HOW IS THE GROOMING SEQUENCE ORGANIZED IN THE NERVOUS SYSTEM?
We use fruit flies for our research because of the cutting edge genetic tools that enable us to identify and manipulate the activity of neural circuitry that controls grooming. Using these tools, we test hypotheses about how the sequence is formed. The image below shows our current model that features independently evoked grooming movements that are activated in parallel by dust and selected serially through a hierarchical suppression mechanism.
Read more about this model in eLife. http://elifesciences.org/content/3/e02951
WHAT NEURAL CIRCUITS DRIVE GROOMING BEHAVIOR?
We use a number of cutting-edge circuit mapping techniques to determine the neural implementations of the grooming sequence. Grooming movements feature highly stereotyped, and often repetitive movements that sweep across the body surface, yet the execution of these movements must be flexible to fulfill particular needs. For example, the grooming duration over which a particular movement is performed can vary in response to particular stimuli such as displacement of the body part, debris, or parasites. Therefore, we also examine grooming neural circuitry as a model for understanding how movements are selected and flexibly controlled.
The neural circuit shown above controls grooming of the fruit fly antennae. Shown are antennal sensory neurons (blue), brain interneurons (yellow and red), descending neurons to the ventral nervous system that performs similar functions to the human spinal cord (green), and synaptic sites in the brain (grey). Read more about this circuit in eLife. http://elifesciences.org/content/4/e08758
HOW DO GENETIC DEFECTS CAUSE ABNORMALLY REPETITIVE BEHAVIORS?
Nervous systems produce produce complex sequential behaviors by sequentially selecting specific movements. Importantly, brain regions controlling this selection are implicated in disorders in which movements become abnormally repetitive, such as in obsessive-compulsive disorder (OCD). Because abnormally high levels of grooming occurs in animals with mutations in specific genes, grooming may serve as a model of repetitive movement disorders. We combine our tools for studying grooming neural circuitry with the genetic amenability of fruit flies to study how mutations in specific genes can lead to abnormally repetitive grooming.