10.1371/journal.pone.0224221.g008 Tapan Goel Tapan Goel Rui Wang Rui Wang Sara Martin Sara Martin Elizabeth Lanphear Elizabeth Lanphear Eva-Maria S. Collins Eva-Maria S. Collins <i>Hydra</i> response to 1mM linalool (L), 0.04% heptanol (H), 2% urethane (U), and 0.1% chloretone (C). Public Library of Science 2019 anesthetic Hydra studies vivo imaging transplantation experiments vivo studies monoterpenoid alcohol linalool light stimuli cell proliferation tissue manipulation head regeneration Hydra research Hydra regeneration teaching contexts animal health Hydra lines cell viability Linalool acts 2019-10-24 17:47:25 Figure https://plos.figshare.com/articles/figure/_i_Hydra_i_response_to_1mM_linalool_L_0_04_heptanol_H_2_urethane_U_and_0_1_chloretone_C_/10045046 <p>A. Percent length of anesthetized <i>Hydra</i> polyps compared to their natural state at 10min incubation. n = 10 animals per condition across 2 technical replicates. Anesthetized lengths similar to the average lengths in HM were recorded in linalool at 103% (87, 112; median (25<sup>th</sup> percentile, 75<sup>th</sup> percentile)), heptanol at 83% (71, 93) and urethane at 96% (88, 118), while chloretone-treated animals hyperextended at 133% (125, 153). B. Induction times across 2 technical replicates. Linalool n = 13, heptanol n = 14, urethane n = 13, chloretone n = 10. Linalool’s median induction time was 9 min (6, 9) (median (25<sup>th</sup> percentile, 75<sup>th</sup> percentile)) and thus significantly longer than that of heptanol at 6 min (4, 9), urethane at 5 min (4, 6) and chloretone at 5 min (3, 7). C. Recovery times across 2 technical replicates. Linalool n = 10, heptanol n = 8, urethane n = 12, chloretone n = 10. Median recovery time was 8 min (7, 17) for linalool, 11 min (7,15) for heptanol, 14 min (12, 26) for urethane and 13 min (7,15) for chloretone. (D-F) Pairwise statistical comparisons of data shown in A-C. Pink, red and dark red indicate a statistically significant difference at p<0.05, p<0.01 and p<0.001 respectively, determined using the Mann-Whitney U test between pairs of anesthetics. D. Comparison between percent length distributions. E. Comparison between induction time distributions. F. Comparison between recovery time distributions. G. Overview of the four anesthetics tested, scored on degree of immobilization, animal health following anesthesia, time to induce anesthesia, time to recover from anesthesia, morphology, and ease of use (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0224221#sec010" target="_blank">Methods</a>).</p>