Example of Helix culture manipulated with 5-HT applications. Each line represents a time-point of recordings (i.e., 6, 24, 36, 48, 54, 72 hours after plating). In the first column, the development of the neurite arborizations is indicated (scale bar is 200 μm). The three columns of raster plots as in Figure 2. Red and blue lines indicate C1 and B2 neurons respectively. Scale bar is 10 s.