Abstract
Locomotory behavior (motility) is a vital importance in animals. We examined the effects of ionizing radiation (IR) on locomotory behavior using Caenorhabditis elegans, and reported an IR-induced reduction of locomotory rate in the absence of food [1], [2]. In the previous experiments, wild-type animals were irradiated with γ-rays in the whole body, and measured the motility using 'body bends' (the number of bends in the anterior body region at 20-s intervals) [3]. However, the IR-induced effects in the central and posterior body region were not evaluated by the body bends. Therefore, in the present study, to investigate the IR-induced effects in more detail, we propose a method evaluating the motility of whole body by using the video-based analysis. Animals were irradiated with graded doses of 60Co γ-rays (< 1000 Gy) at a dose rate of 32 Gy/min. Immediately after irradiation, we video-recorded the animals, and analyzed the trajectories and bends at 17 points of the body. The proposed method provides some novel insight about the IR-induced changes on C. elegans's locomotion. In the presentation, we will show results of the analyses based on the conventional and novel evaluation standards, and would like to discuss about the importance of considering of an adequate standard to evaluate IR-induced effects. [1] Sakashita, T., et al. (2008) J. Radiat. Res. 49: 285-291. [2] Suzuki, M., et al. (2009) J. Radiat. Res. 50:119-125. [3] Sawin, E.R., et al. (2000) Neuron 26:619-631.
