Non-NMDA receptor mediates cytoplasmic Ca2+ elevation in cultured hippocampal neurones.

Microscopic fluorometry of cultured rat hippocampal neurones revealed that the intracellular concentration of Ca2+ ([Ca2+]i) rises in response to the activation of excitatory amino acid receptor (EAA-R), which included not only N-methyl-D-aspartate subspecies but also kainate and quisqualate subspecies of EAA-R. Each EAA-R mediated [Ca2+]i rise consisted of the components dependent on and independent of the activity of the voltage-dependent Ca2+ channel. The receptor-mediated voltage-independent [Ca2+]i rise may be related to the modulation of synaptic transmission efficacy.