Fig. 4. fat-3 mutant animals display functional and not morphological neuronal defects. (A,B) Serotonergic neurons visualized with GFP under the control of a tryptophane hydoxylase promoter (tph-1), which is expressed in serotonergic neurons (Sze et al., 2000). (A) An HSN motor neuron in proximity of the vulva. Bars, 5 µm. (B) Serotonergic neurons in the head. Images shown are projections of confocal xy sections. Bars, 10 µm. (C) Exogenous arachidonic acid (AA) restores wild-type movement in adult fat-3(lg8101)/fat-3(qa1811) mutant animals within 48 hours. ^*P=0.0017 versus wild-type animals. Data is plotted as mean ± s.e.m.