B103 neuroblastoma cells overexpressing EGFP-LPA1 receptor were treated with (A, D) vehicle (0.1% fatty acid free bovine serum albumin), (B) LPA, or (C, E) (S)-17. Cells were then fixed and stained with phalloidin and DAPI, and analysed under fluorescence microscopy for visualization of LPA (green), cell morphology (red) and nuclei (blue). The number of cells with retracted neurites was counted and expressed as the percentage of the total number of cells (F). The data shown correspond to the mean±SEM of the number of cells counted in two independent experiments and three different slides per experiment. *, p<0.05; **, p<0.01 vs BSA (Student’s t test). Samples were imaged under the same conditions using a Zeiss fluorescence microscope (A-C, bars 100 μm) or Zeiss fluorescence confocal microscope (D, E, bars 10 μm).