Activation of TH-GAL4-expressing neurons did not alter females' egg-laying preferences in general. A, Females with their TH neurons artificially activated continued to prefer laying eggs on the soft substrate in a firm versus soft assay. Positive Preference Index (PI) indicates a preference for the firm substrate. N = 31, 30, 22, 36, 34, 41 for columns, left to right. B, Activating the TH-GAL4 neurons increased egg-laying acceptance of a firm substrate that contained 150 mm sucrose. Positive PI indicates a preference for the firm and sweet (firmsweet) substrate. N = 15, 15, 28, 15, 14, 32 for columns, left to right. C, Females with inhibited TH neurons still preferred the plain substrate in the sucrose versus plain assay. Positive PI indicates a preference for the sucrose substrate. The following abbreviations are used: (1) tsh-GAL80, shiTS/+: tsh-GAL80/+; UAS-shibireTS/+ and (2) tsh-GAL80, TH > shiTS: tsh-GAL80/+; TH-GAL4/UAS-shibireTS. N = 15, 59, 59, 33, 60, 19 for columns, left to right. S, sucrose; P, plain.