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Updated: Jun 1, 2026
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Utilizing Combined Methodologies to Define the Role of Plasma Membrane Delivery During Axon Branching and Neuronal Morphogenesis
Published on: March 16, 2016
Axonal filopodial asymmetry induced by synaptic target
Pan P Li1, Cheng Chen, Chi-Wai Lee
1Division of Life Science, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
Molecular Biology of the Cell
|May 27, 2011
Summary
Basic fibroblast growth factor (bFGF) signaling through neuronal FGF-receptor 1 (FGFR1) drives axonal filopodia formation. This process is crucial for nerve-muscle interactions and the establishment of neuromuscular junctions (NMJs).
Area of Science:
- Neuroscience
- Developmental Biology
- Cell Biology
Background:
- Neuromuscular junction (NMJ) assembly involves signaling between motor axons and muscle targets.
- Axonal filopodia are dynamic cellular structures involved in cell-cell interactions and guidance.
Purpose of the Study:
- To investigate the role of basic fibroblast growth factor (bFGF) in mediating nerve-muscle interactions during NMJ formation.
- To elucidate the signaling pathway involving bFGF and its receptor (FGFR1) in regulating axonal filopodia extension.
Main Methods:
- Utilized cultured Xenopus spinal neurons and muscle cells.
- Employed immunoblotting, labeling, recombinant protein treatment, pharmacological inhibition (SU5402), gene expression manipulation (wild-type and dominant-negative FGFR1), and knockdown techniques.
- Assessed filopodia density, asymmetric extension, and acetylcholine receptor aggregation at innervation sites.
Main Results:
- Muscle-derived bFGF significantly increased neuronal filopodia density via FGFR1 activation.
- Inhibition or suppression of FGFR1 signaling reduced filopodia formation and NMJ assembly.
- bFGF knockdown in muscle impaired axonal filopodia extension and NMJ formation.
- Neurons with suppressed FGFR1 signaling showed reduced ability to induce acetylcholine receptor aggregation.
Conclusions:
- bFGF-FGFR1 signaling in neurons is essential for generating filopodia that facilitate nerve-muscle interaction.
- This signaling pathway plays a critical role in promoting the establishment and specialization of neuromuscular junctions.
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