FILOPODIA ON NEURONAL GROWTH CONES - MULTIFUNCTIONAL STRUCTURES WITH SENSORY AND MOTOR CAPABILITIES

Pathfinding decisions, as neuronal growth cones navigate their complex embryonic terrain are largely determined by the fan-shaped army of fi lopodia at the leading edge of the advancing growth cone. These sensor y/motor extensions of growth cones locally receive, process, and react to information from their environment. Recent advances in our Knowled ge of the mechanisms by which extracellular signals cause changes in t he concentration of the second messenger calcium and by which calcium affects growth cone function have provided substantial insights into t he chain of events occurring in filopodia that help guide growth cones to their appropriate targets.