The flow of information coded as impulses through neuronal circuits is regulated not only by fast impulse-to-impulse synaptic transmission but also by slow synaptic transmission and modulation. The concept of slow synaptic responses and modulation emerged from studies on sympathetic ganglia, then was expanded to elucidate the detailed mechanisms in peripheral and central synapses. These key developments, along with recent progress in the field, are presented in this book. Major topics include the structure and function of single ion channels, neurotransmitter exocytosis, intracellular Ca2+ dynamics, plasticity, and gene expression. Each chapter opens with an explanatory review, followed by descriptions of recent findings in this rapidly evolving field. The book is thus a valuable resource for researchers working in the neurosciences, physiology, and pharmacology, from introductory to advanced levels.