The Lewy Body


What are Lewy bodies?
Lewy bodies are abnormal aggregations of proteins. They are primarily composed of the protein alpha-synuclein in addition to small amounts of ubiquitin, and alpha B crystallin (Parkinnen et al.,2005, p. 1).

It is not known how or why they are formed, but upon microscopic analyses of brain tissue it has become evident that Lewy bodies form within cells and displace organelles.

What do they have to do with Parkinson's:
Despite the nature in which they are formed in brain cells, Lewy bodies are believed to be more a symptom of Parkinson's disease, rather than an aetiological factor.
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Figure 1. A Lewy body (depicted as beige mass) within cell, displacing nucleus.
As a consequence of this, Lewy bodies have been used as a further test to see if a theorised Parkinson's disease factor is actually causing the disease (Samaranch et al., 2010, p. 1139). Essentially, if a postmortem analysis reveals there to be collections of Lewy bodies within the Substantia nigra it is strongly suggested that the particular pathogenesis factor being tested attributes to the aetiology of the disease.

In the theory of excess manganese, the Lewy body was particularly useful in highlighting there be neurodegeneration in the striatum and not in the Substantia nigra as there was shown to be collections of Lewy bodies localised only in the striatum.

References

Parkkinen, L., Kauppinen, T., Pirttila, T., Autere, J.M. & Alafuzoff, I. 2005, "Alpha-synuclein pathology does not predict extrapyramidal symptoms or dementia", Annals of Neurology, vol. 57, no. 1, pp. 82-91.

Samaranch, L., Lorenzo-Betancor, O., Arbelo, J.M., Ferrer, I., Lorenzo, E., Irigoyen, J., Pastor, M.A., Marrero, C., Isla, C., Herrera-Henriquez, J. & Pastor, P. 2010, "PINK1-linked parkinsonism is associated with Lewy body pathology", Brain : a journal of neurology, vol. 133, no. Pt 4, pp. 1128-1142.

Figure 1:
http://www.elements4health.com/images/stories/lewy-body.jpg