The nervous system is an important system of the human body that coordinates its action by transmitting signals from one part of the body to another. It can be divided into the central and the peripheral nervous system. It consists of the brain, spinal cord and the nerves of the body. At the cellular level, the fundamental mechanism is that of the neuron, which transmits signals through axons that trigger the activation of neurotransmitters, which are then released at synapses. This signaling process involves a complicated molecular machinery, which allows the rapid electrical or chemical transmission of signals. Cells that receive a synaptic signal will be excited, inhibited or modulated. The organization of neural pathways, neural circuits and neural networks together build a functioning nervous system. Any abnormality in nervous function can manifest due to a genetic defect, infection, trauma, toxicity, or due to aging. This book provides comprehensive insights into the cellular and molecular basis of the working of the nervous system. It presents researches and studies performed by experts across the globe. It will serve as a reference to a broad spectrum of readers.