Conditional modification of behavior in Drosophila by targeted expression of a temperature-sensitive shibire allele in defined neurons.

Behavior is a manifestation of temporally and spatially defined neuronal activities. To understand how behavior is controlled by the nervous system, it is important to identify the neuronal substrates responsible for these activities, and to elucidate how they are integrated into a functional circuit. I introduce a novel and general method to conditionally perturb anatomically defined neurons in intact Drosophila. In this method, a temperature-sensitive allele of shibire (shi(ts1)) is overexpressed in neuronal subsets using the GAL4/UAS system. Because the shi gene product is essential for synaptic vesicle recycling, and shi(ts1) is semidominant, a simple temperature shift should lead to fast and reversible effects on synaptic transmission of shi(ts1) expressing neurons. When shi(ts1) expression was directed to cholinergic neurons, adult flies showed a dramatic response to the restrictive temperature, becoming motionless within 2 min at 30 degrees C. This temperature-induced paralysis was reversible. After being shifted back to the permissive temperature, they readily regained their activity and started to walk in 1 min. When shi(ts1) was expressed in photoreceptor cells, adults and larvae exhibited temperature-dependent blindness. These observations show that the GAL4/UAS system can be used to express shi(ts1) in a specific subset of neurons to cause temperature-dependent changes in behavior. Because this method allows perturbation of the neuronal activities rapidly and reversibly in a spatially and temporally restricted manner, it will be useful to study the functional significance of particular neuronal subsets in the behavior of intact animals.