Mechanisms of secondary degeneration after partial optic nerve transection
Hong-Ying Li1, Yi-Wen Ruan2, Chao-Ran Ren2
1Department of Ophthalmology, the University of Hong Kong, Hong Kong Special Administrative Region, China ; State Key Laboratory of Brain and Cognitive Science, the University of Hong Kong, Hong Kong Special Administrative Region, China.
Abstract:
Secondary degeneration occurs commonly in the central nervous system after traumatic injuries and following acute and chronic diseases, including glaucoma. A constellation of mechanisms have been shown to be associated with secondary degeneration including apoptosis, necrosis, autophagy, oxidative stress, excitotoxicity, derangements in ionic homeostasis and calcium influx. Glial cells, such as microglia, astrocytes and oligodendrocytes, have also been demonstrated to take part in the process of secondary injury. Partial optic nerve transection is a useful model which was established about 13 years ago. The merit of this model compared with other optic nerve injury models used for glaucoma study, including complete optic nerve transection model and optic nerve crush model, is the possibility to separate primary degeneration from secondary degeneration in location. Therefore, it provides a good tool for the study of secondary degeneration. This review will focus on the research progress of the mechanisms of secondary degeneration using partial optic nerve transection model.
Insights
Secondary degeneration in the central nervous system, including glaucoma, involves multiple mechanisms and glial cells. The partial optic nerve transection model effectively separates primary from secondary degeneration, aiding research.
Area of Science:
- Neuroscience
- Ophthalmology
- Cell Biology
Background:
- Secondary degeneration is common in the central nervous system after injury and disease, such as glaucoma.
- Mechanisms include apoptosis, necrosis, autophagy, oxidative stress, excitotoxicity, and ionic imbalances.
- Glial cells (microglia, astrocytes, oligodendrocytes) contribute to secondary injury.
Purpose of the Study:
- To review research progress on secondary degeneration mechanisms.
- To highlight the utility of the partial optic nerve transection model.
Main Methods:
- Focuses on a review of existing research.
- Utilizes the partial optic nerve transection model in animal studies.
- Compares different optic nerve injury models.
Main Results:
- The partial optic nerve transection model allows spatial separation of primary and secondary degeneration.
- This model is advantageous over complete transection or crush models for studying secondary degeneration.
- Identifies key cellular and molecular mechanisms involved.
Conclusions:
- The partial optic nerve transection model is a valuable tool for investigating secondary degeneration.
- Understanding these mechanisms is crucial for developing treatments for conditions like glaucoma.
- Further research using this model can elucidate therapeutic targets.
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