Molecular and cell biological analyses of mechanism of synaptic plasticity

虽然已知成纤维细胞生长因子信号在哺乳动物突触发育中诱导突触前分化，但目前尚不清楚成纤维细胞生长因子信号是否在突触后发育中起作用。在这里，我们报道了果蝇的成纤维细胞生长因子信号是神经肌肉接头突触后发育所必需的。果蝇的两个成纤维细胞生长因子配体，Pyramus和Thisbe，在神经元和肌肉中表达，而成纤维细胞生长因子受体无心，定位在突触后GluRIIA簇附近。突变体分析发现，成纤维细胞生长因子信号正向调节G1uRI1a在突触后部位的定位。此外，GluRIIA的表达也受成纤维细胞生长因子信号的转录调控。这些结果表明，在突触后NMJ发育过程中，果蝇成纤维细胞生长因子信号是谷氨酸受体表达的调节因子。

Although FGF signaling has been known to induce presynaptic differentiation in mammalian synaptic development, it remains unclear whether FGF signaling has a role in postsynaptic development. Here we report that Drosophila FGF signaling is required for the postsynaptic development of neuromuscular junctions. Two Drosophila FGF ligands, Pyramus and Thisbe, are expressed in neurons and muscles and a FGF receptor, Heartless, is localized in close proximity to postsynaptic GluRIIA clusters. Mutant analyses found that FGF signaling positively regulates G1uRI1A localization on postsynaptic sites. Moreover, GluRIIA expression is also controlled transcriptionally by FGF signaling. These results suggest that Drosophila FGF signaling is a regulator of Glutamate receptor expression in postsynaptic NMJ development.