User:Mcintee/Transneuronal Degeneration

Wikipedia Proposal: Transneuronal Degeneration

Presented by: Alexander Layton, Margaret McIntee, and Kayla Morse

Main Points

General Definition

Transneuronal degeneration is atrophy of certain neurons after interruption of afferent axons or death of other neurons to which they send their efferent output.

Effects

• Cells shrink
• Cytoplasm increases in electron density
• Nucleic acid material is reorganized
• Membrane bound systems swell
• Nucleolus also gets replaced with a large homogenous cluster of electron dense material
• Astrocytes and microglia digest dying neurons that experience transneuronal degeneration through phagocytosis

Causes

• Results from interruption of afferent axons
• Cut off from sending information to postsynaptic cells
  • Cell removal
  • Cell death or damage (like in excitotoxicity)
• Respiratory chain-deficient neurons
  • Have adverse effect on normal adjacent neurons and induce trans-neuronal degeneration
  • This lead to some neuron death

Types

• Orthograde transneuronal degeneration
  • Neuronal degeneration cause by loss of inputs
  • also called trans-synaptic degeneration
• Retrograde transneuronal degenertaion
  • Neuronal degeneration cause by loss of trophic support for the target

Associate Diseases

• Huntington's disease
• Multiple system atrophies
• Alzheimer’s disease

Current and Future Research

• Macaque monkey enucleation of the eye
• Rat olfactory bulb removal

References

1. Transneuronal Degeneration. (2007). Dorland's Medical Dictionary for Health Consumers.
2. Pinching, A.J., and Powell, T.P. (1971). Ultrastructural features of transneuronal cell degeneration in the olfactory system. J. Cell. Sci. 8, 253-287. PMID 4101588
3. Heimer, L., and Kalil, R. (1978). Rapid transneuronal degeneration and death of cortical neurons following removal of the olfactory bulb in adult rats. J. Comp. Neurol. 178, 559-609. PMID 649783
4. Dufour, E., Terzioglu, M., Sterky, F.H., Sorensen, L., Galter, D., Olson, L., Wilbertz, J., and Larsson, N.G. (2008). Age-associated mosaic respiratory chain deficiency causes trans-neuronal degeneration. Hum. Mol. Genet. 17, 1418-1426. PMID 18245781
5. Stefanis, L., and Burke, R.E. (1996). Transneuronal degeneration in substantia nigra pars reticulata following striatal excitotoxic injury in adult rat: time-course, distribution, and morphology of cell death. Neuroscience 74, 997-1008. PMID 8895868
6. MATTHEWS, M.R. (1964). Further Observations on Transneuronal Degeneration in the Lateral Geniculate Nucleus of the Macaque Monkey. J. Anat. 98, 255-263. PMID 14157007
7. Su, J.H., Deng, G., and Cotman, C.W. (1997). Transneuronal degeneration in the spread of Alzheimer's disease pathology: immunohistochemical evidence for the transmission of tau hyperphosphorylation. Neurobiol. Dis. 4, 365-375. PMID 9440125
8. Corwin, J. (July 31, 2007). Trauma and Regeneration. Neuroscience, 3rd edition 527
9. Cowey, A., Alexander, I., and Stoerig, P. (2011). Transneuronal retrograde degeneration of retinal ganglion cells and optic tract in hemianopic monkeys and humans. Brain 134, 2149-2157. PMID 21705429

Division of Workload

We have decided to meet once a week so that we can go over each other's work, discuss individual research findings, and make a cohesive article. The workload will be divided up by subtopic and each person will be assigned one or two subtopics depending on length.