1. Fibroblast growth factor-2 increases functional excitatory synapses on hippocampal neurons.
- Author
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Li, Ai‐Jun, Suzuki, Seigo, Suzuki, Masashi, Mizukoshi, Eiichi, and Imamura, Toru
- Subjects
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FIBROBLAST growth factors , *SYNAPSES , *HIPPOCAMPUS (Brain) , *RATS - Abstract
Abstract The effect of fibroblast growth factor-2 (FGF-2) on synapse formation was investigated using rat cultured hippocampal neurons. Treatment with FGF-2 (0.4–10 ng/mL) for 6 days enhanced synaptogenesis on these neurons by ∼50%, as determined by counting puncta immunostained for presynaptic- or postsynaptic-specific proteins. This enhancement was statistically significant, and was abolished by a specific inhibitor of mitogen-activated protein kinase (MAPK). The majority of neurons expressed FGF receptors (types 1–3) abundantly on the membrane of somata, dendrites, and growth cones, and in these regions phosphorylation of MAPK was enhanced after FGF-2 application. Furthermore, our experiments showed that the majority of synapses formed in cultures containing FGF-2 were positive both for presynaptic proteins and postsynaptic excitatory synapse-specific proteins, and that these synapses had a similar capacity to recycle the fluorescent styryl dye FM4-64 as those in the control culture. These results indicate that: (i) FGF-2 increases excitatory synapses on hippocampal neurons by activating MAPK activity through FGF receptors; and (ii) synapses formed in FGF-2-treated culture are capable of cycling vesicles. [ABSTRACT FROM AUTHOR]
- Published
- 2002
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