Basic fibroblast growth factor modulates synaptic transmission in cultured rat hippocampal neurons.
Basic fibroblast growth factor (bFGF) is one of the effective growth factors that protect neurons against excitotoxic/ischemic injury and promote neuronal survival. In the present study, we examined the acute modulative effect of bFGF on synaptic transmission by monitoring spontaneous intracellular Ca2+ ([Ca2+]i) oscillation, the amplitudes of which reflect excitatory and inhibitory inputs. The hippocampal cells from embryonic day 18 rats were cultured for 11-14 days, and changes in [Ca2+]i of single neurons were measured by a microfluometrical technique with fura-2. The amplitude of spontaneous oscillation was decreased by 10 ng/ml bFGF, but not by nerve growth factor (10-1000 ng/ml). Acidic FGF (1000 ng/ml) had a weaker depressant effect. The effect of bFGF was counteracted by suramin. bFGF did not affect the increase in [Ca2+]i evoked by glutamate agonists, NMDA or kainate, indicating that glutamate receptors are not involved in the mechanism. This is supported by similar results that kainate-evoked current was not affected by bFGF. On the other hand, bicuculline masked the effect of bFGF on the Ca2+ oscillation. But GABA-evoked current was slightly decreased by bFGF. These results suggest the possible role of bFGF in modulating GABAergic rather than glutamatergic neurotransmission.
Tanaka
T
T
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
Saito
H
H
Matsuki
N
N
D000818:Animals; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects*; D016202:N-Methylaspartate / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013498:Suramin / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects*
D016222:Fibroblast Growth Factor 2; D013498:Suramin; D016202:N-Methylaspartate