t yet know about how brains adapt to all that we throw at them. “A lot of people think addiction is what happens when someone finds a drug to be the most rewarding thing they’ve ever experienced,” says neuroscientist George Koob, director of the National Institute on Alcohol Abuse and Alcoholism in Bethesda, Md. “But drug abuse is not just feeling good about drugs. Your brain is changed when you misuse drugs. It is changed in ways that perpetuate the problem.” The changes associated with drug use affect how addicts respond to drug cues, like the smell of a cigarette or the sight of a shot of vodka. Drug abuse also changes how other rewards, such as money or food are processed, decreasing their relative value. © Society for Science & the Public 2000 - 2013
By PHILIP M. BOFFEY For Michele Leonhart, the administrator of the Drug Enforcement Administration, there is no difference between the health effects of marijuana and those of any other illegal drug. “All illegal drugs are bad for people,” she told Congress in 2012, refusing to say whether crack, methamphetamines or prescription painkillers are more addictive or physically harmful than marijuana. Her testimony neatly illustrates the vast gap between antiquated federal law enforcement policies and the clear consensus of science that marijuana is far less harmful to human health than most other banned drugs and is less dangerous than the highly addictive but perfectly legal substances known as alcohol and tobacco. Marijuana cannot lead to a fatal overdose. There is little evidence that it causes cancer. Its addictive properties, while present, are low, and the myth that it leads users to more powerful drugs has long since been disproved. That doesn’t mean marijuana is harmless; in fact, the potency of current strains may shock those who haven’t tried it for decades, particularly when ingested as food. It can produce a serious dependency, and constant use would interfere with job and school performance. It needs to be kept out of the hands of minors. But, on balance, its downsides are not reasons to impose criminal penalties on its possession, particularly not in a society that permits nicotine use and celebrates drinking. Marijuana’s negative health effects are arguments for the same strong regulation that has been effective in curbing abuse of legal substances. Science and government have learned a great deal, for example, about how to keep alcohol out of the hands of minors. Mandatory underage drinking laws and effective marketing campaigns have reduced underage alcohol use to 24.8 percent in 2011, compared with 33.4 percent in 1991. Cigarette use among high school students is at its lowest point ever, largely thanks to tobacco taxes and growing municipal smoking limits. There is already some early evidence that regulation would also help combat teen marijuana use, which fell after Colorado began broadly regulating medical marijuana in 2010. © 2014 The New York Times Company
Keyword: Drug Abuse
Link ID: 19909 - Posted: 08.02.2014
By BRENT STAPLES The federal law that makes possession of marijuana a crime has its origins in legislation that was passed in an atmosphere of hysteria during the 1930s and that was firmly rooted in prejudices against Mexican immigrants and African-Americans, who were associated with marijuana use at the time. This racially freighted history lives on in current federal policy, which is so driven by myth and propaganda that it is almost impervious to reason. The cannabis plant, also known as hemp, was widely grown in the United States for use in fabric during the mid-19th century. The practice of smoking it appeared in Texas border towns around 1900, brought by Mexican immigrants who cultivated cannabis as an intoxicant and for medicinal purposes as they had done at home. Within 15 years or so, it was plentiful along the Texas border and was advertised openly at grocery markets and drugstores, some of which shipped small packets by mail to customers in other states. The law enforcement view of marijuana was indelibly shaped by the fact that it was initially connected to brown people from Mexico and subsequently with black and poor communities in this country. Police in Texas border towns demonized the plant in racial terms as the drug of “immoral” populations who were promptly labeled “fiends.” As the legal scholars Richard Bonnie and Charles Whitebread explain in their authoritative history, “The Marihuana Conviction,” the drug’s popularity among minorities and other groups practically ensured that it would be classified as a “narcotic,” attributed with addictive qualities it did not have, and set alongside far more dangerous drugs like heroin and morphine. © 2014 The New York Times Company
Keyword: Drug Abuse
Link ID: 19903 - Posted: 07.31.2014
By Marek Kohn “You know how they say that we can only access 20% of our brain?” says the man who offers stressed-out writer Eddie Morra a fateful pill in the 2011 film Limitless. “Well, what this does, it lets you access all of it.” Morra is instantly transformed into a superhuman by the fictitious drug NZT-48. Granted access to all cognitive areas, he learns to play the piano in three days, finishes writing his book in four, and swiftly makes himself a millionaire. Limitless is what you get when you flatter yourself that your head houses the most complex known object in the universe, and you run away with the notion that it must have powers to match. A number of so-called ‘smart drugs’ or cognitive enhancers have captured attention recently, from stimulants such as modafinil, to amphetamines (often prescribed under the name Adderall) and methylphenidate (also known by its brand name Ritalin). According to widespread news reports, students have begun using these drugs to enhance their performance in school and college, and are continuing to do so in their professional lives. Yet are these smart drugs all they are cracked up to be? Can they really make all of us more intelligent or learn more? Should we be asking deeper questions about what these pharmaceuticals can and can’t do? BBC © 2014
by Helen Thomson How do you smell after a drink? Quite well, it turns out. A modest amount of alcohol boosts your sense of smell. It is well known that we can improve our sense of smell through practice. But a few people have also experienced a boost after drug use or brain damage. This suggests our sensitivity to smell may be damped by some sort of inhibition in the brain, which can be lifted under some circumstances, says Yaara Endevelt of the Weizmann Institute of Science in Rehovot, Israel. To explore this notion, Endevelt and her colleagues investigated whether drinking alcohol – known to lower inhibitory signals in the brain – affected the sense of smell. In one odour-discrimination test, 20 volunteers were asked to smell three different liquids. Two were a mixture of the same six odours, the third contained a similar mixture with one odour replaced. Each volunteer was given 2 seconds to smell each of the liquids and say which was the odd one out. The test was repeated six times with each of three trios of liquids. They were then given a drink that consisted of 35 millilitres of vodka and sweetened grape juice, or the juice alone, before repeating the experiment with the same set of liquids. In a second experiment with a similar drinking structure, the same volunteers were asked which of three liquids had a rose-like odour. The researchers increased the concentration of the odour until the volunteers got the right answer three times in a row. © Copyright Reed Business Information Ltd.
Keyword: Chemical Senses (Smell & Taste)
Link ID: 19875 - Posted: 07.24.2014
By ANN SANNER Associated Press COLUMBUS, Ohio (AP) — A few weeks before their prom king’s death, students at an Ohio high school had attended an assembly on narcotics that warned about the dangers of heroin and prescription painkillers. But it was one of the world’s most widely accepted drugs that killed Logan Stiner — a powdered form of caffeine so potent that as little as a single teaspoon can be fatal. The teen’s sudden death in May has focused attention on the unregulated powder and drawn a warning from federal health authorities urging consumers to avoid it. ‘‘I don’t think any of us really knew that this stuff was out there,’’ said Jay Arbaugh, superintendent of the Keystone Local Schools. The federal Food and Drug Administration said Friday that it’s investigating caffeine powder and will consider taking regulatory action. The agency cautioned parents that young people could be drawn to it. An autopsy found that Stiner had a lethal amount of caffeine in his system when he died May 27 at his home in LaGrange, Ohio, southwest of Cleveland. Stiner, a wrestler, had more than 70 micrograms of caffeine per milliliter of blood in his system, as much as 23 times the amount found in a typical coffee or soda drinker, according to the county coroner. His mother has said she was unaware her son took caffeine powder. He was just days away from graduation and had planned to study at the University of Toledo. Caffeine powder is sold as a dietary supplement, so it’s not subject to the same federal regulations as certain caffeinated foods. Users add it to drinks for a pick-me-up before workouts or to control weight gain. A mere 1/16th of a teaspoon can contain about 200 milligrams of caffeine, roughly the equivalent of two large cups of coffee. That means a heaping teaspoon could kill, said Dr. Robert Glatter, an emergency physician at Lenox Hill ?Hospital in New York.
Keyword: Drug Abuse
Link ID: 19857 - Posted: 07.21.2014
By Lizzie Wade This week, a team from the National Institute on Drug Abuse (NIDA) reported that heavy marijuana use may damage the brain's pleasure center. Meanwhile, researchers in the United Kingdom say they’ve figured out why pot makes you paranoid. But does focusing research on cannabis’s “bad side” give the drug short shrift? Science talked to Ian Mitchell, an emergency physician at the University of British Columbia’s Southern Medical Program in Kamloops, Canada, and author of the blog Clinical Cannabis in Context, who says that politics influences research in this controversial field. As a doctor who recommends medical cannabis to patients, he follows research on the drug and often critiques studies he believes are based on outdated information or were performed with an anticannabis bias. This interview has been edited for clarity and brevity. Q: What do you think of the NIDA study? A: They said they gave marijuana abusers Ritalin and nothing happened. One of the ways you could interpret that is, OK, these pleasure centers are damaged. But you could also say, perhaps marijuana decreases the effects of [Ritalin] on people. That would be equally as right an interpretation. Q: Why do we hear more about studies that show negative effects of marijuana? A: NIDA is at the center of cannabis research in America. And their mandate, very plainly, is to study drug abuse. So they overwhelmingly fund studies that look at abuse. In America, if you wanted to run a study that showed a benefit of cannabis, you weren’t allowed to do that because NIDA couldn’t give you samples to use. So there were no trials [on potential medical benefits] being done. For example, there hasn’t been a good trial yet to study marijuana’s potential for treating posttraumatic stress disorder. They couldn’t get it done, due to all these political roadblocks. © 2014 American Association for the Advancement of Science
By Lizzie Wade It probably won’t come as a surprise that smoking a joint now and then will leave you feeling … pretty good, man. But smoking a lot of marijuana over a long time might do just the opposite. Scientists have found that the brains of pot abusers react less strongly to the chemical dopamine, which is responsible for creating feelings of pleasure and reward. Their blunted dopamine responses could leave heavy marijuana users living in a fog—and not the good kind. After high-profile legalizations in Colorado, Washington, and Uruguay, marijuana is becoming more and more available in many parts of the world. Still, scientific research on the drug has lagged. Pot contains lots of different chemicals, and scientists don’t fully understand how those components interact to produce the unique effects of different strains. Its illicit status in most of the world has also thrown up barriers to research. In the United States, for example, any study involving marijuana requires approval from four different federal agencies, including the Drug Enforcement Administration. One of the unanswered questions about the drug is what, exactly, it does to our brains, both during the high and afterward. Of particular interest to scientists is marijuana’s effect on dopamine, a main ingredient in the brain’s reward system. Pleasurable activities such as eating, sex, and some drugs all trigger bursts of dopamine, essentially telling the brain, “Hey, that was great—let’s do it again soon.” Scientists know that drug abuse can wreak havoc on the dopamine system. Cocaine and alcohol abusers, for example, are known to produce far less dopamine in their brains than people who aren’t addicted to those drugs. But past studies had hinted that the same might not be true for those who abuse marijuana. © 2014 American Association for the Advancement of Science
Keyword: Drug Abuse
Link ID: 19832 - Posted: 07.15.2014
|By Maria Burke and ChemistryWorld The world needs to tackle head-on the market failures undermining dementia research and drug development, UK Prime Minister David Cameron told a summit of world health and finance leaders in London in June. He announced an investigation into how to get medicines to patients earlier, extend patents and facilitate research collaborations, to report this autumn. But just how much difference will these sorts of measures make when scientists are still grappling with exactly what causes different types of dementia? Added to these problems is that dementia has become a graveyard for a large number of promising drugs. A recent study looked at how 244 compounds in 413 clinical trials fared for Alzheimer's disease between 2002 and 2012. The researchers findings paint a gloomy picture. Of those 244 compounds, only one was approved. The researchers report that this gives Alzheimer's disease drug candidates one of the highest failures rates of any disease area – 99.6%, compared with 81% for cancer. ‘Dementia is a ticking bomb costing the global economy £350 billion and yet progress with research is achingly slow,’ warned the World Dementia Envoy, Dennis Gillings. Businesses need incentives to invest in research and bring in faster, cheaper clinical trials, or the world won’t meet the ambition to find a cure or disease-modifying therapy by 2025, he added. ‘We need to free up regulation so that we can test ground-breaking new drugs, and examine whether the period for market exclusivity could be extended.’ © 2014 Scientific American
Link ID: 19828 - Posted: 07.15.2014
By Jules Wellinghoff A simple change in electric charge may make the difference between someone getting the medicine they need and a trip to the emergency room—at least if a new study bears out. Researchers investigating the toxicity of particles designed to ferry drugs inside the body have found that carriers with a positive charge on their surface appear to cause damage if they reach the brain. These particles, called micelles, are one type of a class of materials known as nanoparticles. By varying properties such as charge, composition, and attached surface molecules, researchers can design nanoparticles to deliver medicine to specific body regions and cell types—and even to carry medicine into cells. This ability allows drugs to directly target locations they would otherwise be unable to, such as the heart of tumors. Researchers are also looking at nanoparticles as a way to transport drugs across the blood-brain barrier, a wall of tightly connected cells that keeps most medication out of the brain. Just how safe nanoparticles in the brain are, however, remains unclear. So Kristina Bram Knudsen, a toxicologist at the National Research Centre for the Working Environment in Copenhagen, and colleagues tested two types of micelles, which were made from different polymers that gave the micelles either a positive or negative surface charge. They injected both versions, empty of drugs, into the brains of rats, and 1 week later they checked for damage. Three out of the five rats injected with the positively charged micelles developed brain lesions. The rats injected with the negatively charged micelles or a saline control solution did not suffer any observable harm from the injections, the team will report in an upcoming issue of Nanotoxicology. © 2014 American Association for the Advancement of Science
Link ID: 19819 - Posted: 07.12.2014
By JOSHUA A. KRISCH Excessive alcohol consumption, including binge drinking, is responsible for 10 percent of deaths among working-age adults in the United States, according to a recent study from the Centers for Disease Control and Prevention. The researchers used an online tool called the Alcohol-Related Disease Impact application to estimate alcohol-related deaths ranging from car crashes and alcohol poisoning to liver and heart disease. They defined binge drinking as at least five consecutive drinks for men and four consecutive drinks for women. One in six adults from 20 to 65 reported binge drinking at least four times a month; the actual number is likely higher because subjects tend to underreport their drinking habits, the researchers said. The number of Americans who binge drink skyrocketed during the 1990s and leveled off in 2001, but the average frequency of binge drinking episodes is still rising. Excessive drinking is the fourth leading cause of preventable death in the United States, after smoking, poor nutrition and physical inactivity. “It’s a huge public health problem any way you slice it,” said Robert D. Brewer, a co-author of the paper and the director of the alcohol program at the C.D.C.“There are things that we can do about it,” like raising the alcohol tax and encouraging doctors to talk to their patients about alcohol abuse, “but a lot of those strategies tend to be underused.” © 2014 The New York Times Company
Keyword: Drug Abuse
Link ID: 19799 - Posted: 07.08.2014
By GABRIELLE GLASER When their son had to take a medical leave from college, Jack and Wendy knew they — and he — needed help with his binge drinking. Their son’s psychiatrist, along with a few friends, suggested Alcoholics Anonymous. He had a disease, and in order to stay alive, he’d have to attend A.A. meetings and abstain from alcohol for the rest of his life, they said. But the couple, a Manhattan reporter and editor who asked to be identified only by their first names to protect their son’s privacy, resisted that approach. Instead, they turned to a group of psychologists who specialize in treating substance use and other compulsive behaviors at the Center for Motivation and Change. The center, known as the C.M.C., operates out of two floors of a 19th-century building on 30th Street and Fifth Avenue. It is part of a growing wing of addiction treatment that rejects the A.A. model of strict abstinence as the sole form of recovery for alcohol and drug users. Instead, it uses a suite of techniques that provide a hands-on, practical approach to solving emotional and behavioral problems, rather than having abusers forever swear off the substance — a particularly difficult step for young people to take. And unlike programs like Al-Anon, A.A.’s offshoot for family members, the C.M.C.’s approach does not advocate interventions or disengaging from someone who is drinking or using drugs. “The traditional language often sets parents up to feel they have to make extreme choices: Either force them into rehab or detach until they hit rock bottom,” said Carrie Wilkens, a psychologist who helped found the C.M.C. 10 years ago. “Science tells us those formulas don’t work very well.” When parents issue edicts, demanding an immediate end to all substance use, it often lodges the family in a harmful cycle, said Nicole Kosanke, a psychologist at the C.M.C. Tough love might look like an appropriate response, she said, but it often backfires by further damaging the frayed connections to the people to whom the child is closest. © 2014 The New York Times Company
Keyword: Drug Abuse
Link ID: 19794 - Posted: 07.04.2014
Claire McCarthy I have many patients with ADHD (Attention Deficit Hyperactivity Disorder) and it seems like I have the same conversation over and over again with their parents: to medicate or not to medicate. I completely understand the hesitation I hear from so many parents. I have to admit, I'm not entirely happy myself about prescribing a medication that has side effects and can be abused or misused, and one for which there is a black market. I also worry that too often when a child is on medication and so learning and behaving better, parents and teachers lose the incentive to help the child learn the organizational and other skills that could make all the difference later in life. Since ADHD often persists into adulthood, we have to have the long view with these kids. But....the long view works the other way, too. Not treating ADHD with medication can lead to problems. Like drug abuse. ADHD is really common. It affects 8 percent of children and youth--that's about 2 in every classroom of 20. Kids with ADHD can have real problems with both learning and behavior, problems that can haunt them for a lifetime (if you end up dropping out of high school because of poor grades or behavior, or end up getting arrested, it has a way of interfering with your future income and quality of life). But another thing we know is that kids with ADHD have a higher risk of drug abuse. We don't know exactly why this is the case. Some of it is likely the impulsivity that is so common in people with ADHD; they don't always make the best decisions. It may also be that people with ADHD are more prone to addiction. Whatever it is, the risk is very real. Not only are kids with ADHD 2.5 times more likely to abuse drugs, they are more likely to start earlier, use more types of drugs, and continue into adulthood. ©2014 Boston Globe Media Partners, LLC
A toxic caffeine level was found in the system of a high school student who died unexpectedly, says a U.S. coroner who warns young people need to be educated about the dangers of taking the potent powder that is sold online. Logan Stiner, 18, was found dead at his family’s home in May. Steiner was an excellent student and a healthy young man who didn’t do drugs, Dr. Stephen Evans, a coroner in Lorain County, Ohio, said Monday. "We sent his blood out for levels, and [when] it came back it was a toxic level. Caffeine toxicity will do exactly what happened to him. It'll lead to things like cardiac arrhytmias and seizures," Evans said in an interview. Use of caffeine from coffee, tea and other beverages is so widespread that it is considered innocuous, but that’s not the case when it’s taken in an overdose amount. Powdered caffeine is sold in bulk over the internet. Problems can arise because adding a teaspoon of the caffeine powder to water is the equivalent of 30 cups of coffee. About one-sixteenth of a teaspoon of the powder is equal to about two cups of coffee. Evans said he recognizes that weightlifters will say Stiner should’ve taken the correct amount. "One-sixteenth of a teaspoon. You expect a kid to figure that out?" He suggested that regulators re-consider internet sales of a pound of powdered caffeine to young people. When Evans and his staff reviewed the pathology literature, they found 18 other cases of deaths in the U.S. from caffeine overdoses. Some were suicides and others were accidental, but he suspects the deaths are underreported since few pathologists investigating deaths from seizure and cardiac arrhytmia check caffeine levels. © CBC 2014
Emotional and behavioral problems show up even with low exposure to lead, and as blood lead levels increase in children, so do the problems, according to research funded by the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health. The results were published online June 30 in the journal JAMA Pediatrics. “This research focused on lower blood lead levels than most other studies and adds more evidence that there is no safe lead level,” explained NIEHS Health Scientist Administrator Kimberly Gray, Ph.D. “It is important to continue to study lead exposure in children around the world, and to fully understand short-term and long-term behavioral changes across developmental milestones. It is well-documented that lead exposure lowers the IQ of children.” Blood lead concentrations measured in more than 1,300 preschool children in China were associated with increased risk of behavioral and emotional problems, such as being anxious, depressed, or aggressive. The average blood lead level in the children was 6.4 micrograms per deciliter. While many studies to date have examined health effects at or above 10 micrograms per deciliter, this study focused on lower levels. The CDC now uses a reference level of 5 micrograms per deciliter, to identify children with blood lead levels that are much higher than normal, and recommends educating parents on reducing sources of lead in their environment and continued monitoring of blood lead levels.
|By Lindsey Konkel and Environmental Health News Babies whose moms lived within a mile of crops treated with widely used pesticides were more likely to develop autism, according to new research. The study of 970 children, born in farm-rich areas of Northern California, is part of the largest project to date that is exploring links between autism and environmental exposures. The University of California, Davis research – which used women’s addresses to determine their proximity to insecticide-treated fields – is the third project to link prenatal pesticide exposures to autism and related disorders. “The weight of evidence is beginning to suggest that mothers’ exposures during pregnancy may play a role in the development of autism spectrum disorders,” said Kim Harley, an environmental health researcher at the University of California, Berkeley who was not involved in the new study. One in every 68 U.S. children has been identified with an autism spectrum disorder—a group of neurodevelopmental disorders characterized by difficulties with social interactions, according to the Centers for Disease Control and Prevention. “This study does not show that pesticides are likely to cause autism, though it suggests that exposure to farming chemicals during pregnancy is probably not a good thing,” said Dr. Bennett Leventhal, a child psychiatrist at University of California, San Francisco who studies autistic children. He did not participate in the new study. The biggest known contributor to autism risk is having a family member with it. Siblings of a child with autism are 35 times more likely to develop it than those without an autistic brother or sister, according to the National Institutes of Health. © 2014 Scientific American
Heidi Ledford If shown to be possible in humans, addiction to the Sun could help explain why some tanners continue to seek out sunlight despite being well aware of the risks. The lure of a sunny day at the beach may be more than merely the promise of fun and relaxation. A study published today reports that mice exposed to ultraviolet (UV) rays exhibit behaviours akin to addiction. The researchers found that mice exposed repeatedly to UV light produced an opioid called β-endorphin, which numbs pain and is associated with addiction to drugs. When they were given a drug that blocks the effect of opioids, the mice also showed signs of withdrawal — including shaky paws and chattering teeth. If the results hold true in humans, they would suggest an explanation for why many tanners continue to seek out sunlight, despite the risks — and, in some cases, even after being diagnosed with skin cancer. “This offers a clear potential mechanism for how UV radiation can be rewarding and, in turn, potentially addictive,” says Bryon Adinoff, an addiction psychiatrist at the University of Texas Southwestern Medical Center in Dallas, who was not involved with the study. “That’s a big deal.” Oncologist David Fisher of the Massachusetts General Hospital in Boston and his colleagues became interested in sunlight addiction after studying the molecular mechanisms of pigment production in the skin after UV light exposure. In the new study published today in Cell1, they show that in mice, some skin cells also synthesize β-endorphin in response to chronic, low doses of UV light. © 2014 Nature Publishing Group
Keyword: Drug Abuse
Link ID: 19752 - Posted: 06.21.2014
By Robert Dudley When we think about the origins of agriculture and crop domestication, alcohol isn’t necessarily the first thing that comes to mind. But our forebears may well have been intentionally fermenting fruits and grains in parallel with the first Neolithic experiments in plant cultivation. Ethyl alcohol, the product of fermentation, is an attractive and psychoactively powerful inebriant, but fermentation is also a useful means of preserving food and of enhancing its digestibility. The presence of alcohol prolongs the edibility window of fruits and gruels, and can thus serve as a means of short-term storage for various starchy products. And if the right kinds of bacteria are also present, fermentation will stabilize certain foodstuffs (think cheese, yogurt, sauerkraut, and kimchi, for example). Whoever first came up with the idea of controlling the natural yeast-based process of fermentation was clearly on to a good thing. Using spectroscopic analysis of chemical residues found in ceramic vessels unearthed by archaeologists, scientists know that the earliest evidence for intentional fermentation dates to about 7000 BCE. But if we look deeper into our evolutionary past, alcohol was a component of our ancestral primate diet for millions of years. In my new book, The Drunken Monkey, I suggest that alcohol vapors and the flavors produced by fermentation stimulate modern humans because of our ancient tendencies to seek out and consume ripe, sugar-rich, and alcohol-containing fruits. Alcohol is present because of particular strains of yeasts that ferment sugars, and this process is most common in the tropics where fruit-eating primates originated and today remain most diverse. © 1986-2014 The Scientist
By Elizabeth Norton A single dose of a century-old drug has eliminated autism symptoms in adult mice with an experimental form of the disorder. Originally developed to treat African sleeping sickness, the compound, called suramin, quells a heightened stress response in neurons that researchers believe may underlie some traits of autism. The finding raises the hope that some hallmarks of the disorder may not be permanent, but could be correctable even in adulthood. That hope is bolstered by reports from parents who describe their autistic children as being caught behind a veil. "Sometimes the veil parts, and the children are able to speak and play more normally and use words that didn't seem to be there before, if only for a short time during a fever or other stress" says Robert Naviaux, a geneticist at the University of California, San Diego, who specializes in metabolic disorders. Research also shows that the veil can be parted. In 2007, scientists found that 83% of children with autism disorders showed temporary improvement during a high fever. The timing of a fever is crucial, however: A fever in the mother can confer a higher risk for the disorder in the unborn child. As a specialist in the cell's life-sustaining metabolic processes, Naviaux was intrigued. Autism is generally thought to result from scrambled signals at synapses, the points of contact between nerve cells. But given the specific effects of something as general as a fever, Naviaux wondered if the problem lay "higher up" in the cell's metabolism. © 2014 American Association for the Advancement of Science.
Link ID: 19749 - Posted: 06.19.2014
by Helen Thomson KULLERVO HYNYNEN is preparing to cross neuroscience's final frontier. In July he will work with a team of doctors in the first attempt to open the blood-brain barrier in humans – the protective layer around blood vessels that shields our most precious organ against threats from the outside world. If successful, the method would be a huge step in the treatment of pernicious brain diseases such as cancer, Parkinson's and Alzheimer's, by allowing drugs to pass into the brain. The blood-brain barrier (BBB) keeps toxins in the bloodstream away from the brain. It consists of a tightly packed layer of endothelial cells that wrap around every blood vessel throughout the brain. It prevents viruses, bacteria and any other toxins passing into the brain, while simultaneously ushering in vital molecules such as glucose via specialised transport mechanisms. The downside of this is that the BBB also completely blocks the vast majority of drugs. Exceptions include some classes of fat and lipid-soluble chemicals, but these aren't much help as such drugs penetrate every cell in the body – resulting in major side effects. "Opening the barrier is really of huge importance. It is probably the major limitation for innovative drug development for neurosciences," says Bart De Strooper, co-director of the Leuven Institute for Neuroscience and Disease in Belgium. © Copyright Reed Business Information Ltd.
Link ID: 19748 - Posted: 06.19.2014