INVESTIGATIONS ON THE ROLES OF CLASS 3 SEMAPHORINS IN THE ADULT HIPPOCAMPUS

Abstract

Class 3 Semaphorins are important guidance cues for the development of the embryonic nervous system. However, the roles of Semaphorins in the adult nervous system have not been characterized. This study uncovered the novel roles of Class 3 Semaphorins in promoting dendritic growth via a Cdk5-FAK pathway and in regulating cell positioning of newborn neurons in the adult hippocampus via the GSK3ß pathway. In addition, Sema3F/NRP2 signaling in the adult dentate gyrus is critical for contextual fear learning. This study sets the stage for future investigations on how regulation of Class 3 Semaphorins contributes to brain functions in different physiological and pathological states and could imply potential clinical applications.