EN
Recently we detected NMDA-induced 45Ca release in the rat dentate gyrus in vivo, attributable to the Ca2+ release (CICR) from the endoplasmic reticulum via ryanodine channels.In these experiments we compare expression of NMDA-evoked 45Ca release in the rat dentate gyrus (DG), CA1 and subiculum (SUB).The release of 45Ca was studied using in vivo prelabelled hippocampal regions.It was shown thet NMDA-induced 45Ca release, highly pronounced in the rat DG/CA4, is significantly less expressed in the CA1, whereas in the SUB and NMDA-evoked decrease in 45Ca efflux was noted.This corresponds to distribution of ryanodine receptors in the rat hippocampus, known from the literature.Expression of NMDA-evoked 45Ca release in these rat hippocampal regions which are enriched in ryanodine receptors supports our working hypothesis that CICR via ryanodine channels may be mainly responsible for 45Ca release.