Posts tagged with ‘UCSD’
We couldn’t resist this pic…from our friends @ ucsdhealthsciences:
In Rats and Men, Nicotine Withdrawal Casts Similar Pall
Reduced reward response in brains helps explain why it’s so hard to quit smoking
Efforts to quit smoking tend to end in failure. Almost half of smokers attempt to quit each year, but only 4 to 7 percent succeed on any given attempt without medicines or assistance, according to the American Cancer Society, and less than 25 percent of smokers who use medicines remain smoke-free for more than six months. Relapse is especially common within 48 hours of quitting when nicotine withdrawal symptoms are most acute.
In a set of novel experiments involving both humans and rats, researchers at the University of California, San Diego School of Medicine, Florida Atlantic University (FAU), University of Pittsburgh, Washington University and Harvard Medical School report that the brain’s response to reward – its ability to recognize and derive pleasure from natural stimuli such as food, money or sex – is measurably reduced after nicotine withdrawal.
The findings, published this week online in JAMA Psychiatry, suggest that nicotine withdrawal significantly impacts the ability to modulate behavioral choices based on the expectancy of reward. This deficit is seen often in people who suffer from depression.
“What we saw in both humans and rats was decreased responsiveness to reward,” said Athina Markou, PhD, professor and vice-chair of research in the Department of Psychiatry at UC San Diego. “During acute nicotine withdrawal, both people and animals attended less to positive rewards. That’s a hallmark of depression. And there is evidence that people who already express depressive symptoms and quit smoking are more likely to become clinically depressed and stay that way. These findings have an obvious bearing on how we approach cessation treatment.”
The study authors say the breadth of the findings involving similar results in two different species offer a strong translational framework for future studies that will allow development of clinical treatments focusing on reward responsiveness during early nicotine withdrawal.
“The fact that the effect was similar across species using this translational task not only provides us with a ready framework to proceed with additional research to better understand the mechanisms underlying withdrawal of nicotine, and potentially new treatment development, but it also makes us feel more confident that we are actually studying the same behavior in humans and rats as the studies move forward,” said Michele Pergadia, PhD, associate professor of clinical biomedical science in the Charles E. Schmidt College of Medicine at FAU.
The experiments reported in JAMA Psychiatry assessed reward responsiveness based upon the propensity to modulate behavior according to prior experience. In human testing, conducted at Washington University, participants were asked to repeat a computer task, with “correct” responses earning a modest financial reward. In testing at UC San Diego, rats were trained to press a lever upon hearing a specific tone to earn a food reward.
Results were similar. Human participants who were smokers but who had abstained from smoking for 24 hours prior to testing and rats chronically exposed to nicotine but deprived for 24 hours also prior to testing both performed less effectively than non-smokers and rats with no nicotine experience. That is, both humans and rats withdrawing from nicotine failed to display a bias toward maximizing their rewards.
Markou’s team, which included co-authors Andre Der-Avakian, PhD, and Manoranjan D’Souza, MD, PhD, subsequently re-exposed rats to nicotine and re-tested them. This time, the animals showed a heightened reward response, stronger than before.
“This finding indicates that after the initial withdrawal, if a relapse occurs, it will produce a more pleasurable effect. That’s why smokers who have a single cigarette after quitting often find it triggers a full relapse and they’re soon back to smoking as much as before.”
Markou and Pergadia say the findings open up two avenues of future research: Studying the neurobiology of the reward response phenomenon to pinpoint where in the brain it occurs and which circuits or neurons are involved; and assessing potential medications on rats during reward response testing. Promising drugs, if approved by the FDA for human administration, could then be tested on humans in similar experiments – an approach that could provide both new insights and speed the drug development process.
Possessive puppies: Jealous behaviors in dogs
Emotion researchers have been arguing for years whether jealousy requires complex cognition. And some scientists have even said that jealousy is an entirely social construct — not seen in all human cultures and not fundamental or hard-wired in the same ways that fear and anger are.
A current study by UC San Diego professor Christine Harris is the first experimental test of jealous behaviors in dogs. The findings support the view that there may be a more basic form of jealousy, which evolved to protect social bonds from interlopers.
“Our study suggests not only that dogs do engage in what appear to be jealous behaviors but also that they were seeking to break up the connection between the owner and a seeming rival,” Harris said. “We can’t really speak to the dogs’ subjective experiences, of course, but it looks as though they were motivated to protect an important social relationship.”
Kittehs canz be jealoos, too …
¿Hablas otro idioma? Parlez-vous une autre langue? Сколько языков Вы знаете? Do you speak another language? If so, there are benefits that go beyond communication skills …
How small can a laser get? ucsandiego researchers are studying new ways to scale them to microscopic levels in order to use them on microchips. These nanolasers will allow computers to send much bigger amounts of data in a more energy efficient way.
After producing a story about UC San Diego materials scientists coming up with a novel method inspired by the narwhal’s long, spiral tooth, it was fun to see our local barista wearing a shirt emblazoned with the arctic whale.
Materials scientists at UC San Diego’s Jacobs School of Engineering have looked to the narwhal for bio-inspiration. This arctic whale’s spiraling tusk, which is a long tooth that juts out of its mouth, led researchers to invent a method called magnetic freeze casting. The result? Bio-inspired type bone. We’ll soon feature an interview with one of the researchers, Joanna McKittrick, about this new invention.
Bio-inspired materials essentially use Mother Nature as a guide. Materials scientist Joanna McKittrick of the University of California, San Diego’s Jacobs School of Engineering is interested in making new materials that have enhanced mechanical properties.
"And one way to do that is to look at how Mother Nature has created structures such as antlers or horns or porcupine quills, looking at feathers for example for lightweight structures. Same thing with the porcupine quills. Antlers and animal horns are impact resistant so they can absorb a lot of energy before they break. And that would be good for making bumpers or kneepads or helmets. "
Recently, McKittrick’s team has been inspired by the seahorse.
"The surprising thing about the seahorse is its tail. It can wrap and it can bend, it can curl up, but it can also curl to the sides. So it is very flexible and we thought wow that would make a good probe; that would make a good robot arm."
We really enjoyed our conversation with Drs. Albert Lin & Eliah Aronoff-Spencer at UC San Diego about their citizen sensor project that may revolutionize global health and environmental monitoring – especially in remote and undeveloped areas of the world. And yes, their device does bring to mind Spock and his trusty tricorder.