Different arthropod species have different behaviors -- spiders spin webs, centipedes capture prey with their fangs, and bees perform a waggle dance to tell their nestmates where to find the best flowers. These behaviors are "hard-wired" -- each spider, centipede, or bee carries the information for its behaviors in its genes.

How do a bunch of genes encode a complex behavior?

To answer this question, we are studying the Drosophila LARVAL CRAWLING (DLC) circuit.

(Click below for Quicktime movies of larval crawling...)

By studying this simple locomotion behavior in the larvae (or "maggots") of Drosophila, we want to understand how genes provide the developmental cues that allow a neural circuit to wire up properly, and also how genes give specific neurons the ability to play different roles in the activity of a behavioral circuit.

Crawling involves 3 SYSTEMS working together:

MUSCLES

A criss-crossing pattern of muscles is repeated in each segment along the larva. The larva crawls forward by sending a wave of muscle contractions from the tail up to the head. The muscles are tagged with GFP, and when the muscles contract the fluorescence looks brighter.

CENTRAL NERVOUS SYSTEM

The CNS of the larva is the equivalent of our brain and spinal cord put together. The CNS is very small compared to the body of the larva, but it contains thousands of neurons that controls the patterns of crawling and other behaviors.

PERIPHERAL NERVOUS SYSTEM

The PNS includes all the sensory systems of the larva. Dozens of sensory cells under the skin in each segment provide feedback to the larva that helps it regulate crawling or find a more attractive place in the food.