Figure 2

Serotonin decreases the migration speed of pyramidal neurons. (a, b) Confocal images showing that during the process of radial migration, 5-HT positive fibers (blue) are present in intermediate zone at E17.5 and E19.0, and that GAD65-GFP positive interneurons are not labeled by in utero electroporation. (c1) Epifluorescent time-lapse images taken from a 12-h time-lapse sequence showing that application of serotonin (400 μM) slows the migration of TOM+ neurons (arrowheads) in a P0.5 cortical slice, and that this effect is reversible after washing serotonin from the medium. Superposed color lines represent migratory tracks. (d) Graph showing the migratory distance traveled by TOM+ cells indicated in panel c2. Note that cells halt their migration during 5-HT application and gradually resume migration after the wash. (e, f) Graphs showing that the mean migratory speed of E17.5 TOM+ cells (e) and P0.5 TOM+ cells (f) significantly decreases after 5-HT application and is partially restored after 5-HT wash. White boxed area depicts a higher magnification image. ^**P<0.05, GFP, GAD65-GFP. Scale bars: 100 μm for a and b, 50 μm for c.