ABSTRACT
Glutamate receptors can be broadly classified as two types, ionotropic and metabotropic. The use of brain slices for biochemical assays has also aided in the characterization of metabotropic glutamate receptors in the hippocampal formation. Evidence that excitatory amino acid-stimulated phosphoinositide hydrolysis is mediated by a distinct G-protein-coupled glutamate receptor comes from a number of biochemical studies conducted in rat hippocampal slices. l-Glutamate exerts its physiological actions by acting on multiple populations of receptor proteins that are clearly distinguished by their pharmacological and molecular characteristics. Glutamate receptors can be broadly classified as two types, ionotropic and metabotropic. It is important to have relatively simple and well-defined in vitro systems for distinguishing the activity of compounds acting at these glutamate receptor types. Ionotropic glutamate receptors exist as heteromeric protein complexes that are composed of multiple subunit proteins. One of the primary ways used to describe the functions of ionotropic glutamate receptors in hippocampus has been to study agonist-induced electrophysiological responses.
