Chapter 16 - Postsynaptic Potentials and Synaptic Integration

Abstract

This chapter discusses the postsynaptic potentials (PSPs) and synaptic integration. PSPs in the central nervous system can be divided into two broad classes on the basis of mechanisms and the duration of potential. One class is based on the direct binding of a transmitter molecule(s) with a receptor–channel complex; these receptors are ionotropic. The other class of PSPs is based on the indirect effect of transmitter molecule(s) binding with a receptor. The receptors that produce these PSPs are metabotropic. The sign of the postsynaptic potential is determined by the relationship between the membrane potential of the postsynaptic neuron and the ion selectivity of the ionotropic receptor. The low threshold Na+ and Ca2+ channels can boost an excitatory postsynaptic potential (EPSP). It is considered that the spatial distribution of the various voltage-dependent channels, ligand-gated receptors, and metabotropic receptors is not uniform. Thus, each segment of the neuronal membrane can perform selective integrative functions. The system has an enormous capacity for the local processing of information and for performing logical operations.