Researchers at the California Institute of Technology (Caltech) have obtained the first recordings of brain-cell activity in an actively flying fruit fly.
The work—by Michael Dickinson, the Esther M. and Abe M. Zarem Professor of Bioengineering, with postdoctoral scholars Gaby Maimon and Andrew Straw—suggests that at least part of the brain of the fruit fly (Drosophila melanogaster) "is in a different and more sensitive state during flight than when the fly is quiescent," Dickinson says.
A paper describing the research appears February 14 in the advance online edition of Nature Neuroscience.
"Prior work on fruit flies has led to many important breakthroughs in biology. For example, the fact that genes reside on chromosomes and our understanding of how genes control development both emerged from experiments on fruit flies," Maimon says. "New research hopes to use these tiny insects to help determine how neurons give rise to complex behavior. This effort is helped by the fact that it is easy to manipulate the genes of fruit flies, but one problem remains: These insects are really, really tiny, which means it is very difficult to record from their brain during active behaviors such as flight.""Researchers have recorded the neural-cell activity of fruit flies before, but only in restrained preparations—animals that had been stuck or glued down," Dickinson explains. "Gaby was able to develop a preparation where the animal is tethered"—its head clamped into place—"but free to flap its wings." By slicing off a patch of the hard cuticle covering the brain, "we were able to target our electrodes onto genetically marked neurons," he says.
In particular, the researchers focused on those neurons in the fly's visual system that keep the animal flying stably during flight. "These cells basically help the fly detect when its body posture changes," Dickinson says. "The signals from these cells are thought to control tiny steering muscles that then change the pattern of wing motion and bring the animal back into equilibrium."
In their experiments, the researchers discovered that when the animals began to fly, the visual cells immediately ramped up their activity. "The neurons' responses to visual motion roughly double when the flies begin to fly, which suggests that the system is more sensitive during flight," Dickinson says. "The increase is very abrupt. It's not at all a subtle change, and so we suspect that there is a neurochemical quickly released during flight that sets the animal's brain in this different state."
Previous studies in locusts—which are far bigger and thus far easier to study—had suggested the existence of this effect. However, the genetics of locusts are not nearly as well understood as those of Drosophila, which has made it impossible to pinpoint the genetic basis for the phenomenon.
In Drosophila, Dickinson says, it now should be possible to "figure out specifically what causes the change in sensitivity. Is the system turned off when the fly is on the ground? What neurochemicals are involved? Now we can start to use the genetic tricks that are available in fruit flies to get a better idea of what is going on."
Maimon adds: "Our work on Drosophila is of general interest because sensory neurons in many species—including birds, rodents, and primates—change their response strength depending on the behavioral state of the animal, but why these changes in sensitivity take place is not entirely clear."
In addition, the researchers plan to use their tethered-flight system to record the activity of other types of cells, including olfactory and motor cells, to determine if these also behave differently during flight and when flies are at rest.
"The question is, 'Is the entire brain completely different in flight?'" Dickinson says. "We suspect that this phenomenon is not unique to the visual cells we have studied. Most cells care whether the animal is flying or not."
The work in the paper, "Active flight increases the gain of visual motion processing in Drosophila," was supported by the National Science Foundation and a Caltech Della Martin Fellowship.
Don't Give the Slightest Chance to Toxic Elements in Medicinal Products
23.03.2018 | Physikalisch-Technische Bundesanstalt (PTB)
North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
23.03.2018 | Event News
19.03.2018 | Event News
16.03.2018 | Event News
23.03.2018 | Life Sciences
23.03.2018 | Materials Sciences
23.03.2018 | Process Engineering