1. Study suggests smartphone addiction creates imbalance in brain

    December 10, 2017 by Ashley

    From the Radiological Society of North America press release:

    Researchers have found an imbalance in the brain chemistry of young people addicted to smartphones and the internet, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA).


  2. Study suggests neuron-pruning drug may nudge mice away from habit-driven behaviors when combined with retraining

    by Ashley

    From the Emory Health Sciences press release:

    A drug that stimulates neuron pruning can nudge mice away from habit-driven behaviors when combined with retraining, neuroscientists have found.

    The results were published online on November 30 by Nature Communications.

    The drug fasudil, approved in Japan for cerebral vasospasm and stroke, inhibits an enzyme that stabilizes cells’ internal skeletons. The researchers suggest that fasudil or similar compounds could be effective tools for facilitating the treatment of drug abuse and preventing relapse.

    A large fraction of the actions people perform each day come from habits, not from deliberate decision making. Going on auto-pilot can free up attention for new things, but it can also be detrimental, in the case of drug abuse and drug-seeking behavior, says lead author Shannon Gourley, PhD, assistant professor of pediatrics, psychiatry and behavioral sciences at Emory University School of Medicine and Yerkes National Primate Research Center.

    “Some habits are adaptive — for example, turning off a light when you exit a room — but others can be maladaptive, for example in the case of habitual drug use. We wanted to try to figure out a way to help ‘break’ habits, particularly those related to the highly-addictive drug cocaine,” says Gourley.

    Gourley and former graduate students Andrew Swanson, PhD and Lauren Depoy, PhD tested fasudil in situations where they had trained mice to poke their noses in two chambers, based on rewards of both food and cocaine. Then the researchers changed the rules of the game. The mice had to learn something new, in terms of where to poke their noses to get the reward.

    In particular, the mice could now only get a reward from one chamber instead of both. Fasudil helped the mice adjust and display “goal-directed” behavior, rather than their previous habit-based behavior.

    In addition, the researchers trained the mice to supply themselves a sweet cocaine solution. Then they changed the nature of that experience: the cocaine was paired with lithium chloride, which made the mice feel sick. Fasudil treatment nudged the mice to give themselves less cocaine afterwards, rather than continuing to respond habitually. The scientists envision this as modeling negative experiences associated with cocaine use in humans.

    “Humans may seek treatment due to the negative consequences of cocaine abuse, but many people still relapse. We’re trying to strengthen the goal of abstaining from drug taking,” says Gourley.

    The researchers conducted additional experiments that revealed that fasudil didn’t make cocaine itself less pleasurable, but was specifically modifying the habit process. Also, fasudil did not affect other forms of decision making.

    Un-learning of habits involves remodeling connections made by cells in the brain. In the mouse retraining experiments, the way that fasudil seems to work is that it promotes the pruning of dendritic spines. Dendritic spines are structures that help neurons communicate and embody the strength of connections between them.

    Fasudil inhibits Rho kinase, which stabilizes F-actin, a major component of cells’ internal skeletons. Thus, it loosens up cell structures. And in mice, fasudil appears to slightly reduce the density of dendritic spines in a region of the brain that is important for learning new behaviors.

    “In this context, we imagine that fasudil is optimizing signal-to-noise, so to speak, allowing this brain region to efficiently guide decision making,” says Gourley.

    When fasudil is given to the mice a day after training, no changes in spine density are seen, indicating that it must be paired with new learning to have that effect.

    Some caution is order, because overactive synaptic pruning is proposed to play roles in Alzheimer’s disease and schizophrenia. In their paper, the authors conclude:

    Pairing Rho kinase inhibitors with cognitive behavioral therapy in humans could be an effective pharmacological adjunct to reduce the rate of relapse… Given its favorable safety profile and our evidence that it can mitigate cocaine self-administration, fasudil is a strong candidate, with the caveats that we envision it administered as an adjunct to behavioral therapy and potentially during early phases of drug withdrawal.


  3. Study suggests smartphone addiction creates imbalance in brain

    December 6, 2017 by Ashley

    From the Radiological Society of North America press release:

    Researchers have found an imbalance in the brain chemistry of young people addicted to smartphones and the internet, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA).

    According to a recent Pew Research Center study, 46 percent of Americans say they could not live without their smartphones. While this sentiment is clearly hyperbole, more and more people are becoming increasingly dependent on smartphones and other portable electronic devices for news, information, games, and even the occasional phone call.

    Along with a growing concern that young people, in particular, may be spending too much time staring into their phones instead of interacting with others, come questions as to the immediate effects on the brain and the possible long-term consequences of such habits.

    Hyung Suk Seo, M.D., professor of neuroradiology at Korea University in Seoul, South Korea, and colleagues used magnetic resonance spectroscopy (MRS) to gain unique insight into the brains of smartphone- and internet-addicted teenagers. MRS is a type of MRI that measures the brain’s chemical composition.

    The study involved 19 young people (mean age 15.5, 9 males) diagnosed with internet or smartphone addiction and 19 gender- and age-matched healthy controls. Twelve of the addicted youth received nine weeks of cognitive behavioral therapy, modified from a cognitive therapy program for gaming addiction, as part of the study.

    Researchers used standardized internet and smartphone addiction tests to measure the severity of internet addiction. Questions focused on the extent to which internet and smartphone use affects daily routines, social life, productivity, sleeping patterns and feelings.

    “The higher the score, the more severe the addiction,” Dr. Seo said.

    Dr. Seo reported that the addicted teenagers had significantly higher scores in depression, anxiety, insomnia severity and impulsivity.

    The researchers performed MRS exams on the addicted youth prior to and following behavioral therapy and a single MRS study on the control patients to measure levels of gamma aminobutyric acid, or GABA, a neurotransmitter in the brain that inhibits or slows down brain signals, and glutamate-glutamine (Glx), a neurotransmitter that causes neurons to become more electrically excited. Previous studies have found GABA to be involved in vision and motor control and the regulation of various brain functions, including anxiety.

    The results of the MRS revealed that, compared to the healthy controls, the ratio of GABA to Glx was significantly increased in the anterior cingulate cortex of smartphone- and internet-addicted youth prior to therapy.

    Dr. Seo said the ratios of GABA to creatine and GABA to glutamate were significantly correlated to clinical scales of internet and smartphone addictions, depression and anxiety.

    Having too much GABA can result in a number of side effects, including drowsiness and anxiety.

    More study is needed to understand the clinical implications of the findings, but Dr. Seo believes that increased GABA in the anterior cingulate gyrus in internet and smartphone addiction may be related to the functional loss of integration and regulation of processing in the cognitive and emotional neural network.

    The good news is GABA to Glx ratios in the addicted youth significantly decreased or normalized after cognitive behavioral therapy.

    “The increased GABA levels and disrupted balance between GABA and glutamate in the anterior cingulate cortex may contribute to our understanding the pathophysiology of and treatment for addictions,” Dr. Seo said.


  4. Rodent model of addiction challenges traditional view of how addiction is sustained

    December 1, 2017 by Ashley

    From the Society for Neuroscience press release:

    Drug addiction may not require a habitual relationship with a substance, suggests findings from a new model of cocaine administration in rats that better captures the human experience of obtaining and using drugs. The research, published in JNeurosci, represents a step towards a translational animal model of addiction that challenges widely held views about drug users.

    Much of what we know about the neurobiology of addiction comes from studies that require animals to perform a repeated behavior, such as a lever-press or nose-poke, to gain access to a drug. These behaviors typically become habits controlled by the dorsal striatum, leaving open the question of whether more complex behaviors, like the flexible problem-solving that humans use to navigate drug dealing, can also lead to addiction.

    Diverging from conventional animal models of addiction, Bryan Singer and colleagues instead required male rats to solve a new, increasingly difficult puzzle each day in order to receive a cocaine reward. This model still produced symptoms of substance use disorders in the rats. Drug-seeking behavior engaged the nucleus accumbens, a brain region involved in goal-directed behavior, throughout the experiment. The authors did not observe a shift in dopamine signaling to the dorsal striatum, which is thought to underlie the transition from learned behavior to habit, suggesting that the rats continued to rely on ingenuity to sustain their addiction.


  5. Study examines relationship between traumatic brain injury and alcohol use

    November 27, 2017 by Ashley

    From the Elsevier press release:

    Head injury, which often damages brain regions overlapping with those involved in addictive behaviors, does not worsen drinking behavior in people with heavy alcohol use, according to a new study published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging. The study, led by Dr. Andrew Mayer of the Mind Research Network and University of New Mexico in Albuquerque, New Mexico, also found that combining head injury with heavy alcohol use did not further alter the structure or function of the brain.

    “Individuals who consume too much alcohol are prone to experience more accidents as a result of their intoxication,” said Dr. Mayer. Importantly, he added, heavy alcohol use and traumatic brain injury (TBI) affect similar regions of the brain. This has led researchers to think that the common combination of head injury and heavy drinking may interact to worsen the brain damage already caused by chronic alcohol exposure.

    The study compared people with a recent history of heavy alcohol use and TBI with a control group carefully matched on lifetime history of alcohol exposure. Mayer and colleagues found the opposite of what they expected — heavy drinkers with a history of a TBI did not have worse drinking behavior, such as how often and how much they drank, compared with drinkers without a history of TBI.

    The researchers also used imaging techniques to measure the structure of the brain and its activity when the participants were given a taste of their favorite drink. “On average, the brains of the two groups were similar both in terms of the amount of lost tissue, as well as how each person’s brain responded to their favorite drink,” said Dr. Mayer, suggesting that TBI does not further damage brain circuitry in heavy drinkers.

    “The observation that the participants with TBI did not have greater neurocircuitry dysfunction than those without TBI might translate into greater therapeutic optimism for the treatment of individuals with a combination of TBI plus heavy drinking histories,” said Dr. Cameron Carter, Editor of Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.


  6. Higher estrogen levels linked to increased alcohol sensitivity in brain’s ‘reward center’

    November 14, 2017 by Ashley

    From the University of Illinois at Chicago press release:

    The reward center of the brain is much more attuned to the pleasurable effects of alcohol when estrogen levels are elevated, an effect that may underlie the development of addiction in women, according to a study on mice at the University of Illinois at Chicago.

    Led by Amy Lasek, assistant professor of psychiatry in the UIC College of Medicine, researchers found that neurons in a region of the brain called the ventral tegmental area, or VTA (also known as the “reward center”), fired most rapidly in response to alcohol when their estrogen levels were high. This response, according to their findings published online in the journal PLOS ONE, is mediated through receptors on dopamine-emitting neurons in the VTA.

    “When estrogen levels are higher, alcohol is much more rewarding,” said Lasek, who is the corresponding author on the paper and a researcher in the UIC Center for Alcohol Research in Epigenetics. “Women may be more vulnerable to the effects of alcohol or more likely to overindulge during certain stages of their cycle when estrogen levels are higher, or may be more likely to seek out alcohol during those stages.”

    Studies indicate that gender differences in psychiatric disorders, including addiction, are influenced by estrogen, one of the primary female sex hormones. Women are more likely to exhibit greater escalation of abuse of alcohol and other drugs, and are more prone to relapse in response to stress and anxiety.

    The VTA helps evaluate whether something is valuable or good. When neurons in this area of the brain are stimulated, they release dopamine — a powerful neurotransmitter responsible for feelings of wellness — and, in large doses, euphoria. When something good is encountered — for example, chocolate — the neurons in the VTA fire more rapidly, enforcing reward circuitry that encodes the idea that chocolate is enjoyable and something to be sought out. Over time, the VTA neurons fire more quickly at the sight, or even thought of, chocolate, explained Lasek. In addiction, VTA neurons are tuned into drugs of abuse, and fire more quickly in relation to consuming or even thinking about drugs, driving the person to seek them out — often at the expense of their own health, family, friends and jobs.

    Many animal studies have shown that alcohol increases the firing of dopamine-sensitive neurons in the VTA, but little is known about exactly why this occurs.

    Lasek and her colleagues examined the relationship between estrogen, alcohol and the VTA in female mice. They used naturally cycling mice that were allowed to go through their normal estrous cycles, akin to the menstrual cycle in women.

    Mice were evaluated to determine when they entered diestrus — the phase in the estrous cycle when estrogen levels are close to their peak.

    “In mice in diestrus, estrogen levels increase to about 10 times higher than they are in estrus, the phase in which ovulation occurs and estrogen levels drop,” Lasek said.

    VTAs were taken from mice in both estrus and diestrus and kept alive in special chambers. Electrodes recorded the activity of individual dopamine-sensitive neurons in the VTA. Next, the researchers added alcohol to the chamber. Activity increased twice as much in neurons from mice in diestrus compared to the response of neurons from mice in estrus.

    Lasek and her colleagues then blocked estrogen receptors on dopamine-sensitive neurons in VTA in mice in estrus and diestrus. With the blocker present, the response to alcohol in neurons from mice in diestrus was significantly lower compared with neurons where estrogen receptors remained functional. The estrogen receptor blocker reduced the alcohol response to levels seen in mice in estrus. The responses to alcohol in neurons from mice in estrus were unaffected by the estrogen receptor blocker.

    “The increased reward response to alcohol we see when estrogen levels are high is mediated through receptors for estrogen in the VTA,” said Mark Brodie, professor of physiology and biophysics in the UIC College of Medicine and a co-author on the paper.

    Lasek believes that the increased sensitivity to alcohol in the VTA when estrogen levels peak may play a significant role in the development of addiction in women.

    “We already know that binge drinking can lead to lasting changes in the brain, and in women, those changes may be faster and more significant due to the interaction we see between alcohol, the VTA and estrogen,” Lasek said. “Binge drinking can increase the risk of developing alcoholism, so women need to be careful about how much alcohol they drink. They should be aware that they may sometimes inadvertently over-consume alcohol because the area of the brain involved in alcohol reward is responding very strongly.”


  7. Study suggests frequent alcohol drinking kills new brain cells in adults, females are more vulnerable

    November 13, 2017 by Ashley

    From the University of Texas Medical Branch at Galveston  press release:

    Researchers from The University of Texas Medical Branch at Galveston recently discovered that alcohol killed the stem cells residing in adult mouse brains. Because the brain stems cells create new nerve cells and are important to maintaining normal cognitive function, this study possibly opens a door to combating chronic alcoholism.

    The researchers also found that brain stem cells in key brain regions of adult mice respond differently to alcohol exposure, and they show for the first time that these changes are different for females and males. The findings are available in Stem Cell Reports.

    Chronic alcohol abuse can cause severe brain damage and neurodegeneration. Scientists once believed that the number of nerve cells in the adult brain was fixed early in life and the best way to treat alcohol-induced brain damage was to protect the remaining nerve cells.

    “The discovery that the adult brain produces stem cells that create new nerve cells provides a new way of approaching the problem of alcohol-related changes in the brain,” said Dr. Ping Wu, UTMB professor in the department of neuroscience and cell biology. “However, before the new approaches can be developed, we need to understand how alcohol impacts the brain stem cells at different stages in their growth, in different brain regions and in the brains of both males and females.”

    In the study, Wu and her colleagues used a cutting-edge technique that allows them to tag brain stem cells and observe how they migrate and develop into specialized nerve cells over time to study the impact of long-term alcohol consumption on them.

    Wu said that chronic alcohol drinking killed most brain stem cells and reduced the production and development of new nerve cells.

    The researchers found that the effects of repeated alcohol consumption differed across brain regions. The brain region most susceptible to the effects of alcohol was one of two brain regions where new brain cells are created in adults.

    They also noted that female mice showed more severe deficits than males. The females displayed more severe intoxication behaviors and more greatly reduced the pool of stem cells in the subventricular zone.

    Using this model, scientists expect to learn more about how alcohol interacts with brain stem cells, which will ultimately lead to a clearer understanding of how best to treat and cure alcoholism.

    Other authors include UTMB’s Erica McGrath, Junling Gao, Yong Fang Kuo, Tiffany Dunn, Moniqua Ray, Kelly Dineley, Kathryn Cunningham and Bhupendra Kaphalia.


  8. Study suggests smoking, binge drinking and unsafe tanning may be linked in men

    November 11, 2017 by Ashley

    From the University of Connecticut press release:

    Even though men use tanning beds at lower rates than women, men who tan tend to do it in riskier ways, according to a study by researchers at the University of Connecticut. The findings should help public health officials rethink how, and to whom, they’re targeting anti-tanning messages.

    Because the stereotypical tanning salon client is a young woman, almost all the research and health messaging on tanning has focused on that demographic. But the new research in press in the Journal of the American Academy of Dermatology found that one in three people who use tanning beds in the U.S. are male.

    Men who tan report using tanning beds with about the same frequency as women, but smoke and binge drink at higher rates than their female counterparts, and they also tend to treat tanning more like an addiction than women do, say the authors. A full 49 percent of men who used tanning beds fit a pattern of addictive behavior around tanning.

    “That was really surprising,” says lead author Sherry Pagoto, a clinical psychologist and director of the UConn Center for mHealth and Social Media. “If they tan with the same frequency as women, why would tanning in men be more addictive?”

    Pagoto and her colleagues conducted a national survey of 636 people who answered “yes” when asked whether they had ever used a tanning bed. They queried the participants about frequency of use, preferred locations to tan, how they felt about tanning, and why they did it.

    The differences between men and women were marked. Women preferred to tan in salons, and said they valued low cost, cleanliness, and convenience. Men who tanned preferred less regulated settings, such as gyms or private homes. They said they liked to tan to accentuate the appearance of their muscles, or as a reward after working out. They also reported smoking tobacco, binge drinking alcohol, and drinking soda significantly more often than women who tan.

    Men also answered “yes” when asked if they ever felt anxious if they weren’t able to tan, tanned to relieve stress, or spent money on tanning even when they couldn’t afford it. They agreed with statements such as “I’d like to quit but I keep going back to it.”

    There’s a population of men who tan and engage in other risky behaviors and are very unlike the young women that health educators assume are at risk of tanning bed health impacts, says Pagoto.

    Pagoto and her team are pursuing another study to delve more deeply into who tans, asking questions about sexual orientation, given that recent research has revealed that homosexual men are just as likely to use tanning beds as young women. The research should help health officials trying to warn the public of the very real connection between tanning beds and skin cancer, she says.

    Sun lamps and tanning beds are legal for adult use in all 50 states, even though the Food and Drug Administration (FDA) classifies them as a Class 1 carcinogen like tobacco, radon, and arsenic, and the use of tanning beds has been linked to melanoma, the deadliest form of skin cancer.

    Most current marketing messaging is targeted to teen- and college-aged women, according to Pagoto. Men who tan are unlikely to relate to that type of message. Pagoto is now applying social media marketing principles to develop prevention messages that resonate with specific audience segments.

    “We’re also hoping to spread the message on college campuses, since the tanning industry heavily markets to college students,” she says.


  9. Study looks at how gut and gender may affect ease of quitting smoking

    November 6, 2017 by Ashley

    From the American Chemical Society:

    Many people who smoke or chew tobacco can’t seem to escape nicotine’s addictive properties. Studies show that women in particular seem to have a harder time quitting, even with assistance, when compared to men. Now, scientists report in a mouse study published in ACS’ journal Chemical Research in Toxicology that the difference in gender smoking patterns and smoking’s effects could be due to how nicotine impacts the brain-gut relationship.

    Cigarette smoking has long been a major public health issue. It’s related to one out of every five deaths in the U.S., according to the U.S. Centers for Disease Control and Prevention. When a person smokes tobacco, nicotine is delivered mainly to the lungs. But with skin patches and chewing tobacco, nicotine crosses the skin and into the gastrointestinal tract, respectively. Previous research has shown that nicotine and the nervous system interact, producing a number of effects including the release of the “feel-good” chemical dopamine. Studies have also shown that the effects of nicotine are gender-dependent. To more fully understand why this is, Kun Lu and colleagues wanted to explore how nicotine affects male and female gut microbiomes.

    The researchers set up a 13-week experiment during which they administered nicotine-infused water to mice. An analysis of the animals’ fecal samples showed major differences in the composition of the microbiomes in male and female mice. Levels of compounds and bacterial genes associated with the nervous system and body weight were altered in different ways in male and female mice. For example, the mice exposed to nicotine, especially the males, had lower concentrations of glycine, serine, and aspartic acid, which could weaken the addictive effect of nicotine. In addition, nicotine-treated female mice had reduced amounts of Christensenellaceae bacteria, while the treated male mice had increased levels, which are associated with a lower body mass index. The team says future efforts will focus on exploring the relationship of the nicotine-gut-brain interactions on a molecular level to further understand the communication paths involved.


  10. Early age of drinking leads to neurocognitive and neuropsychological damage

    November 4, 2017 by Ashley

    From the Research Society on Alcoholism press release:

    Although drinking by U.S. adolescents has decreased during the last decade, more than 20 percent of U.S. high-school students continue to drink alcohol before the age of 14 years. This can have adverse effects on their neurodevelopment. For example, youth who initiate drinking before 14 years of age are four times more likely to develop psychosocial, psychiatric, and substance-use difficulties than those who begin drinking after turning 20 years of age. Little is known about howthe age of alcohol-use onset influences brain development. This is the first study to assess the association between age of adolescent drinking onset and neurocognitive performance, taking into account pre-existing cognitive function.

    The researchers examined data from a longitudinal study on the neurocognitive effects of substance use in adolescents: 215 adolescents (127 boys, 88 girls) with minimal alcohol use experience were administered a neuropsychological test battery, which was repeated an average of 6.8 years later. Analyses examined whether earlier ages of onset for first and weekly alcohol use adversely affected neurocognition, controlling for substance-use severity, and familial and social environment factors.

    Results showed that an earlier onset of drinking increases the risk for alcohol-related neurocognitive vulnerabilities, and that the initiation of any or weekly alcohol use at younger ages is a risk factor for poorer, subsequent neuropsychological functioning. More specifically, an earlier age of onset of first drinking predicted poorer performance in the domains of psychomotor speed and visual attention, and an earlier age of onset of weekly drinking predicted poorer performances on tests of cognitive inhibition and working memory. The authors suggested that these findings have important implications for public policies related to the legal drinking age and prevention strategies and further research on these effects is warranted.