Vol. 60, Issue 4, 808-815, October 2001

Activation of Metabotropic Glutamate Receptor Subtype 1/Protein Kinase C/Mitogen-Activated Protein Kinase Pathway Is Required for Postischemic Long-Term Potentiation in the Striatum

Paolo Calabresi, Emilia Saulle, Girolama A. Marfia, Diego Centonze, Roseann Mulloy, Barbara Picconi, Robert A. Hipskind, François Conquet, and Giorgio Bernardi

Clinica Neurologica, Dipartimento di Neuroscienze, Università di Roma Tor Vergata, Roma, Italy (P.C., E.S., G.A.M., D.C., B.P., G.B.); Istituto di Ricovero e Cura a Carattere Scientifico Fondazione Santa Lucia, Roma, Italy (P.C., B.P., G.B.); Institut de Génétique Moléculaire, Centre National de la Recherche Scientifique-Unité Mixte Recherche 5535, Montpellier, France (R.M., R.A.H.); and Glaxo Wellcome Experimental Research, Institut de Biologie Cellulaire et de Morphologie, Lausanne, Switzerland (F.C.)

Excessive stimulation of glutamate receptors is believed to contribute substantially in determining neuronal vulnerability to ischemia. However, how this pathological event predisposes neurons to excitotoxic insults is still largely unknown. By using electrophysiological recordings from single striatal neurons, we demonstrate in a corticostriatal brain-slice preparation that in vitro ischemia (glucose and oxygen deprivation) activates a complex chain of intracellular events responsible for a dramatic and irreversible increase in the sensitivity of striatal neurons to synaptically released glutamate. This process follows the stimulation of both N-methyl-D-aspartate and metabotropic glutamate receptors and involves the activation of the mitogen-activated protein kinase ERK via protein kinase C. This pathological form of synaptic plasticity might play a role in the cell type-specific neuronal vulnerability in the striatum, because it is selectively expressed in neuronal subtypes that are highly sensitive to both acute and chronic disorders involving this brain area.