Meeting Abstract

P1.167  Monday, Jan. 4  The effects of the glutamate agonist BMAA on the walking behavior of adult fruit flies KIM, HT*; SAITO, C; MEKDARA, NT; CHOUDHURY, S; GOODARZI, A; MAZLOOMI, F; SAKHA, T; SOLTANI, M; UBHI, S; CAO, Y; GOTO, JJ; MULLER, UK; California State University Fresno umuller@csufresno.edu

BMAA (beta-methylamino alanine) is an environmental neurotoxin that is suspected to be a glutamate agonist in insects. Previous studies have shown that glutamate is an excitatory neurotransmitter in the neuromuscular junctions of insects and a neuromodulator in the central complex that affects the central pattern generator for motor output. To explore the possible glutamate-agonist action of BMAA, we fed BMAA to adult fruit flies and quantified their locomotor behavior. We fed BMAA at three different concentrations for four consecutive days and recorded the flies’ behavior for 10 minutes each day. We observed that flies treated with the two lowest concentrations of BMAA walk faster and spend more time walking. The treated flies do not walk more often (which would correspond to shorter bouts of inactivity), but their walking bouts last longer than those of the control flies. These observations are consistent with BMAA acting as a glutamate agonist in the central complex that excites the central pattern generator. Previous studies on the temporal structure of walking behavior in fruit flies suggest that the central pattern generator regulates the inactive phase rather than the walking phase of activity periods. Such a control system should respond to BMAA with a shortening of the inactive period and leave the walking period unaffected. This prediction is not consistent with our observations of flies treated with the two low BMAA concentrations. At the highest concentration of BMAA, the flies show severe symptoms: they walk much less than the control group, exhibit tremors and experience difficulty standing and righting themselves after falling.