Comparison of central effects produced by intracerebral injection of glutamic acid, quisqualic acid, and kainic acid

Icv glutamic acid (Glu), quisqualic acid (QA) and kainic acid (KA) significantly increased spontaneous activity of mice in photecell box, and induced dose-dependent rise of blood pressure in anesthetized rats. Their intensities were arranged in the order of KA greater than Glu greater than QA. In mice step-through test Glu 0.1 micrograms icv improved learning and memory; KA 1 ng had no evident effect; and QA 0.1 microgram impaired learning and memory, which were also confirmed by step-down test in normal mice. Therefore, the non-NMDA (N-methyl-D-aspartate) receptor subtype might be different from the NMDA receptor subtype in the action of learning and memory.