Term
| basic pathway of nervous system to synapse formation |
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Definition
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Term
| levels of specificity axons go through |
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Definition
- specific side of the body
- specific cell populations
- location within a population
- cell type within a location
- part/area of the cell
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Term
| location within a population |
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Definition
| repeated patterns of connections compared to another cell group (topography) |
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Term
| topography is maintained through ____ |
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Definition
| multiple levels in a system |
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Term
| specific parts of cell axons connect to |
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Definition
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Term
| cells can have ___ effects on axons growing in a nearby tract |
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Definition
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Term
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Definition
| can act as tropic factors |
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Term
| how do axons form tracts? |
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Definition
| fasciculating: adhesion to other axons |
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Term
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Definition
axons leaving tract as they enter their target cell population, they then slow their growth
from reduction in adhesivity among axons, induce by target cells |
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Term
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Definition
| match timing of target cells to receive synapses (not in retinotectal system) |
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Term
| organized growth of axons to target |
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Definition
| axons recognize each other and sort themselves accordingly, but still find target if scrambled |
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Term
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Definition
| chemical recognition between axons and the cells to which they connect |
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Term
| Sperry's chemospecificity hypothesis |
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Definition
- neurons within a population are different from each other
- these differences depend on position
- these differences are acquired early in development
- these are biochemical differences
- complimentary biochemical labels unite selectively
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Term
| axons from the temporal sice of the retinal are repelled by cells in the posterior tectum |
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Definition
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Term
| what is the aversive activity in the tectum? |
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Definition
| anterior-posterior gradient |
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Term
| ephrin (RTK) signaling-chemospecificity (nasal-temporal topography) |
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Definition
| ligands in gradient in tectum, receptor in gradient in retina |
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Term
ephrin subfamilies
recognition specificity |
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Definition
A and B
promiscuous within a subfamily |
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Term
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Definition
GPI linked vs. transmembrane
Rho-GTPase activation vs. bidirectional |
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Term
| why do retinal axons go to tectum at all if there's any repulsion? |
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Definition
| ephrins can promote growth at low concentration and certain positions |
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Term
| forward and reverse EphB/EphrinB signaling |
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Definition
| possible D-V axis of retinotopic map |
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Term
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Definition
| Wnt: ligand, Ryk: repulsion gradient, Frizzle: receptor/attraction (retina) |
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Term
| tectal layer of axon's synapse |
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Definition
| determined by homophilic interactions with several types of adhesion molecules |
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Term
| refining chemospecific map |
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Definition
| activity dependent mechanisms |
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Term
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Definition
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