Rat study suggests way to trick pleasure centre in drug addicts' brains
Inducing a 'runners' high' in rats conditioned to be extremely active made them less active
Activating the pleasure and reward receptors in the brains of extremely energetic rats made the rats much less inclined to exercise, in lab tests by University of Missouri scientists. The researchers say this finding could lead to treatments for drug addicts. By activating the mu-opioid receptors in the brain to release the pleasure-inducing chemical dopamine, the "reward" of dangerous drugs could be provided without having to consume those drugs. The rats were selectively bred to be extremely active or lazy. Studying the rats' brains, the researchers found 400 per cent more of the reward receptors in the active than in the lazy rats. They believe this indicates that the active rats were active to receive "rewards" from their mu-opioid receptors, which may explain why they voluntarily run such extreme amounts. The study was published in the journal .
Teenagers who spend a lot of time on the internet may be at risk of suffering high blood pressure, say researchers at Henry Ford Hospital in Detroit. Their study, the results of which were published in the involved 335 teenagers aged 14 to 17 who spent at least 14 hours a week on the internet and had elevated blood pressure. The participants completed a physical exam as well as a survey of their internet use. Of 134 who were classified as heavy internet users (average of 25 hours a week), 26 had elevated blood pressure. Among heavy internet users, 43 per cent were overweight, compared to 26 per cent of light internet users. Andrea Cassidy-Bushrow, the study's lead author, says the message for teenagers and parents is moderation. "It's important that young people take regular breaks from their computer or smartphone, and engage in some form of physical activity," she says. "I recommend to parents they limit their children's' time at home on the internet. I think two hours a day, five days a week is good rule of thumb."
People with heart disease may benefit from maintaining positive emotions. Over the course of five years, researchers at Penn State University in the US tracked more than 1,000 patients with coronary heart disease. Patients who reported higher positive psychological states were more likely to be physically active, sleep better and take their heart medication and were also less likely to smoke, compared to patients with lower levels of positive states. These long-term health habits are important for reducing the risk of future heart problems and death, the researchers say in their report in . The researchers suggest several explanations for the findings. People with greater positive well-being may be more motivated and persistent in engaging in healthy behaviour. They might have more confidence in their ability to maintain routines such as physical activity and sleep hygiene. Positive emotions may also enable people to better adjust their health goals and to proactively cope with stress and setbacks.
