Fig. 1

Acetylcholine induces tentacular contractions. A Contractile response to 0 µM–25 mM acetylcholine in 3-month-old polyps. The first response to acetylcholine occurred at 500 µM acetylcholine with 33.6 ± 2.4% of animals contracting their tentacles but was not significantly different than the controls (p = 0.339). At 1 mM, tentacular contractions occurred in 12 ± 3.97% of polyps tested. At 5 mM, tentacular contractions occurred in 18 ± 10.82% of polyps. Tentacular contractions occurred in 88 ± 1.42% of polyps treated with 10 mM and 85.9 ± 5.63% of polyps treated with 25 mM acetylcholine. Tentacular contractions observed at 10 mM and 25 mM were statistically significant from contractions observed polyps treated with control and lower concentrations of acetylcholine (p ≤ 0.05). B–D Single frame images from movies showing tentacular response to the addition of Nematostella growth medium. E–G Single frame images from movies showing tentacular response to the addition of 10 mM acetylcholine (F), and the subsequent relaxation that occurs after treatment (G). Response to acetylcholine is not significantly different (p = 0.196) between 13 day postfertilization (13 dpf), 2-month post fertilization (2 mpf), or 3-month postfertilization (3 mpf) old polyps (H). In all images, oral is to the left. These data were calculated using a one-way ANOVA. A Contractile response to 0 µM–25 mM acetylcholine in 3-month-old polyps F_7,18= 53.7, p < 0.001; (H) Response to acetylcholine at different timepoints F_3,8= 1.98, p = 0.196. Each experiment was performed N ≥ 3 times with an n ≥ 8/replicate. Points that do not share letters in (A) are statistically different from each other. (mpf) month postfertilization. (dpf) day postfertilization