Molecular physiology of kainate receptors

A decade ago, our understanding of the molecular properties of kainate rece ptors and their involvement in synaptic physiology was essentially null. A plethora of recent studies has altered this situation profoundly such that kainate receptors are now regarded as key players in the modulation of tran smitter release, as important mediators of the postsynaptic actions of glut amate, and as possible targets for the development of antiepileptic and ana lgesic drugs. In this review, we summarize our current knowledge of the pro perties of kainate receptors focusing on four key issues: 1) their structur al and biophysical features, 2) the important progress in their pharmacolog ical characterization, 3) their pre- and postsynaptic mechanisms of action, and 4) their involvement in a series of physiological and pathological pro cesses. Finally, although significant progress has been made toward the elu cidation of their importance for brain function, kainate receptors remain l argely an enigma and, therefore, we propose some new roads that should be e xplored to obtain a deeper understanding of this young, but intriguing, cla ss of proteins.