Innovative Methods for Monitoring Locomotor Activity of Adult Drosophila Melanogaster in Space and Terrestrial Settings

Abstract

Examining the changes in locomotor activity of organisms such as drosophila in space can provide us with insight into the various potential effects of the foreign environment on astronauts and a variety of organisms. In some settings, such analysis can be impractical because of two major obstacles: first, the high-cost of cameras and devices needed for data collection over many experiment chambers, and, second, the wide bandwidth of the gathered video information. This addresses these two issues while still providing the necessary results for proper analysis of changes in locomotor activity in space.

The procedure can be divided into three major steps: acquisition and processing, logging, and low-bandwidth transmission of the fly movement data. The system used for monitoring the motion is a low-cost monochrome video camera imaging flies illuminated by a uniform light source of a desired wavelength or wavelengths. With this basic setup, still and continuous video imagery of the flies can be obtained. In order to reduce the required data bandwidth, a low-pass filter is used to extract the relevant fly movement signals from the video and make them available at a far lower bandwidth (few tens of Hz versus many MHz for raw video). This function is implemented on a very small circuit board. Following this processing step, the data will be logged or transmitted in real time.

Target results from such a system could include the following information about the flies: average mobility, leg and wing movement, and circadian rhythm information extracted from these measures.