How is sensory information processed by neural circuits and used to select specific motor outputs? How are these functions of neural circuits encoded in the genome? These are the basic questions motivating our research. We address these questions by studying an animal that is capable of complex behavior and yet simple enough to allow systematic genetic manipulation of all parts of the neural circuitry.
Drosophila larvae sense and react to a wide range of stimuli and carry out many motor behaviors. These abilities are controlled by a relatively small number of neurons (about 10,000) that can be grouped into about 300 morphologically distinct neuron classes. Using the remarkable genetic toolkit generated by the Rubin lab at Janelia, we can selectively and reproducibly label and manipulate each of these neuron classes.
Our first goal is to investigate the effect of activating and inactivating single neuron classes on larval sensory processing, decision making, and motor production. For this purpose we have developed a set of automated high-throughput behavioral assays.
Our second goal is to target expression of genetically encoded Ca2+ indicators to specific neuron classes and to monitor Ca2+ signals in behaving animals. This should allow us to correlate Ca2+ signals in a neuron class with "perception" of specific stimuli and "generation" of specific reactions.
Our third goal is to identify molecules that are required in specific neuron classes for specific behaviors. Again, we can do this by selectively targeting RNAi (RNA interference) against candidate genes to specific neuron classes and testing the animal's performance in behavioral assays.
Together these approaches should provide insights into how the 300 neuron classes in this little animal generate a remarkable set of behaviors. Larval behavior may be simple when compared to human behavior, but we humans (despite the remarkable complexity of our nervous systems) do not yet understand even the behavior of a little larva, let alone that of humans. We hope that these studies of the little larva will bring us a step closer to understanding the neural and genetic basis of behavior in general.