NMDA Antagonists Inhibit Cortical Spreading Depression, But Accelerate the Onset of Neuronal Depolarization Induced by Asphyxia
Cortical spreading depression (SD) is a transient massive change of the local cortical microenvironment, which spreads over the cortex at a rate of approximately 3 mm/min. Asphyxia can facilitate the elicitation of SD. It has been proposed that release of glutamate may play an important role in SD1 and hypoxia. Glutamate activates the N-methyl-D-aspartate (NMDA), quisqualate and kainate receptors. We investigated whether the NMDA receptor is involved in SD during normoxia using the non-competitive NMDA antagonists ketamine, phencyclidine and MK-801 and the competitive NMDA antagonist 2-amino-7-phosphonoheptanoate (2-APH). Additionally, we tested whether NMDA antagonists affect the DC and ionic changes during asphyxia.