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Localized collapsing cues can steer growth cones without inducing their full collapse
1Department of Neuroscience, University of Pennsylvania, School of Medicine, Philadelphia 19104.
Neuron
|February 1, 1995
Summary
Growth cones avoid collapsing factors by turning away from inhibitory cues, demonstrating localized guidance. This mechanism steers neuronal development through targeted inhibition of cell protrusion.
Area of Science:
- Neuroscience
- Developmental Biology
- Cell Biology
Background:
- Collapsing factors are proteins that induce growth cone collapse and paralysis in cultured embryonic neurons.
- Understanding how growth cones respond to localized guidance cues is crucial for neural development.
Purpose of the Study:
- To investigate the behavioral responses of neuronal growth cones to localized collapsing signals.
- To determine if growth cones can be steered by localized inhibitory cues without complete collapse.
Main Methods:
- Exposing temporal retinal ganglion cell growth cones to localized collapsing stimuli from nasal retinal ganglion cell axons.
- Presenting dorsal root ganglion growth cones with beads coated with collapsin-enriched brain extract or heat-inactivated collapsin.
- Observing growth cone turning behavior in response to localized cues, including filopodial contact.
Main Results:
- Growth cones frequently turned away from localized collapsing stimuli without collapsing.
- Turning behavior was mediated by filopodial contact with the inhibitory cue.
- Growth cones did not turn away from control beads with inactivated collapsin.
Conclusions:
- Localized inhibitory guidance cues can steer growth cone navigation.
- This steering mechanism involves localized inhibition of lamellipodial protrusion, rather than complete collapse.
- Findings suggest a novel mechanism for precise pathfinding during neural circuit formation.