Why do some not become deathly ill from Ebola?

Genetic factors behind surviving or dying from Ebola shown in mouse study

Date:

October 30, 2014

Source:

University of Washington Health Sciences/UW Medicine

Summary:

A newly developed mouse model suggests that genetic factors are behind the mild-to-deadly range of responses to the Ebola virus. The frequency of different manifestations of the disease across the lines of these mice are similar in variety and proportion to the spectrum of clinical disease observed in the 2014 West African outbreak. The new mouse model might be useful in testing candidate therapeutics and vaccines for Ebola, and in finding genetic markers for susceptibility and resistance to the disease.

How is your sleep?

Severity of sleep apnea impacts risk of resistant high blood pressure

Date:

August 14, 2014

Source:

American Academy of Sleep Medicine

Summary:

A strong association between severe, untreated obstructive sleep apnea and the risk of elevated blood pressure despite the use of high blood pressure medications has been made by researchers. "High blood pressure that is resistant to treatment with medications is a strong warning sign for the presence of obstructive sleep apnea, a chronic disease that increases the risk for heart disease and stroke," said one expert.

Save the children

Student homelessness hits another record high

September 22 

CNN

 

NEW YORK

A growing number of students don't have homes to return to once classes are out.

Approximately 1.3 million students enrolled in U.S. public preschools, elementary schools, middle schools and high schools schools were homeless during the 2012-13 school year.

That's up 8% from the prior year, and the highest number on record, according to the National Center for Homeless Education, funded by the Department of Education.

Endangered assets. Protect teens from marijuana!

 

 

Regular marijuana use bad for teens' brains, study finds

Date:

August 9, 2014

Source:

American Psychological Association (APA)

Summary:

Frequent marijuana use can have a significant negative effect on the brains of teenagers and young adults, including cognitive decline, poor attention and memory, and decreased IQ, according to psychologists. "It needs to be emphasized that regular cannabis use, which we consider once a week, is not safe and may result in addiction and neurocognitive damage, especially in youth," said one expert.

"It needs to be emphasized that regular cannabis use, which we consider once a week, is not safe and may result in addiction and neurocognitive damage, especially in youth," said Krista Lisdahl, PhD, director of the brain imaging and neuropsychology lab at University of Wisconsin-Milwaukee.
Marijuana use is increasing, according to Lisdahl, who pointed to a 2012 study showing that 6.5 percent of high school seniors reported smoking marijuana daily, up from 2.4 percent in 1993. Additionally, 31 percent of young adults (ages 18 to 25) reported using marijuana in the last month. People who have become addicted to marijuana can lose an average of six IQ points by adulthood, according to Lisdahl, referring to a 2012  

longitudinal study of 1,037 participants who were followed from birth to age 38.
Brain imaging studies of regular marijuana users have shown significant changes in their brain structure, particularly among adolescents, Lisdahl said. Abnormalities in the brain's gray matter, which is associated with intelligence, have been found in 16- to 19-year-olds who increased their marijuana use in the past year, she said. These findings remained even after researchers controlled for major medical conditions, prenatal drug exposure, developmental delays and learning disabilities, she added.

"When considering legalization, policymakers need to address ways to prevent easy access to marijuana and provide additional treatment funding for adolescent and young adult users," she said. She also recommended that legislators consider regulating levels of tetrahydrocannabinol, or THC, the major psychoactive chemical in marijuana, in order to reduce potential neurocognitive effects.
Some legalized forms of marijuana have higher levels of THC than other strains, said Alan Budney, PhD, of Dartmouth College. THC is responsible for most of marijuana's psychological effects. Some research has shown that frequent use of high potency THC can increase risk of acute and future problems with depression, anxiety and psychosis. "Recent studies suggest that this relationship between marijuana and mental illness may be moderated by how often marijuana is used and potency of the substance," Budney said. "Unfortunately, much of what we know from earlier research is based on smoking marijuana with much lower doses of THC than are commonly used today." Current treatments for marijuana addiction among adolescents, such as brief school interventions and outpatient counseling, can be helpful but more research is needed to develop more effective strategies and interventions, he added.
Additionally, people's acceptance of legalized medical marijuana use appears to have an effect on adolescents' perception of the drug's risks, according to Bettina Friese, PhD, of the http://www.pire.org/index.aspPacific Institute for Research and Evaluation in California. She presented results from a 2013 study of 17,482 teenagers in Montana, which found marijuana use among teenagers was higher in counties where larger numbers of people voted to legalize medical marijuana in 2004. In addition, teens in counties with more votes for the legalization of medical marijuana perceived marijuana use to be less risky. The research findings suggest that a more accepting attitude toward medical marijuana may have a greater effect on marijuana use among teens than the actual number of medical marijuana licenses available, Friese said.

---

Story Source:
The above story is based on materials provided by American Psychological Association (APA). Note: Materials may be edited for content and length.

For the First Time: Dyslexia Brain Connectivity Mapped.

Dyslexia, the most commonly diagnosed learning disability in the United States, 

is a neurological reading disability that occurs when the regions of the brain 

that process written language don't function normally.

The use of non-invasive functional neuroimaging tools has helped characterize how brain activity is disrupted in dyslexia. However, most prior work has focused on only a small number of brain regions, leaving a gap in our understanding of how multiple brain regions communicate with one another through networks, called functional connectivity, in persons with dyslexia.
This led neuroscience PhD student Emily Finn and her colleagues at the Yale University School of Medicine to conduct a whole-brain functional connectivity analysis of dyslexia using functional magnetic resonance imaging (fMRI). They report their findings in the current issue of Biological Psychiatry.
"In this study, we compared fMRI scans from a large number of both children and young adults with dyslexia to scans of typical readers in the same age groups. Rather than activity in isolated brain regions, we looked at functional connectivity, or coordinated fluctuations between pairs of brain regions over time," explained Finn.
In total, they recruited and scanned 75 children and 104 adults. Finn and her colleagues then compared the whole-brain connectivity profiles of the dyslexic readers to the non-impaired readers, which revealed widespread differences.
Dyslexic readers showed decreased connectivity within the visual pathway as well as between visual and prefrontal regions, increased right-hemisphere connectivity, reduced connectivity in the visual word-form area, and persistent connectivity to anterior language regions around the inferior frontal gyrus. This altered connectivity profile is consistent with dyslexia-related reading difficulties.
Dr. John Krystal, Editor of Biological Psychiatry, said, "This study elegantly illustrates the value of functional imaging to map circuits underlying problems with cognition and perception, in this case, dyslexia."
"As far as we know, this is one of the first studies of dyslexia to examine differences in functional connectivity across the whole brain, shedding light on the brain networks that crucially support the complex task of reading," added Finn. "Compared to typical readers, dyslexic readers had weaker connections between areas that process visual information and areas that control attention, suggesting that individuals with dyslexia are less able to focus on printed words."
Additionally, young-adult dyslexic readers maintained high connectivity to brain regions involved in phonology, suggesting that they continue to rely on effortful "sounding out" strategies into adulthood rather than transitioning to more automatic, visual-based strategies for word recognition.
A better understanding of brain organization in dyslexia could potentially lead to better interventions to help struggling readers.

---

Story Source:
The above story is based on materials provided by Elsevier. Note: Materials may be edited for content and length.

Journal Reference:

1. Emily S. Finn, Xilin Shen, John M. Holahan, Dustin Scheinost, Cheryl Lacadie, Xenophon Papademetris, Sally E. Shaywitz, Bennett A. Shaywitz, R. Todd Constable. Disruption of Functional Networks in Dyslexia: A Whole-Brain, Data-Driven Analysis of Connectivity. Biological Psychiatry, 2014; 76 (5): 397 DOI: 10.1016/j.biopsych.2013.08.031

---

Cite This Page:

• APA
• Chicago

Elsevier. "Readers with dyslexia have disrupted network connections in the brain, map the circuitry of dyslexia shows." ScienceDaily. ScienceDaily, 28 August 2014. <www.sciencedaily.com/releases/2014/08/140828091245.htm>.

Habenula! Powerful findings.

 

Brain region for resisting alcohol's allure found

Date:

April 2, 2014

Source:

University of Utah Health Sciences

Summary:

When a region of the brain called the lateral habenula is chronically inactivated in rats, they repeatedly drink to excess and are less able to learn from the experience, neuroscientists report. The study has implications for understanding behaviors that drive alcohol addiction. "If we can understand the brain circuits that control sensitivity to alcohol's aversive effects, then we can start to get a handle on who may become a problem drinker," said the lead researcher.

1/2 of a pea size evolutionary ancient part of our brain tracks painful experiences!

A Look at How We Process Painful Experiences

By DOUGLAS QUENQUAAUG. 4, 2014

A tiny part of the brain keeps track of painful experiences and helps determine how we will react to them in the future, scientists say. The findings could be a boon to depression treatments.

The habenula (pronounced ha-BEN-you-la), a part of the brain less than half the size of a pea, has been shown in animal studies to activate during painful or unpleasant episodes.

Using M.R.I.s to produce powerful brain scans, researchers at University College London tracked the habenulas in subjects who were hooked up to electric shock machines. The subjects were presented with a series of photographs, some of which were followed by increasingly strong shocks. Soon, when the subjects were shown pictures associated with shocks, their habenulas would light up.

“The habenula seems to track the associations with electric shocks becoming stronger and stronger,” said Jonathan Roiser, a neuroscientist at the college and an author of the study, published in The Proceedings of the National Academy of Sciences.

The habenula appeared to have an effect on motivation, too. The subjects had been asked to occasionally press a button, just to show they were awake. They were much slower to do so when their habenula was active. In fact, the more slowly they responded, the more reliably their habenulas tracked associations with shocks.

In animals, the habenula has been shown to suppress production of dopamine, a chemical that drives motivation. Perhaps, the researchers say, an overactive habenula can cause the feelings of impending doom and low motivation common in people with depression. DOUGLAS QUENQUA

A version of this article appears in print on August 5, 2014, on page D2 of the New York edition with the headline: Neuroscience: A Look at How We Process Painful Experiences. 

New findings about treatment resistant depression

Intranasal Ketamine Delivers Rapid Antidepressant Effect

Caroline Cassels

April 09, 2014

Intranasal ketamine delivers a rapid antidepressant effect in patients with treatment-resistant major depressive disorder (MDD), new research shows.

Investigators report that the N-methyl-D-asparate (NMDA) glutamate receptor, administered via intranasal spray, had a significant antidepressant effect within 24 hours of administration. If confirmed in larger studies, the researchers say these findings may herald a new antidepressant drug class.

"What we have here is a proof-of-concept study, and we consider the results very promising. We hope to see this line of research further developed so that we have more treatments to offer patients with severe, difficult-to-treat major depressive disorder," study investigator Dennis S. Charney, MD, Icahn School of Medicine at Mount Sinai in New York City, said in a release.

The study was published online April 2 in Biological Psychiatry.

Common Anesthetic

A US Food and Drug Administration (FDA)–approved anesthetic that has been in common use for years, ketamine has also been subverted as a drug of abuse and can lead to serious psychiatric or cognitive problems when misused.

Previous research conducted by the same group of investigators and reported by Medscape Medical News has shown that low-dose intravenous ketamine has a rapid effect on patients with resistant depression.

To determine the safety and efficacy of an intranasal formulation of the drug, the investigators conducted a small, double-blind, crossover study. A total of 20 patients with MDD who had failed to respond to at least 1 trial of antidepressants were randomly assigned to receive a single 50-mg dose of ketamine or saline 7 days apart.

In each treatment period, study participants were assessed at 40 minutes, 120 minutes, 240 minutes, 24 hours, 48 hours, 72 hours, and 7 days following treatment intervention.

The study's primary outcome was change in depression severity, as measured by the Montgomery-Åsberg Depression Rating Scale (MADRS). Secondary outcomes included durability of response, changes in self-reports of depression, anxiety, and the proportion of responders.

The investigators also measured potential psychotomimetic, dissociative, hemodynamic, and general adverse effects.

Novel Mechanism

Study results based on 18 participants revealed greater improvement in depressive symptoms at 24 hours following ketamine administration compared with placebo [t = 4.39, P < .001; estimated mean MADRS score difference of 7.6 ± 3.7 (95% confidence interval, 3.9 - 11.3).

The researchers also found that 8 of 18 patients (44%) met response criteria 24 hours following ketamine administration vs 1 of 18 (6%) following placebo (P = .033).

The investigators also found that intranasal ketamine was "well tolerated with minimal psycotomimetic or dissociative effects and was not associated with clinically significant hemodynamic parameters."

Dr. James Murrough

"One of the primary effects of ketamine in the brain is to block the NMDA. There is an urgent clinical need for new treatments for depression with novel mechanisms of action. With further research and development, this could lay the groundwork for using NMDA-targeted treatments for major depressive disorder," principal investigator James Murrough, MD, said in a release.

"To our knowledge, this study represents the first controlled investigation of intranasal administration for an NMDA antagonist in depression. While these findings are suggestive of efficacy and of a favorable tolerability profile, much more research is required before the true efficacy and safety of this intervention can be assessed.

"Future studies designed to optimize dosing while identifying relapse prevention strategies and biomarkers of treatment response will provide additional needed data to maximize benefit for patients and minimize side effects," the investigators conclude.

Hello??? anyone listening? kids need help!

Three hours is enough to help prevent mental health issues in teens


Date: October 3, 2013 Source: Université de Montréal Summary: The incidence of mental health issues amongst 509 British youth was reduced by 25 to 33% over the 24 months following two 90-minute group therapy sessions. Almost one-in-four American 8 to 15 year olds has experienced a mental health disorder over the past year. We know that these disorders are associated with a plethora of negative consequences. This study shows that teacher delivered interventions that target specific risk factors for mental health problems can be immensely effective at reducing the incidence of depression, anxiety and conduct disorders in the long term.

Life is about Perception!

Uncovering a new angle on mental distance: Feeling closer leads to poor judgement of space

Date:

April 10, 2014

Source:

Association for Psychological Science

Summary:

Why does the second hour of a journey seem shorter than the first? Research suggests that the answer lies in how we're physically oriented in space. Research has demonstrated that a person's orientation -- the direction they are headed -- changed how they thought of an object or event. "Feeling close to or distant from something impacts our behavior and judgment," says the lead author. "We feel more socially connected, more emotionally engaged, and more attuned to the present when something is perceived as close."

WOW! Science Rocks.... A new world.

Researchers search for earliest roots of psychiatric disorders

Date:

April 10, 2014

Source:

Yale University

Summary:

A single molecular mechanism in the developing brain has been identified that sheds light on how cells may go awry when exposed to a variety of different environmental insults. The findings suggest that different types of stressors prenatally activate a single molecular trigger in brain cells that may make exposed individuals susceptible to late-onset neuropsychiatric disorders.

"Sexuality is NOT a choice" Science vs. Opinion

• Ian Sample, science correspondent
• The Guardian, Thursday 13 February 2014

A study of gay men in the US has found fresh evidence that male sexual orientation is influenced by genes. Scientists tested the DNA of 400 gay men and found that genes on at least two chromosomes affected whether a man was gay or straight.

A region of the X chromosome called Xq28 had some impact on men's sexual behaviour – though scientists have no idea which of the many genes in the region are involved, nor how many lie elsewhere in the genome.

Another stretch of DNA on chromosome 8 also played a role in male sexual orientation – though again the precise mechanism is unclear.

Researchers have speculated in the past that genes linked to homosexuality in men may have survived evolution because they happened to make women who carried them more fertile. This may be the case for genes in the Xq28 region, as the X chromosome is passed down to men exclusively from their mothers.

Michael Bailey, a psychologist at Northwestern University in Illinois, set out the findings at a discussion event held in conjunction with the annual meeting of the American Association for the Advancement of Science in Chicago on Thursday. "The study shows that there are genes involved in male sexual orientation," he said. The work has yet to be published, but confirms the findings of a smaller study that sparked widespread controversy in 1993, when Dean Hamer, a scientist at the US National Cancer Institute, investigated the family histories of more than 100 gay men and found homosexuality tended to be inherited. More than 10% of brothers of gay men were gay themselves, compared to around 3% of the general population. Uncles and male cousins on the mother's side had a greater than average chance of being gay, too.

The link with the mother's side of the family led Hamer to look more closely at the X chromosome. In follow-up work, he found that 33 out of 40 gay brothers inherited similar genetic markers on the Xq28 region of the X chromosome, suggesting key genes resided there.

Hamer faced a firestorm when his study was published. The fuss centred on the influences of nature and nurture on sexual orientation. But the work also raised the more dubious prospect of a prenatal test for sexual orientation. The Daily Mail headlined the story "Abortion hope after 'gay genes findings' ". Hamer warned that any attempt to develop a test for homosexuality would be "wrong, unethical and a terrible abuse of research".

The gene or genes in the Xq28 region that influence sexual orientation have a limited and variable impact. Not all of the gay men in Bailey's study inherited the same Xq28 region. The genes were neither sufficient, nor necessary, to make any of the men gay.

The flawed thinking behind a genetic test for sexual orientation is clear from studies of twins, which show that the identical twin of a gay man, who carries an exact replica of his brother's DNA, is more likely to be straight than gay. That means even a perfect genetic test that picked up every gene linked to sexual orientation would still be less effective than flipping a coin.

While genes do contribute to sexual orientation, other multiple factors play a greater role, perhaps including the levels of hormones a baby is exposed to in the womb. "Sexual orientation has nothing to do with choice," said Bailey. "We found evidence for two sets [of genes] that affect whether a man is gay or straight. But it is not completely determinative; there are certainly other environmental factors involved."

Last year, before the latest results were made public, one of Bailey's colleagues, Alan Sanders, said the findings could not and should not be used to develop a test for sexual orientation.

"When people say there's a gay gene, it's an oversimplification," Sanders said. "There's more than one gene, and genetics is not the whole story. Whatever gene contributes to sexual orientation, you can think of it as much as contributing to heterosexuality as much as you can think of it contributing to homosexuality. It contributes to a variation in the trait."

Qazi Rahman, a psychologist at King's College London, said the results were valuable for further understanding the biology of sexual orientation. "This is not controversial or surprising and is nothing people should worry about. All human psychological traits are heritable, that is, they have a genetic component," he said. "Genetic factors explain 30 to 40% of the variation between people's sexual orientation. However, we don't know where these genetic factors are located in the genome. So we need to do 'gene finding' studies, like this one by Sanders, Bailey and others, to have a better idea where potential genes for sexual orientation may lie."

Rahman rejected the idea that genetics research could be used to discriminate against people on the basis of their sexual orientation. "I don't see how genetics would contribute more to the persecution, discrimination and stigmatisation of lesbian, gay, bisexual and transgender people any more than social, cultural or learning explanations. Historically, the persecution and awful treatment of LGBT groups has been because politicians, religious leaders and societies have viewed sexual orientation as 'choice' or due to poor upbringing."