Meeting Abstract

P3.98  Thursday, Jan. 6  Exploring the effects of the glutamate agonist BMAA on central and peripheral motor control in Drosophila melanogaster. MEKDARA, NT; CHOUDHURY, S; MEKDARA, PJ; GOODARZI, A; MAZLOOMI, F; ADAM, M; BERG, O; GOTO, JJ; MULLER, UK*; CSU Fresno umuller@csufresno.edu

Glutamate is an important neurotransmitter in the insect nervous system: it is the excitatory neurotransmitter at the neuromuscular junctions (NMJ) and acts as a neuromodulator in the central pattern generator at the central complex. We explore how the glutamate agonist BMAA (beta-methylamino alanine) affects the walking behavior of adult fruit flies. Flies were fed BMAA at three different concentrations for 4 days. We recorded their walking behavior for 10 minutes each day to quantify differences in walking distance, speed, bout duration, bout frequency, and climbing ability. Based on results from previous studies, we predicted that BMAA would increase walking speed and bout frequency, but not bout duration. BMAA should also cause muscle tremors due to its effect at the NMJs. After 1 day of treatment, we observed no significant loss of motor ability in flies treated with the two lower doses, but did show an increase in walking speed and/or walking activity. After 3 days of treatment, the low-dosage flies began to show signs of losing motor ability: walking distance and speed dropped, and the flies showed increased missteps in attempts to walk onto the ceiling. High-dosage flies have a low walking speed, distance and bout duration already after day 1. We concluded that activity parameters that are controlled centrally, such as walking bout frequency and duration, show a significant response to BMAA at lower doses than motor ability parameters that are controlled also by the peripheral nervous system, such as walking distance and climbing ability. We also found that not only bout frequency, but also walking bout duration increased in the treated flies. This finding contradicts predictions about central pattern generator’s role in controlling walking activity.