• October 2016

Neural Circuits Controlling Motor Sequences

Animals chose among a wide range of behaviors depending on current sensory cues, internal state, and past experience.  They execute these behaviors by coordinating a limited repertoire of motor neurons driving muscles in their limbs.  Since they cannot perform all behaviors at once, they must select among choices.  A changing series of choices can result in a behavioral sequence.  We are interested in how animals make these choices, both at an algorithmic level and in how specific neural circuits in the brain execute the required computations.

How does the nervous system select and sequentially execute motor programs? 

We have developed fruit fly grooming as a model to understand motor program selection. Grooming is a complex behavioral sequence assembled from simpler motor subroutines executed in order.  When a fly is completely covered in dust, it cleans itself by an ordered series of leg movements targeted first to the head, then abdomen, then wings, and then thorax.  We study how the fly’s brain coordinates this progression using:

  • quantitative behavioral analysis
  • genetic perturbation of specific neurons, and
  • imaging neural activity during grooming

The genetic reagents available in the fly make it possible to dissect the relevant neural circuits completely at single cell resolution.  By discovering the organizational strategies, circuit motifs and activity patterns that produce the fly grooming sequence, we hope to provide insights into universal mechanisms for the ordered execution of competing behaviors.