Spine architecture and synaptic plasticity
Many forms of mental retardation and cognitive disability are associated with abnormalities in dendritic spine morphology. Visualization of spines using live-imaging techniques provides convincing evidence that spine morphology is altered in response to certain forms of LTP-inducing stimulation. Thus, information storage at the cellular level appears to involve changes in spine morphology that support changes in synaptic strength produced by certain patterns of synaptic activity. Because the structure of a spine is determined by its underlying actin cytoskeleton, there has been much effort to identify signaling pathways linking synaptic activity to control of actin polymerization. This review, part of the TINS Synaptic Connectivity series, discusses recent studies that implicate EphB and NMDA receptors in the regulation of actin-binding proteins through modulation of Rho family small GTPases.
© 2005 Elsevier Ltd. Available online 8 February 2005. We thank members of the Kennedy laboratory, in particular Holly Beale, Edoardo Marcora and Luis Vazquez for helpful discussions. This work was supported by National Institutes of Health Grants 1F32 NS047894 (H.J.C.) and R01 NS28710 (M.B.K).