Formation of synapses and the changes in their connections during life are the basis for learning and memory and recovery from brain disease or injury. Much interest has been focused on how synapses function at the molecular level, while the cell-cell interactions controlling the formation receive far less attention. This book expands the scope of inquiry beyond the synaptic cleft to provide a comprehensive insight into how intercellular signalling enables neurons to communicate beyond the synapse, and to interact with other cells in the brain to alter synaptic connections appropriately....