Selective enhancement by basic fibroblast growth factor of NMDA receptor-mediated increase of intracellular Ca2+ concentration in hippocampal neurons.

The short-term effect of bFGF on intracellular Ca2+ concentration ([Ca2+]i) of hippocampal neurons was investigated using dissociated cell cultures. Changes in [Ca2+]i were measured by microfluorometrically monitoring the fluorescence intensities from individual neurons loaded with fura-2. Perfusion of bFGF (20 ng/ml) alone did not affect the basal level of [Ca2+]i in hippocampal neurons, but clearly enhanced the [Ca2+]i increase induced by NMDA. Quisqualate or KCl-induced [Ca2+]i increase was not influenced by bFGF. These results suggest that bFGF selectively enhances the NMDA receptor-mediated response in hippocampal neurons.