Sets Up Lab
alumna Leslie Vosshall is head of the Laboratory of Neurogenetics
When Rockefeller alumna Leslie Vosshall came back to campus in
October, she wasnt just going to be working in a lab but running
it. Vosshall, head of the universitys new Laboratory
of Neurogenetics and Behavior, is trying to understand the molecular
basis of olfaction (the sense of smell) in the fruit fly. Scientists
know a lot about fruit fly behavior, but little is known about how
the flies recognize food sources.
As a graduate student, Vosshall worked in Michael Youngs
Laboratory of Genetics. "Mike Young made enormous strides in
understanding how genes impact behavior," says Vosshall. "In
the last 15 years, hes identified many of the important molecular
components that regulate the circadian clock. Remarkably, these
same components are now also showing up in the analysis of the vertebrate
clock." What she wants to do is apply the same sort of analysis
to olfactory behavior.
The sense of smell is very distinct from other sensory systems.
Olfactory systems are designed to detect stimulus quality and concentration
in the environment, a complex task considering that there are thousands
of different odors. Olfactory systems also appear not to be evolutionarily
related. "There's a dividing line at vertebrates," she
said. Nematodes and flies, for example, use different gene families
for olfaction. "The proteins have a similar structure but the
amino acid sequences are completely different. Nature found many
ways to solve the same problem."
The fruit fly Drosophila has very specific olfactory behavior
strategies. Like other insects, it is a specialist and has narrow
food interests. The fly has a repertoire of 61 odorant receptors,
which are distributed among different olfactory neurons in the antenna.
"Thats probably how you get specificity," she says.
Fruit flies love ethyl acetate, for example. Vosshall is looking
to associate particular receptors with their corresponding odorants,
and to understand how functional olfactory wiring patterns are established
One of Vosshalls goals is to understand why some odorants
lead to attraction and some to repulsion. She is also interested
in how odorants interact with olfactory neurons and how this interaction
is encoded in the brain to lead to stereotyped behaviors.
"A classic question in neurobiology is whether synaptic activity
is required for the development of functional synapses or whether
animals are genetically wired," says Vosshall. Using what she
calls "genetic trickery," her lab is silencing neurons
and allowing the flies to develop, then reactivating the neurons.
This allows the researchers to see whether a functional olfactory
system can form in the absence of activity.
Behavior is hard to study, she says, because it involves the interaction
of complex neural circuits. Her lab is now conducting studies with
larvae ("They live to eat") to try to determine the range
of odorants they respond to. The researchers hope to be able to
identify reproducible larval behaviors that can be the basis of
further genetic studies.
The fruit fly is an appealing study subject because it is relatively
simple, has robust olfactory behaviors, and can be genetically manipulated.
She notes that Assistant Professor Peter Mombaerts, head of the
Laboratory of Developmental Biology and Neurogenetics, is looking
at some of the same questions in mice. "Hopefully there can
be some cross-pollination," she says.
Vosshall is glad to be back on campus. "One great change,"
she says, "is a real commitment to junior faculty. President
Levine is actively recruiting and expanding."
Vosshall also appreciates how helpful the universitys administration
was in helping her set up her first lab. "The Rockefeller infrastructure
is a well-oiled machine," she says. Starting a new lab involves
dealing with Purchasing, Maintenance, Sponsored Programs and other
offices. "Everyone was incredibly helpful," she says.
"At other places, I think it can sometimes be more of a struggle.
Rockefeller is a real paradise for junior faculty.