Well-rested flies

Therapeutic agent reduces age-related sleep problems in fruit flies

2014-04-02

(Press-News.org) This news release is available in German.

Elderly flies do not sleep well – they frequently wake up during the night and wander around restlessly. The same is true of humans. For researchers at the Max Planck Institute for Biology of Ageing in Cologne, the sleeplessness experienced by the fruit fly Drosophila is therefore a model case for human sleeping behaviour. The scientists have now discovered molecules in the flies' cells that affect how the animals sleep in old age: if insulin/IGF signalling is active, the quality of the animals' sleep is reduced and they wake up more often. Using a therapeutic agent, researchers managed to improve the flies' sleep again. The scientists suspect that the causes of sleep problems experienced by older flies and humans are similar. It is also possible that sleep problems encountered by humans may not necessarily be an inevitable side effect of ageing and may even be reversible.

Flies and humans sleep in much the same way. Just like us, flies sleep during the night and are active during the day. And the quality of sleep deteriorates as both species age: the individuals nap more frequently during the day and sleep for shorter periods at night.

Gerontologists are very familiar with the insulin/IGF (insulin-like growth factor) signalling pathway. It is actually a metabolic pathway that controls the cell's response to nutritional deficiency and also affects life expectancy. Fruit flies therefore live longer if the signalling pathway is less active. The signalling pathway also plays a role in ageing humans.

Researchers at the Cologne-based Max Planck Institute have now discovered that fruit flies sleep better at night and are more active during the day if insulin/IGF signalling is inhibited. "Daytime activity and night-time sleep are thereby controlled by two different components: during the day, the neurotransmitter octopamine and the adipokinetic hormone AKH increase activity in flies. At night, on the other hand, the neurotransmitter dopamine and the kinase TOR reduce the sleep periods," explains Luke Tain from the Max Planck Institute for Biology of Ageing.

Rapamycin is a substance that inhibits TOR activity, inhibiting the molecule. "We administered rapamycin to older flies and observed that they once again slept for longer periods. As a result, we were able to reverse the deterioration in sleep quality as a consequence of ageing," says Tain.

The cells of such different organisms as roundworms, flies and humans use the insulin/IGF signalling pathway. Its components and function are similar in various species of living organisms. The researchers now want to study whether the signal molecules in higher animals, such as mice, have the same effect. In this way, they hope to discover treatments that will improve sleep quality in old age.

INFORMATION: Original publication:

Athanasios Metaxakis, Luke S. Tain, Sebastian Grönke, Oliver Hendrich, Yvonne Hinze, Ulrike Birras & Linda Partridge
Lowered Insulin Signalling Ameliorates Age-Related Sleep Fragmentation in Drosophila
PLoS Biology, 2 April 2014

[Attachments] See images for this press release:

ELSE PRESS RELEASES FROM THIS DATE:

Penn Medicine points to new ways to prevent relapse in cocaine-addicted patients

2014-04-02

(PHILADELPHIA) – Relapse is the most painful and expensive feature of drug addiction—even after addicted individuals have been drug-free for months or years, the likelihood of sliding back into the habit remains high. The National Institute on Drug Abuse estimates that 40 to 60 percent of addicted individuals will relapse, and in some studies the rates are as high as 80 percent at six months after treatment. Though some relapse triggers can be consciously avoided, such as people, places and things related to drug use, other subconscious triggers related to the brain's reward ...

The mammography dilemma

2014-04-01

A comprehensive review of 50 year's worth of international studies assessing the benefits and harms of mammography screening suggests that the benefits of the screening are often overestimated, while harms are underestimated. And, since the relative benefits and harms of screening are related to a complex array of clinical factors and personal preferences, physicians and patients need more guidance on how best to individualize their approach to breast cancer screening. The results of the review by researchers at Harvard Medical School's Department of Health Care Policy ...

Overuse of blood transfusions increases infection risk

2014-04-01

ANN ARBOR, Mich. — Blood transfusions are one of the most common procedures patients receive in the hospital but the more red blood cells they receive, the greater their risk of infection, says a new study led by the University of Michigan Heath System and VA Ann Arbor Healthcare System. Researchers analyzed 21 randomized controlled trials for the study that appears in today's Journal of the American Medical Association (JAMA). Elderly patients undergoing hip or knee surgeries were most susceptible, with a 30 percent lower risk of infection when fewer transfusions ...

Medication does not help prevent ED following radiation therapy for prostate cancer

2014-04-01

Among men undergoing radiation therapy for prostate cancer, daily use of the erectile dysfunction drug tadalafil, compared with placebo, did not prevent loss of erectile function, according to a study in the April 2 issue of JAMA. Erectile dysfunction (ED) is a common condition resulting from many causes, including prostate cancer treatment. An estimated 40 percent of men report ED after radiation therapy, and half of all men use erectile aids following this therapy. Tadalafil is used to treat erectile dysfunction after prostate cancer treatment, but its role as a preventive ...

Outcomes of administering blood transfusions to patients with lower levels of hemoglobin

2014-04-01

Restricting red blood cell (RBC) transfusions among hospitalized patients to those with hemoglobin (the iron-containing protein in RBCs) measures below a certain level is associated with a lower risk of health care-associated infections, according to a study in the April 2 issue of JAMA. Efforts to prevent health care-associated infection are among the priorities for the U.S. Department of Health and Human Services. The estimated annual direct medical costs of health care-associated infections to U.S. hospitals ranges from $28 billion to $45 billion, with about 1 in ...

The potential conflict of interest for leaders of AMCs serving on pharmaceutical boards

2014-04-01

About 40 percent of pharmaceutical company boards of directors examined had at least one member who held a leadership position at an academic medical center, with annual compensation for these positions averaging approximately $300,000, according to a study in the April 2 issue of JAMA. "Financial relationships between the pharmaceutical industry and physicians have come under increased scrutiny. Less attention has been paid to relationships between industry and the leadership of academic medical centers (AMCs), who wield considerable influence over research, clinical, ...

Experts question routine mammograms in elderly

2014-04-01

Doctors should focus on life expectancy when deciding whether to order mammograms for their oldest female patients, since the harms of screening likely outweigh the benefits unless women are expected to live at least another decade, according to a review of the scientific literature by experts at UCSF and Harvard medical schools. National guidelines recommend that doctors make individualized screening decisions for women 75 and older. But the analysis, published online Tuesday in JAMA (March 31, 2014), concluded that since this age group was not included in mammography ...

Night owls, unlike early birds, tend to be unmarried risk-takers

2014-04-01

Women who are night owls share the same high propensity for risk-taking as men, according to a recent study by a University of Chicago professor. The research suggests that sleep patterns are linked with important character traits and behavior, said study author Dario Maestripieri, professor in Comparative Human Development. Night owls—people who tend to stay up late and wake up late in the morning—are different in many important ways from early risers, he found. "Night owls, both males and females, are more likely to be single or in short-term romantic relationships ...

Like hand-washing, blood transfusions linked to infections

2014-04-01

Blood transfusions are among the most common treatments for hospitalized patients nationwide, but doing them less often reduces infection rates by nearly 20 percent, according to a study in the Journal of the American Medical Association co-authored by Neil Blumberg, M.D., professor at the University of Rochester School of Medicine and Dentistry. As director of transfusion medicine and the blood bank at UR Medicine, Blumberg for more than 25 years has been investigating how to make blood transfusions safer. The JAMA study is the first to show conclusively, through a study ...

A protein could be a key weapon in the battle of the bulge

2014-04-01

Bethesda, MD (April 1, 2014)— More than one-third of people in the US are obese. Obesity and its related health problems—including high blood pressure, high cholesterol, diabetes, insulin resistance, and belly fat—affect so many, yet effective treatments are very few. In a new study, Simon Musyoka Mwangi and colleagues tested whether higher levels of a certain protein help fight the weight gain and health problems caused by eating the wrong foods. Glial cell line-derived neurotrophic factor—or GDNF for short—is a protein integral to keeping the body's systems in balance ...

August Issues of APA journals feature new research on psychiatric genetics, telehealth prescribing of controlled substances, mental health advocacy, and more

Well-rested flies

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: