Animals have the ability to sense, process and respond to signals important for navigating their environment. These behavioral responses to external signals rely on the nervous system?s ability to detect and integrate these signals. A continued exposure to a stimulus over time results in the animal diminishing its behavioral response, a phenomenon referred to as adaptation. Adaptation is critical for an organism to detect and respond to a new, possibly threatening, stimulus while in the presence of a continuous, existing stimulus. Modification of neural connections called synapses is thought to form the basis for adaptation, and other simple forms of learning. A central question regarding this process is how the nervous system modifies its connections to produce this diminished response. The goal of this project is to identify the gene products (proteins) mediating adaptation. The project will utilize the nematode, Caenorhabditis elegans (C. elegans), a well-characterized model organism for identifying genes involved in behavior. A method for measuring adaptation of the egg-laying behavior to long-term exposure to the neurotransmitter, serotonin, has been developed and will be used to examine the synaptic connections required for adaptation as well as to generate mutant worms defective in adaptation of this egg-laying response. Isolation of mutant worms defective in adaptation will provide a means to identified genes involved in this behavior. Because serotonin is an important neural signal that mediates behavioral responses such as feeding, mating behavior and aggression, this research may provide insight into how other serotonin-dependent behaviors are altered by continual stimulation. The project will have a broader impact on education through the applicant?s participation in the NSF-sponsored STEP program, which serves to increase participation and retention of students, including under-represented groups in the sciences. In addition, the applicant utilizes research in C. elegans in teaching molecular biology, genetics and neurobiology.
