Posts tagged neuropeptide
Articles and news from the latest research reports.
Fighting Flies
When one encounters a group of fruit flies invading their kitchen, it probably appears as if the whole group is vying for a sweet treat. But a closer look would likely reveal the male flies in the group are putting up more of a fight, particularly if ripe fruit or female flies are present. According to the latest studies from the fly laboratory of California Institute of Technology (Caltech) biologist David Anderson, male Drosophilae, commonly known as fruit flies, fight more than their female counterparts because they have special cells in their brains that promote fighting. These cells appear to be absent in the brains of female fruit flies.
"The sex-specific cells that we identified exert their effects on fighting by releasing a particular type of neuropeptide, or hormone, that has also been implicated in aggression in mammals including mouse and rat," says Anderson, the Seymour Benzer Professor of Biology at Caltech, and corresponding author of the study. "In addition, there are some recent papers implicating increased levels of this hormone in people with personality disorders that lead to higher levels of aggression."
The team’s findings are outlined in the January 16 version of the journal Cell.
Drowsy Drosophila shed light on sleep and hunger
Scientists discover key function in molecule that regulates sleep, metabolism and hunger
Why does hunger keep us awake and a full belly make us tired? Why do people with sleep disorders such as insomnia often binge eat late at night? What can sleep patterns tell us about obesity?
Sleep, hunger and metabolism are closely related, but scientists are still struggling to understand how they interact. Now, Brandeis University researchers have discovered a function in a molecule in fruit flies that may provide insight into the complicated relationship between sleep and food.
In the October issue of the journal Neuron, Brandeis scientists report that sNPF, a neuropeptide long known to regulate food intake and metabolism, is also an important component in regulating and promoting sleep. When researchers activated sNPF in fruit flies, the insects fell asleep almost immediately, awaking only long enough to eat before nodding off again. The flies were so sleepy that once they found a food source, they slept right on top of it for days — like falling asleep on a giant hamburger bun and waking up long enough to take a few nibbles before falling back to sleep.
When researchers returned sNPF functions to normal, the flies resumed their normal level of activity, leaving behind their couch potato ways.
The researchers, led by professor of biology Leslie Griffith, concluded that sNPF has an important regulatory function in sleep in addition to its previously known function coordinating behaviors such as eating and metabolism.
"This paper provides a nice bridge between feeding behavior and sleep behavior with just a single molecule," says Nathan Donelson, a post doctoral fellow in Griffith’s lab and one of the study’s lead authors.
Neurons use neuropeptides to communicate a range of brain functions including learning, metabolism, memory and social behaviors. In humans, Neuropeptide Y functions similarly to sNPF and has been studied as a possible drug target for obesity treatment.
But scientists don’t fully understand how regulating neuropeptide function at specific times and in specific cells affects sleeping and eating. By studying sNPF in fruit flies, scientists can learn which cells, neurotransmitters and genes are involved in eating and sleeping; what processes turn on and inhibit the behaviors, and how sleep cells are relevant to hunger drive.
"Our paper makes a significant step into tying all these things together," says Donelson, "and that is extremely important down the road to our understanding of human health."
(Source: eurekalert.org)