Growth cone-like waves transport actin and promote axonogenesis and neurite branching
| Autor: | Frank Bradke, Alisa E. Shaw, James R. Bamburg, Kevin C. Flynn, Chi W. Pak |
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| Rok vydání: | 2009 |
| Předmět: |
Neurite
Growth Cones Hippocampal formation Biology Axonal Transport Hippocampus Axonogenesis Article Mice Cellular and Molecular Neuroscience Organ Culture Techniques Developmental Neuroscience Cell Movement Image Processing Computer-Assisted Neurites medicine Animals Axon Growth cone Cells Cultured Neurons Microscopy Confocal Dentate gyrus Gene Transfer Techniques Immunohistochemistry Actins Axons Rats Cell biology medicine.anatomical_structure Axoplasmic transport Filopodia |
| Zdroj: | Developmental Neurobiology. 69:761-779 |
| ISSN: | 1932-846X 1932-8451 |
| Popis: | Axonogenesis involves a shift from uniform delivery of materials to all neurites to preferential delivery to the putative axon, supporting its more rapid extension. Waves, growth cone-like structures that propagate down the length of neurites, were shown previously to correlate with neurite growth in dissociated cultured hippocampal neurons. Waves are similar to growth cones in their structure, composition and dynamics. Here, we report that waves form in all undifferentiated neurites, but occur more frequently in the future axon during initial neuronal polarization. Moreover, wave frequency and their impact on neurite growth are altered in neurons treated with stimuli that enhance axonogenesis. Coincident with wave arrival, growth cones enlarge and undergo a marked increase in dynamics. Through their engorgement of filopodia along the neurite shaft, waves can induce de novo neurite branching. Actin in waves maintains much of its cohesiveness during transport whereas actin in non-wave regions of the neurite rapidly diffuses as measured by live cell imaging of photoactivated GFP-actin and photoconversion of Dendra-actin. Thus, waves represent an alternative axonal transport mechanism for actin. Waves also occur in neurons in organotypic hippocampal slices where they propagate along neurites in the dentate gyrus and the CA regions and induce branching. Taken together, our results indicate that waves are physiologically relevant and contribute to axon growth and branching via the transport of actin and by increasing growth cone dynamics. |
| Databáze: | OpenAIRE |
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