Use of Daniovision™ to Measure Activity in 3rd Instar Drosophila melanogaster Larvae

Abstract

The noncompetitive GABAA receptor antagonist picrotoxin (PTX) decreases activity in 3rd instar Drosophila larvae (Eur J Neurosci, 2006). The purpose of these studies was to replicate the data obtained by Stilwell et al. using an automated data acquisition/data reduction system, Daniovision™ by Noldus.Larvae were extracted from food (Carolina Biologic Supplies 4‐24) in 20% sucrose at the 3rd instar stage. The larvae were randomly placed into vials containing vehicle (20% sucrose + 0.3% DMSO) or PTX from 0.03‐3 mM: n = 20‐30 larvae/treatment. After incubation for 2‐24 hr, individual larvae were placed in separate wells of a 6‐well culture plate previously coated with 2% agar, then placed in the Daniovision™ apparatus. The activity of each larva was digitized and recorded for 5 minutes using Ethovision software.PTX reduces 3rd instar larvae activity in a concentration‐dependent manner, consistent with findings reported by Stilwell et al. Incubation in 1 mM PTX for 4 or 24 hours decreased activity, with consistent reduction produced by 3 mM, variably by 0.3 mM, and never by 0.03 mM. PTX, 0.03‐3 mM, did not alter activity in a mutant strain, Rdl, known to have a point mutation in the PTX binding site on the GABAA receptor conferring a lower affinity for PTX.We have shown that an automated system can be used to quantify activity in 3rd instar Drosophila melanogaster larvae. As human observation and review of videos is not required, and multi‐well plates can be used, we have refined an in vivo high‐throughput screen for anti‐seizure compounds.Supported by funds from the University of Saint Joseph.