Tag Archives: chemical

Ultimate Killing Machine: The Guilt Free Soldier

Anti-fear drug ‘could help wipe painful memories’

By Steve Connor, Science Editor

Friday, 4 June 2010

Research suggests anti-fear medication could help soldiers deal with post-traumatic stress disorder

The prospect of being able to take a pill to combat fear and anxiety has come a step closer, with a study showing that it is possible to overcome bad memories of painful situations with the help of a chemical that works on the brain.

The discovery raises the possibility of a new class of drugs to alleviate post-traumatic stress disorder or the symptoms of extreme anxiety. It may even lead to suggestions that soldiers or other personnel in dangerous professions will be able to take anti-fear medications during stressful situations.

The study was carried out on laboratory rats and it will still take many years of clinical trials in humans before such drugs can be used by the wider population. Scientists are nevertheless confident that new treatments for fear-related illnesses and anxiety disorders will emerge from the research.

Rather than working in the same way as a conventional sedative or anti-depressant, the new chemical stimulates the area of the brain thought to be involved in remembering a painful situation from the past. The chemical, called brain-derived neurotrophic factor (BDNF), is naturally produced in the brain and is involved in learning and memory. When given to the rats, the drug caused them to re-learn a painful association so that the memory of it is extinguished – although not lost entirely.

An Anti-Anxiety Drug That Could Create Super-Soldiers


“Many lines of evidence implicate BDNF in mental disorders. This work supports the idea that medications could be developed to augment the effects of BDNF, providing opportunities for pharmaceutical treatment of post-traumatic stress disorder and other anxiety disorders,
” said Thomas Insel, director of the US National Institute of Mental Health.

The study, published in the journal Science, investigated how laboratory rats freeze when they hear a sound that they have associated with a small electric shock to their feet. It is possible to overcome this fear of the sound by training the animals with a series of similar sounds not associated with painful shocks.

But by injecting BDNF, a protein that stimulates the growth of nerve cells, into the brains of the rats, the scientists found they could mimic the effects of the retraining process. This chemical mimicry only worked if they put BDNF into a part of the brain called the infralimbic prefrontal cortex, a structure that appears to be critical for the extinction of memory.

The drug seems to induce a “memory of safety” in the rats that overrides the fearful memory. In effect, the BDNF drug mimics the effect of retraining the rats to extinguish the memory of the painful situation, said Gregory Quirk of the University of Puerto Rico School of Medicine, who led the investigation.

The surprising finding here is that the drug substituted for extinction training, suggesting that it induced such a memory [of safety],” Dr Quirk said.

This was seen to be important because a failure to extinguish the fear associated with painful memories is thought to contribute to anxiety disorders, such as post-traumatic stress disorder, the researchers said. Previous research, for instance, has found that patients with post-traumatic stress disorder have an infralimbic prefrontal cortex which is smaller than normal, they said.

“Our finding suggests that augmenting BDNF in these [brain] circuits may ameliorate post-traumatic stress disorder and perhaps other disorders such as addictions
,” said Jamie Peters, who collaborated on the research project.

BDNF is naturally produced in the brain and has been shown to play a critical role in stimulating the growth of the important nerve endings between brain cells that allow memories to be formed and learning experiences to be remembered.

Further experiments showed that administering BDNF did not erase the original bad memory in the rats, because it was just as easy to reinstate the fearful association between the sound tone and the electric shock. However, the scientists suggested there may be ways of stimulating the natural release of BDNF in the human brain, thereby alleviating the effects of post-traumatic stress disorder and extreme anxiety.

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CDC Warns Public to Prepare for ‘Zombie Apocalypse’

Education
CDC Warns Public to Prepare for ‘Zombie Apocalypse’

By Joshua Rhett Miller

Are you prepared for the impending zombie invasion?

Do you have the necessary Emergency Kits and Supplies?

That’s the question posed by the Centers for Diseases Control and Prevention in a Monday blog posting gruesomely titled, “Preparedness 101: Zombie Apocalypse.” And while it’s no joke, CDC officials say it’s all about emergency preparation.

“There are all kinds of emergencies out there that we can prepare for,” the posting reads. “Take a zombie apocalypse for example. That’s right, I said z-o-m-b-i-e a-p-o-c-a-l-y-p-s-e. You may laugh now, but when it happens you’ll be happy you read this, and hey, maybe you’ll even learn a thing or two about how to prepare for a real emergency.”

The post, written by Assistant Surgeon General Ali Khan, instructs readers how to prepare for “flesh-eating zombies” much like how they appeared in Hollywood hits like “Night of the Living Dead” and video games like Resident Evil. Perhaps surprisingly, the same steps you’d take in preparation for an onslaught of ravenous monsters are similar to those suggested in advance of a hurricane or pandemic.

“First of all, you should have an emergency kit in your house,”
the posting continues. “This includes things like water, food, and other supplies to get you through the first couple of days before you can locate a zombie-free refugee camp (or in the event of a natural disaster, it will buy you some time until you are able to make your way to an evacuation shelter or utility lines are restored).”

Other items to be stashed in such a kit include medications, duct tape, a battery-powered radio, clothes, copies of important documents and first aid supplies.

Once you’ve made your emergency kit, you should sit down with your family and come up with an emergency plan,” the posting continues. “This includes where you would go and who you would call if zombies started appearing outside your doorstep. You can also implement this plan if there is a flood, earthquake or other emergency.”

The idea behind the campaign stemmed from concerns of radiation fears following the earthquake and tsunami that rocked Japan in March. CDC spokesman Dave Daigle told FoxNews.com that someone had asked CDC officials if zombies would be a concern due to radiation fears in Japan and traffic spiked following that mention.

“It’s kind of a tongue-in-cheek campaign,
” Daigle said Wednesday. “We were talking about hurricane preparedness and someone bemoaned that we kept putting out the same messages.”

While metrics for the post are not yet available, Daigle said it has become the most popular CDC blog entry in just two days.

“People are so tuned into zombies,” he said. “People are really dialed in on zombies. The idea is we’re reaching an audience or a segment we’d never reach with typical messages.”

Read more: http://www.foxnews.com/health/2011/05/18/cdc-warns-public-prepare-zombie-apocalypse/#ixzz1MlPfBN1O

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The Tricky Chemistry of Attraction

The Tricky Chemistry of Attraction

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Taking Birth-Control Pills May Mask the Signals That Draw the Sexes Together, Research Shows

By SHIRLEY S. WANG

Much of the attraction between the sexes is chemistry. New studies suggest that when women use hormonal contraceptives, such as birth-control pills, it disrupts some of these chemical signals, affecting their attractiveness to men and women’s own preferences for romantic partners.

Researchers say birth control pills are upending the natural influence of hormones on attraction. WSJ’s Shirley Wang reports on a new study in lemurs that show how contraceptives may influence the way the primates pick and choose their mates.

The type of man a woman is drawn to is known to change during her monthly cycle—when a woman is fertile, for instance, she might look for a man with more masculine features. Taking the pill or another type of hormonal contraceptive upends this natural dynamic, making less-masculine men seem more attractive, according to a small but growing body of evidence. The findings have led researchers to wonder about the implications for partner choice, relationship quality and even the health of the children produced by these partnerships.

Evolutionary psychologists and biologists have long been interested in factors that lead to people’s choice of mates. One influential study in the 1990s, dubbed the T-shirt study, asked women about their attraction to members of the opposite sex by smelling the men’s T-shirts. The findings showed that humans, like many other animals, transmit and recognize information pertinent to sexual attraction through chemical odors known as pheromones.

The study also showed that women seemed to prefer the scents of men whose immune systems were most different from the women’s own immune-system genes known as MHC. The family of genes permit a person’s body to recognize which bacteria are foreign invaders and to provide protection from those bugs. Evolutionarily, scientists believe, children should be healthier if their parents’ MHC genes vary, because the offspring will be protected from more pathogens.

Couples dancing in a ballroom. When women are ovulating, they tend to be drawn to men with greater facial symmetry and more signals of masculinity, such as muscle tone, a more masculine voice and dominant behaviors.

Seductive Science

What happens to a woman during her most fertile days?

Her voice becomes higher pitched.
Men are more attentive to her, with behavior ranging from thoughtful to jealous.
Her scent becomes more attractive to men.
She seeks men with more masculine features.
Her social behavior changes, including increased flirting.
She tries to look more attractive and may choose more-revealing clothing.
If she is with a less masculine man, she may feel less attracted to him.

More than 92 million prescriptions for hormonal contraceptives, including pills, patches and injections, were filled last year in the U.S., according to data-tracker IMS Health.

Researchers say their aim isn’t to scare or stop women from taking hormonal contraceptives. “We just want to know what we’re doing” by taking the pill, says Alexandra Alvergne, a researcher in biological anthropology at University College London in the U.K. “If there is a risk it affects our romantic life and the health status of our children, we want to know.” Dr. Alvergne last year published a review detailing the existing literature on the topic in the journal Trends in Ecology and Evolution.

Both men’s and women’s preferences in mates shift when a woman is ovulating, the period when she is fertile, research has shown. Some studies have tracked women’s responses to photos of different men, while other studies have interviewed women about their feelings for men over several weeks. Among the conclusions: When women are ovulating, they tend to be drawn to men with greater facial symmetry and more signals of masculinity, such as muscle tone, a more masculine voice and dominant behaviors. The women also seemed to be particularly attuned to MHC-gene diversity. From an evolutionary perspective, these signals are supposed to indicate that men are more fertile and have better genes to confer to offspring.

Women tend to exhibit subtle cues when they are ovulating, and men tend to find them more attractive at this time. Women try to look more attractive, perhaps by wearing tighter or more revealing clothing, says Martie Haselton, a communications and psychology professor at the University of California, Los Angeles. Research on this includes studies in which photos that showed women’s clothing choices at different times of the month were shown to groups of judges. Women also emit chemical signals that they are fertile; researchers have measured various body odors, says Dr. Haselton, who has a paper on men’s ability to detect ovulation coming out in the journal Current Directions in Psychological Science.

Such natural preferences get wiped out when the woman is on hormonal birth control, research has shown. Women on the pill no longer experience a greater desire for traditionally masculine men during ovulation. Their preference for partners who carry different immunities than they do also disappears. And men no longer exhibit shifting interest for women based on their menstrual cycle, perhaps because those cues signaling ovulation are no longer present, scientists say.

Some women using birth-control pills have long reported changes to their libido and mood. Research is still in the early stages to explore the implications of taking hormonal contraceptives for women’s choice of mates and for fidelity in relationships. Researchers speculate that women with less-masculine partners may become less interested in their partner when they come off birth control, contributing to relationship dissatisfaction. And, if contraceptives are masking women’s natural ability to detect genetic diversity, then the children produced by parents who met when the woman was on the pill may be less genetically healthy, they suggest.

“We don’t have enough research to draw a firm conclusion yet,
” says Dr. Haselton. “It is certainly possible that if women don’t experience that little uptick in [desiring] masculinity that they end up choosing less masculine partners,” she says.

That could prompt some women to stray, research suggests. Psychologist Steven Gangestad and his team at the University of New Mexico showed in a 2010 study that women with less-masculine partners reported an increased attraction for other men during their fertile phase. Women partnered with traditionally masculine partners didn’t have such urges, according to the study of 60 couples.

In another study, the researchers analyzed MHC gene samples of 48 couples. Women partnered with men with whom they shared the least genetic diversity reported being less sexually responsive to their mates. The study was published in 2006 in the journal Psychological Science.

There is also accumulating evidence indicating men react differently to women when they are on birth control. A 2004 study in the journal in Behavioral Ecology used the T-shirt study methodology but instead put the shirts on 81 women. A panel of 31 men, smelling the T-shirts, experienced the greatest attraction for the non-pill-using women when they were ovulating. Twelve women on the panel didn’t detect any difference.

A study on primates appears to support the idea that hormonal contraceptives change mating preferences. Duke University researchers studied hormones secreted by female lemurs before and after the animals received a hormonal contraceptive. They also studied males’ preferences for these scents.

The findings, published in the journal Proceedings of the Royal Society, Biological Sciences this year, showed that the injection of Depo-Prevara, a long-lasting contraceptive that is approved for use in humans, dramatically altered the chemicals that female lemurs give off to indicate their identity and how genetically healthy they are.

The females given the contraceptive became overall less appealing to the males than before getting the injection, says Christine Drea, a professor in Duke’s evolutionary anthropology department and senior author on the study. The contraceptive erased all the normal information the odor signals conveyed, she says.

Though the study would need to be conducted in humans to draw direct conclusions, there are potential parallels to people, Dr. Drea says. Birth control “could be mixing up your own [signals] and others aren’t smelling the real you,” she says.

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