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Updated: May 11, 2026
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Morphological and Functional Evaluation of Axons and their Synapses during Axon Death in Drosophila melanogaster
Published on: March 16, 2020
Distinct pathways mediate axon degeneration during apoptosis and axon-specific pruning
Corey L Cusack1, Vijay Swahari, W Hampton Henley
1Neurobiology Curriculum, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
Nature Communications
|May 23, 2013
Summary
Neurons have distinct pathways for cell death (apoptosis) and axon pruning. Caspase-6 protects axons in pruning but not apoptosis, revealing independent regulation for neural plasticity.
Area of Science:
- Neuroscience
- Cell Biology
- Molecular Biology
Background:
- Neurons possess pathways for programmed cell death (apoptosis) and selective axon degeneration (pruning).
- Both processes involve Bax and caspases, suggesting overlapping molecular mechanisms.
Purpose of the Study:
- To investigate the distinct molecular pathways governing apoptosis versus axon degeneration in neurons.
- To elucidate the specific roles of caspases and other proteins in these two processes.
Main Methods:
- Utilized microfluidic chambers to isolate and study axonal responses.
- Investigated the effects of nerve growth factor deprivation.
- Examined the impact of Caspase-6 deficiency and other apoptotic protein manipulations.
Main Results:
- Caspase-6 is activated in axons during pruning but its deficiency only protects axons in axon-specific, not whole-cell, apoptosis.
- Axon-selective degeneration requires Caspase-9 and Caspase-3, but not Apaf-1, differentiating it from apoptosis.
- Proteasome activity and XIAP protect neuronal cell bodies from caspase activation during axon degeneration.
Conclusions:
- Distinct molecular pathways regulate apoptosis and axon degeneration, allowing neurons to prune axons without undergoing cell death.
- Mature neurons can selectively degenerate axons while restricting apoptosis, enabling long-term neural plasticity.
- Understanding these independent pathways is crucial for insights into neurodegeneration and neural repair.
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