Term
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Definition
| Two major parts of the growth cone |
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Term
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Definition
| Filaments within growth cone |
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Term
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Definition
| Integrins, NCAMS, and Cadherins are all _____ |
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Term
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Definition
Cell Adhesion Molecule
- Transmembrane receptor proteins that bind to extracellular
matrix proteins (laminin, fibronectin and glycoproteins)
- Upon binding activate a cascade of events that leads to axon
growth/elongation |
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Term
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Definition
Cell Adhesion Molecule
• form homophilic reactions--same NCAMs in one cell bind to those in other cells
• binding leads to activation of kinases/signaling molecules
• found on growing axons and on surrounding/target cells |
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Term
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Definition
Cell Adhesion Molecule
• calcium dependent--require Ca2+
to form homophilic bond
• binding leads to activation of kinases/signaling molecules
• found on growing axons and on surrounding/target cells |
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Term
| Chemoattractant/REPULSANTS |
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Definition
| Netrin, Slit, and Semorphins are all ____ |
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Term
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Definition
Chemoattractant/Repulsant
• guides commissural axons (axons that cross the midline)
• expressed highly in the floor plate of developing spinal cord
• expressed in midline of more developed nervous system
• Receptor: DCC (bound in membrane of growth cone)
• DCC-____ binding = favorable F-actin polymerization
• Unc5 receptor makes _____ repulsant |
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Term
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Definition
Chemoattractant/Repulsant
• Receptor: Robo leads to favored actin polymerization
• expressed in the midlines
• important for keeping axon from going back across the midline |
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Term
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Definition
Chemoattractant/Repulsant
• _____ proteins are bind to EXM proteins or bind to
nearby axons and prevent growth
• Receptors (lodged in axon membrane):
• plexin and neuropilin
• binding leads to kinases and other signaling molecules |
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Term
| Attractants and trophic activity |
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Definition
These all deal with:
• NGF (nerve growth factor)
• BDNF
• NT3
• NT4/5 |
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Term
| Netrin (Response switching) |
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Definition
| • _____ guides commissural axons to the midline, but once the axons crosses the midline it now repelled by _____ |
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Term
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Definition
Response switching in Netrin:
Must be a switching of receptors from DCC to _____ |
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Term
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Definition
| These act an intermediate points along growth path where growth cones receive signals and then modify their direction |
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Term
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Definition
Example of _____
• Glial Cells (optic chiasm in mammals)
• CDC42+ Glial cells attract axons in both optic nerves and then allow axons to cross and become contralateral projections |
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Term
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Definition
Example of _____
• Floor plate cells (Spinal cord floor plate)
• Netrin’s switching from attractant to repulsant |
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