The Presynaptic Release Apparatus Is Functional in the Absence of Dendritic Contact and Highly Mobile within Isolated Axons
| Autor: | Stefan R. Krueger, Reiko Maki Fitzsimonds, Annette Kolar |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
General Neuroscience
Neuroscience(all) Immunocytochemistry Presynaptic Terminals Endocytic recycling Dendrite Cell Communication Cell Separation Dendrites Biology Hippocampal formation Hippocampus Synaptic vesicle Axons Rats Cell biology Rats Sprague-Dawley medicine.anatomical_structure Postsynaptic potential medicine Animals Axon Neuroscience Cells Cultured |
| Zdroj: | Neuron. 40(5):945-957 |
| ISSN: | 0896-6273 |
| DOI: | 10.1016/s0896-6273(03)00729-3 |
| Popis: | Whether contact of an axon with a dendrite is a necessary inductive signal for the assembly of functional presynaptic machinery is controversial. Combining FM1-43 imaging with retrospective immunocytochemistry, we observe many functional synaptic vesicle (SV) release sites lacking postsynaptic specializations in cultured hippocampal neurons. These "orphan" release sites share the same exocytic machinery and mechanisms of endocytic recycling as mature synaptic sites. Moreover, quantitative analysis of FM1-43 destaining at these orphan release sites reveals similar kinetics with slightly lower release probabilities. Time-lapse imaging of FM1-43 reveals that orphans are generated by complete or partial mobilization of synaptic release sites that retain their functionality in transit. Orphan clusters fuse with existing synaptic release sites or form novel release sites onto dendrites. Mobilization and stabilization of orphan boutons to new sites of dendritic contact may represent a necessary presynaptic counterpart to postsynaptic changes observed during development and plasticity in the CNS. |
| Databáze: | OpenAIRE |
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