The questions of how a large population of neurons in the brain functions, how synchronized firing of neurons is achieved, and what factors regulate how many and which neurons fire under different conditions form the central theme of this book. Using a combined experimental-theoretical approach unique in neuroscience, the authors present important new techniques for the physiological reconstruction of a large biological neuronal network. They begin by discussing experimental studies of the CA3 hippocampal region in vitro, focusing on single-cell and synaptic electrophysiology, particularly the effects a single neuron exerts on its neighbors. This is followed by a description of a computer model of the system, first for individual cells then for the entire detailed network, and the model is compared with experiments under a variety of conditions. The results shed significant light into the mechanisms of epilepsy, electroencephalograms, and biological oscillations and provide an excellent test case for theories of neural networks.