Chapter 4. The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
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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
By Denali Tietjen Caffeine isn’t healthy, but that’s no news. The withdrawal headaches, jitteriness and dehydration kind of gave that one way. What is news, however, is that starting at puberty, it’s worse for boys than girls. Girls and boys have the same cardiovascular reactions to caffeine in childhood, but begin to react differently in adolescence, finds a new study conducted by researchers from The University of Buffalo. In the double-blind study published in the June issue of Pediatrics, researchers examined the cardiovascular reactions of 52 pre-pubescent (ages eight to nine) and 49 post-pubescent (ages 15 to 17) children to varying levels of caffeine. Participants consumed either the placebo, 1 mg/kg or 2 mg/kg caffeinated sodas, and then had their heart rates and blood pressures taken. The results found that pre-pubescent children had the same reaction to caffeine regardless of gender, while post-pubescent boys had much stronger cardiovascular reactions to caffeine than girls. The study also examined post-pubescent girls’ reactions to caffeine at various phases of their menstrual cycles. At different stages of the cycle, the girls metabolized caffeine differently. “We found differences in responses to caffeine across the menstrual cycle in post-pubertal girls, with decreases in heart rate that were greater in the mid-luteal phase and blood pressure increases that were greater in the mid-follicular phase of the menstrual cycle,” Dr. Jennifer Temple, one of the researchers who conducted the study said in a University at Buffalo press release announcing the study.
By Brian Palmer Maureen Dowd, a 62-year-old Pulitzer Prize–winning columnist for the New York Times, had a bad marijuana trip earlier this year. As part of her research into the legalization of recreational cannabis in Colorado, she ate a few too many bites of a pot-infused candy bar, entered a “hallucinatory state,” and spent eight paranoid hours curled up on her hotel room bed. Dowd used the experience as a jumping-off point to discuss the risks of overdosing on edible marijuana, which has become a major issue in pot-friendly states. It’s also possible, however, that Dowd just doesn’t handle cannabis very well. While pot mellows most people out, everyone has heard of someone who barricaded himself or herself in a dorm room after a few bongs hits in college. (Or maybe that someone is you.) Why do people react so differently to the same drug? The question itself may be something of a fallacy. Cannabis is not a single drug—it contains dozens of compounds, and they appear to have varying, and sometimes opposing, effects on the brain. Tetrahydrocannabinol, or THC, and cannabidiol, or CBD, have been the subject of some intriguing research. In 2010, researchers showed that pretreating people with a dose of CBD can protect against the less pleasant effects of THC, such as paranoia. In a similar 2012 study, participants took pills that contained only one of the two chemicals, rather than the combination that you receive in cannabis. The subjects who took THC pills were more likely to suffer paranoia and delusion than those who took CBD. The researchers went one step further to investigate which specific cognitive effects of THC are likely to lead to paranoia and other symptoms of psychosis. After taking either THC or CBD, participants watched a series of arrows appear on a screen and responded by indicating which direction the arrows were pointing. Most of the arrows pointed directly left or right, but occasionally a tilted arrow appeared. (Researchers called the tilted arrows “oddballs.”) Subjects who took the CBD had a heightened brain activity response to the oddballs. That’s the way a nondrugged person typically reacts—repetitions of the same stimulus don’t interest us, but a sudden change grabs our attention. The THC-takers had an abnormal response: They found the left and right arrows, which constituted the overwhelming majority of the images, more noteworthy than the oddballs. © 2014 The Slate Group LLC
By J. DAVID GOODMAN and ANEMONA HARTOCOLLIS Amid the weeknight bustle of a Walmart parking lot in Centereach, N.Y., a young woman in a pickup truck had lost consciousness and was turning blue. Her companion called 911. Possible drug overdose; come fast. A Suffolk County police officer, Matthew Siesto, who had been patrolling the lot, was the first to arrive. Needles were visible in the center console; the woman was breathing irregularly, and her pupils had narrowed to pinpoints. It seemed clear, Officer Siesto recalled of the October 2012 episode, that the woman had overdosed on heroin. He went back to his squad car and retrieved a small kit of naloxone, an anti-overdose medication he had only recently been trained to use in such circumstances. He prepared the dose, placed the atomizer in her nostril and sprayed. “Within a minute,” the officer said, “she came back.” Once the exclusive purview of paramedics and emergency room doctors, administering lifesaving medication to drug users in the throes of an overdose is quickly becoming an everyday part of police work amid a national epidemic of heroin and opioid pill abuse. On Wednesday, Gov. Andrew M. Cuomo committed state money to get naloxone into the hands of emergency medical workers across New York, saying the heroin epidemic in the state was worse than that seen in the 1970s, and the problem is growing. Last month, the New York police commissioner, William J. Bratton, announced that the city’s entire patrol force would soon be trained and equipped with naloxone. “Officers like it because it puts them in a lifesaving opportunity,” Mr. Bratton said, suggesting that beat officers would carry it on their belts. © 2014 The New York Times Company
Keyword: Drug Abuse
Link ID: 19728 - Posted: 06.14.2014
Nathan Greenslit A recent neuroscience study from Harvard Medical School claims to have discovered brain differences between people who smoke marijuana and people who do not. Such well-intentioned and seemingly objective science is actually a new chapter in a politicized and bigoted history of drug science in the United States. The study in question compared magnetic resonance imaging (MRI) scans of 20 “young adult recreational marijuana users” (defined as individuals 18 to 25 who smoke at least once a week but who are not “dependent”), to 20 “non-using controls” (age-matched individuals who have smoked marijuana less than five times in their lives). The researchers reported differences in density, volume, and shape between the nucleus accumbens and amygdala regions of the two groups’ brains—areas hypothesized to affect a wide range of emotions from happiness to fear, which could influence basic decision-making. Researchers did not make any claims about how marijuana affected actual emotions, cognition, or behavior in these groups; instead; the study merely tried to establish that the aggregated brain scans of the two groups look different. So, who cares? Different-looking brains tell us literally nothing about who these people are, what their lives are like, why they do or do not use marijuana, or what effects marijuana has had on them. Neither can we use such brain scans to predict who these people will become, or what their lives will be like in the future. Nonetheless the study invented two new categories of person: the “young casual marijuana user” and the young non-marijuana user. This is the latest example of turning to brain imaging to make something seem objective. Establishing brain differences among certain groups highlights the uniquely ignoble political history surrounding the criminalization of a plant. © 2014 by The Atlantic Monthly Group
Keyword: Drug Abuse
Link ID: 19725 - Posted: 06.14.2014
Claudia M. Gold Tom Insel, director of the National Institute of Mental Health (NIMH,) in his recent blog post "Are Children Overmedicated?" seems to suggest that perhaps more psychiatric medication is in order. Comparing mental illness in children to food allergies, he dismisses the "usual" explanations given for the increase medication prescribing patterns. In his view, these explanations are: Blaming psychiatrists who are too busy to provide therapy, parents who are too busy to provide a stable home environment, drug companies for marketing their products, and schools for lack of recess. By concluding that perhaps the explanation for the increase in prescribing of psychiatric medication to children is a greater number of children with serious psychiatric illness, Insel shows a lack of recognition of the complexity of the situation. When a recent New York Times article, that Insel makes reference to, reported on the rise in prescribing of psychiatric medication for toddlers diagnosed with ADHD, with a disproportionate number coming from families of poverty, one clinician remarked that if this is an attempt to medicate social and economic issues, then we have a huge problem. He was on to something. In conversations with pediatricians (the main prescribers of these medications) and child psychiatrists on the front lines, I find many in a reactive stance. When people feel overwhelmed, they go into survival mode, with their immediate aim just to get through the day. They find themselves prescribing medication because they have no other options.
A moderate dose of MDMA. commonly known as Ecstasy or Molly, that is typically nonfatal in cool, quiet environments can be lethal in rats exposed to conditions that mimic the hot, crowded, social settings where the drug is often used by people, a study finds. Scientists have identified the therapeutically-relevant cooling mechanism to enable effective interventions when faced with MDMA-induced hyperthermia. The study, publishing tomorrow in the Journal of Neuroscience, was conducted by researchers at the National Institute on Drug Abuse’s Intramural Research Program (NIDA IRP). NIDA is a part of the National Institutes of Health. While MDMA can have a range of adverse health effects, previous studies have shown that high doses of MDMA increase body temperature, while results with moderate doses were inconsistent. This has led some people to assume that the drug is harmless if taken in moderation. However, this study shows that in rats even moderate doses of MDMA in certain environments can be dangerous because it interferes with the body’s ability to regulate temperature. “We know that high doses of MDMA can sharply increase body temperature to potentially lead to organ failure or even death,” said NIDA Director Dr. Nora D. Volkow. “However, this current study opens the possibility that even moderate doses could be deadly in certain conditions.” It is impossible to predict who will have an adverse reaction even to a low dose of MDMA. However, in this study scientists gave the rats low to moderate doses that have been shown in past studies to not be fatal. They monitored the rats to determine drug-induced changes in brain and body temperature and in the body’s ability to cool itself through blood vessel dilation. When rats were alone and in a room-temperature environment, a moderate dose of MDMA modestly increased brain and body temperature and moderately diminished the rats’ ability to eliminate excessive heat. However, when researchers injected the same dose in rats that were either in a warmer environment or in the presence of another rat in the cage, brain temperature increased, causing death in some rats. These fatal temperature increases were because the drug interfered with the body’s ability to eliminate heat.
Keyword: Drug Abuse
Link ID: 19695 - Posted: 06.05.2014
Sarah C. P. Williams This, in all its molecular complexity, is what the bulging end of a single neuron looks like. A whopping 300,000 proteins come together to form the structure, which is less than a micrometer wide, hundreds of times smaller than a grain of sand. This particular synapse is from a rat brain. It’s where chemical signals called neurotransmitters are released into the space between neurons to pass messages from cell to cell. To create a 3D molecular model of the structure, researchers first isolated the synapses of rat neurons and turned to classic biochemistry to identify and quantify the molecules present at every stage of the neurotransmitter release cycle. Then, they used microscopy to pinpoint the location of each protein. Some proteins—like the red patches of SNAP25 visible in the video at 0:14—aid in the release of vesicles, tiny spheres full of neurotransmitters. Others—like the green, purple, and red rods at 0:45—help the synapse maintain its overall structure. Different proteins surround vesicles when they’re inside the synapse—the circles scattered throughout the structure at 0:56—than when the vesicles are forming at the edge of the synapse—as shown at 2:08. Researchers can use the model, described online today in Science, to better understand how neurons function and what goes wrong in brain disorders. (Video credit: Wilhelm et al. 2014, Science) © 2014 American Association for the Advancement of Science.
Keyword: Brain imaging
Link ID: 19678 - Posted: 05.31.2014