Meeting Abstract

P2.109  Sunday, Jan. 5 15:30  Glutamate in the locomotory behaviors of Drosophila navigating around an obstacle SHINKAWA, N*; MEKDARA, PJ; WONG, TF; IQBAL, F; LENT, DD; MULLER, UK; California State Univ. Fresno; California State Univ. Fresno; California State Univ. Fresno; California State Univ. Fresno; California State Univ. Fresno; California State Univ. Fresno Shinkawa13@mail.fresnostate.edu

Drosophila melanogaster use vision to orient towards or avoid objects during walking and flight. To this end, visual input is transformed into new motor programs. In this study, we explore the underlying neural mechanisms by looking at the role of neurotransmitter systems in motor control. In insects, glutamate is a major excitatory neurotransmitter at the neuromuscular junction. There are also many glutamate receptors in the central nervous system, in particular in the central complex, a neuropil implicated in motor control. It has been shown that glutamate agonists have a significant effect on the fruit flies walking behavior and it’s control by the central complex. To examine the role of glutamate in the visual guidance of locomotory behavior, we have developed an arena in which we can observe and track individual wild-type and mutant flies as they perform normal vertical walking following a tap down protocol. As flies perform their vertical walking, they encounter an obstacle with high visual contrast, which requires them to maneuver around. We quantified the behaviors by investigating the distance from the barrier where the fly first initiates the turn, the time it takes to initiate to turn, and the radius at which it turns in order to explore how glutamate and the central complex function in mediating visually guided locomotion in Drosophila. We found that over expression of glutamate in the peripheral nervous system decreases the flies’ climbing ability and lowers the success rate in negotiating obstacles. Over expression of glutamate in the central complex is likely to cause an increase in walking speed without impairing the flies’ ability to maneuver around the obstacle