 |
PAGE 2 OF 2
In the first official experiment performed with their new apparatus, for example, Vivek’s group focused on the fly’s optic lobes, brain regions that process vision.
As they describe in the July 22 issue of Current Biology, the researchers found that optic lobe neurons tune their responses according to the fly’s interaction with the environment. “The neuron changes completely when the fly walks—it becomes more sensitive to higher speeds of motion,” Chiappe explains.
In future experiments, the team will use the setup to record from different cell types. They’re also trying to figure out how to use different kinds of visual stimuli—such as pictures of objects with long edges—to prod the insects to walk in certain directions. “We’re basically watching flies walk on a ball and wondering how visual signals getting into their brain are transformed into actions,” Chiappe says. What they are finding out is anything but simple.
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
Slow and Steady Does It
If you’ve ever taken a close look at fruit flies hovering around your bananas, you can imagine the daily frustration of scientists who work with these tiny creatures. Manipulating Drosophila requires patience, persistence, and—above all—extremely steady hands. (Vivek, in fact, has given up coffee.)
“You can’t accidentally cut off a leg, or else you can’t measure their walking response. If you pull on a muscle the wrong way, the fly will get ticked off,” says Michael Reiser. Perturbed flies and their flailing limbs are all but impossible to mount on a tiny microscope platform.
One of the long-term goals of their collaboration is creating more automated devices to reduce this human error. “Right now, it’s just good old manual dexterity,” Reiser says. “We want to make it more like a surgery, where special tools can assist you.”
Unfortunately, the dearth of manual expertise has steered many other fly labs away from this kind of work. “A lot of people are turned off by the overwhelming technical challenge,” he says, “so it’s really important to demonstrate that these experiments are possible.”
Now that they’ve demonstrated that the new method can measure brain patterns during fly walking, the team hopes other labs will use it to probe other aspects of behavior. To that end, they have posted detailed instructions, photographs, and videos of their technique on an open-source website, www.flyfizz.org.
--- V.H.
|
|
|
|
|
|
|
|
|
|
|
|
|
Go Back
