Meeting Abstract

P2.54  Thursday, Jan. 5  Quantifying the Locomotory Capabilities of Drosophila through a Novel Lenticular Arena GOODARZI, Athena*; MEKDARA, Prasong j.; SOLTANI, Ana; BERG, Otto; GOTO, Joy J; MULLER, Ulrike K.; Cal. State Univ. Fresno; Cal. State Univ. Fresno; Cal. State Univ. Fresno; Cal. State Univ. Fresno; Cal. State Univ. Fresno; Cal. State Univ. Fresno

As toxicological screenings become widespread because of legislation requiring environmental impact studies and risk assessment to human health, Drosophila (fruit flies) have become the invertebrate model organism of choice. Drosophila are also an important model organism for mutational and genetic analysis. Screening assays have been developed to assess mortality, reproduction, or behavioral competence. In this study, we developed a new assay to assess locomotor competence. We developed a circular walking arena with a lenticular floor and a flat cover, so the slope of the floor increases gradually from the center to the edge of the arena. The arena is 75 mm in diameter and 7 mm high. Drosophila are negatively geotactic – they climb as high as possible. We tested whether our arena can detect subtle differences in walking ability by treating adult Drosophila with an environmental neurotoxin that is known to cause Parkinson’s like symptoms in humans. This neurotoxin is a glutamate-agonist, which should cause insect muscles to contract involuntarily. We therefore expect this toxin to cause loss of fine motor control in fruit flies. We quantify the climbing ability of 40 flies (10 control, 30 treated with three different doses) for 10 minutes per day over three consecutive days. We use custom-made software (Ctrax), student-developed MATLAB routines and manual behavioral scoring to track the flies in the arenas. Our experiments show that the lenticular arena not only detects a loss in climbing ability, like the tap-down assay. But it also enabled us to show that BMAA causes an increase in activity levels despite the loss of motor ability. So the lenticular arena allowed us to detect more complex effects of the neurotoxin than the tapdown.