We next determined how ethanol affects C. elegans swimming in liquid. We found that ethanol inhibits swimming, although at a substantially higher dose than is required to inhibit crawling (Figure 5). While our results are in agreement with the first study of ethanol's effects on swimming in C. elegans (Morgan and Sedensky, 1995), they differ significantly from those reported by Mitchell et al. (2007), who used slightly different conditions. We found that the differences in our results from those of Mitchell et al. (2007) could be explained by the buffers used in our swimming analyses. Our study used Nematode Growth Media (NGM), which contains the same salts as the medium that animals are cultured on (Brenner, 1974), whereas the Mitchell study used Dent's buffer, a physiological saline normally used to record the electrical activity of dissected muscle (Avery et al., 1995). While the basal swimming behavior of worms in the two buffers was indistinguishable (data not shown), we observed a striking difference in behavior in the two buffers when ethanol was added. Figure 5a shows the time course of intoxication
