Hippocampal neurons expressing a green fluorescent protein (GFP) labeled postsynaptic density protein (green) were fixed and stained with rhodamine-phalloidin to visualize the location of cytoplasmic actin filaments (red) in the image presented above. In dendrites, the actin filaments are concentrated in the postsynaptic sites. The image was contributed by Shigeo Okabe from the Department of Anatomy and Cell Biology at the Tokyo Medical and Dental University in Japan.