Effects of l-daurisoline on quinolinic acid-induced Ca2+ influx in hippocampus neurons in freely moving rats.

In freely moving rats, hippocampus neuronal extracellular calcium concentration (Ca2+)e and seizures were investigated. Application of quinolinic acid 156 nmol (exciting N-methyl-D-aspartate receptor, NMDA) to dorsal hippocampus elicited a decrease in (Ca2+)e by 48 +/- 5% in the infusion area and produced a characteristic abnormal EEG. l-Daurisoline dramatically prevented the reduction in (Ca2+)e, but not seizures (EEG). The results suggest that NMDA-operated calcium channels, but not NMDA-receptors, are involved in the effects of l-daurisoline on Ca2+ influx observed.