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Similar Brain Chemicals Influence Aggression In Fruit Flies And Humans:

Serotonin is a major signaling chemical in the brain, and it has long been thought to be involved in aggressive behavior in a wide variety of animals as well as in humans. Another brain chemical signal, neuropeptide Y (known as neuropeptide F in invertebrates), is also known to affect an array of behaviors in many species, including territoriality in mice. A new study by Drs. Herman Dierick and Ralph Greenspan of The Neurosciences Institute in San Diego shows that these two chemicals also regulate aggression in the fruit fly, Drosophila melanogaster.

In a series of studies that used drug treatments and genetic engineering we have produced flies that make increased or decreased amounts of serotonin, or whose nerve cells that use serotonin or neuropeptide F are silent or inactive. Our investigations showed that the more serotonin a fly makes, the more aggressive it will be towards other flies. Conversely, presence of neuropeptide F has an opposite modulatory effect on the flies' behavior, reducing aggression. Serotonin and neuropeptide F are part of separate circuits in the brain, circuits which also differ to some extent between males and females. Male flies are much more aggressive.

Scientists Unlock Secret Of What Makes Plants Flower:

A protein acting as a long-distance signal from leaf to shoot-tip tells plants when to flower, says new research published in Science Express. The study reveals the likely mechanism by which the Arabidopsis plant flowers in response to changes in day length. Earlier research had shown that plants' leaves perceived seasonal changes in day length, which triggers a long-distance signal to travel through the plant's vascular system from the leaf to the shoot apex, where flowering is induced. However, the identity of the long-distance signal remained unclear.

Honey Bee Die-off Alarms Beekeepers, Crop Growers And Researchers:

An alarming die-off of honey bees has beekeepers fighting for commercial survival and crop growers wondering whether bees will be available to pollinate their crops this spring and summer. Researchers are scrambling to find answers to what's causing an affliction recently named Colony Collapse Disorder, which has decimated commercial beekeeping operations in Pennsylvania and across the country.

Why Don't Mothers' Bodies Reject Their Fetus?:

The immune system is designed to attack anything that is not the body's own tissues, such as pathogens and genetically nonidentical organ transplants, so why does the maternal immune system not attack a developing fetus? Several answers to this question are provided by a new study of mice from researchers at New York University School of Medicine.

Potential New Drug Against African Sleeping Sickness:

Researchers have shown that a drug that was extensively tested against cancer may also qualify as a new drug against African sleeping sickness. African sleeping sickness, a disease marked by fever, headaches, and sleepiness, is caused by a parasite that is transmitted to humans through tsetse fly bites. The parasite escapes destruction by the host immune system because it is surrounded with a "coat" made of proteins that constantly change. But the parasite may have a weakness: It contains very low amounts of cytidine triphosphate (CTP), a molecule essential for cell survival.