Genetic Dissection of the Neural Circuit Underlying Cold Nociceptive Behavior

Undergraduate #16
Discipline: Biological Sciences
Subcategory: Genetics

Yari Mosley - University of Arkansas at Pine Bluff
Co-Author(s): Atit Patel and Daniel N.Cox

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Do Class III dendritic arborization neurons play a major role in detection and response to noxious cold stimuli? Which interneurons are responsible for the cold evoked behavior? Class III neurons are specifically connected to motor neurons on the outer body wall of Drosophila larvae, contributing to the hypothesis that these neurons are integral for nociceptive cold response. However while it has been extensively studied the impact of Class II, IV, and I systems on nociception, Class III neurons have not been studied in this capacity before. To test this hypothesis, we completed 100 crosses of Gal4 driver males with UAS-TNT-E2 virgin females (Tetanus Toxin variant), to produce 30 larvae per cross that should carry an inhibitory gene, causing the Class III and bordering motor neurons to disconnect. These crosses resulted in at least 12-15 out of each group of 30 larvae to not exhibit usually contraction behavior when exposed to temperatures of 5 degrees Celsius and below (noxious cold). Removing the connection between Class III and motor neurons resulted in the animal not contracting in response to cold, providing evidence consistent with the hypothesis, that Class III neurons are important for cold nociceptive responses. In relation to previous studies done on noxious heat response, a similar variant was used on Class IV neurons to test importance to usual rolling response, providing evidence supporting Class IV neurons integral position. However, the result given in the current experiment could be because of outside stimuli affecting the larvae, such as dryness, moistness, vibrations, or light. These recent discoveries in the development of the Drosophila larval neurological system provide important insight into human neurological morphology and development.

Funder Acknowledgement(s): The funds for my research project was provided by the NIH organization.

Faculty Advisor: Anissa Buckner, bucknera@uapb.edu

Role: I completed all research involved in this experiment.