Cover photograph (Copyright © 2001, American Society for Microbiology. All rights reserved.): Live imaging of cytoskeletal dynamics in cultured NG108 neuronal cells expressing yellow fluorescence protein (YFP)-actin. The image shows a growth cone of an NG108 cell expressing YFP-actin pseudocolored in green, red, cyan, and yellow. YFP-actin was used to study neurite retraction in NG108 cells expressing the EphB2 receptor tyrosine kinase in response to stimulation with ephrin B1. (See related article on page 7429.)