Lewy body

Photomicrographs of regions of substantia nigra in this Parkinson's patient show Lewy bodies and Lewy neurites in various magnifications. Top panels show a 60-times magnification of the alpha-synuclein intraneuronal inclusions aggregated to form Lewy bodies. The bottom panels are 20x magnification images that show strand-like Lewy neurites and rounded Lewy bodies of various sizes. Neuromelanin-laden cells of the substantia nigra are visible in the background. Stains used: mouse monoclonal alpha-synuclein antibody; counterstained with Mayer's haematoxylin

Lewy bodies

Lewy bodies are abnormal aggregates of protein that develop inside nerve cells in Parkinson's disease (PD), Lewy body dementia, and some other disorders. They are identified under the microscope when histology is performed on the brain.

Lewy bodies appear as spherical masses that displace other cell components. The two morphological types are classical (brain stem) Lewy bodies and cortical Lewy bodies. A classical Lewy body is an eosinophilic cytoplasmic inclusion consisting of a dense core surrounded by a halo of 10-nm-wide radiating fibrils, the primary structural component of which is alpha-synuclein. Cortical Lewy bodies are also composed of alpha-synuclein fibrils, but are less defined and lack halos. In histopathology, Cortical Lewy bodies are a distinguishing feature for dementia with Lewy bodies (DLB), but may occasionally be seen in ballooned neurons characteristic of Pick's disease and corticobasal degeneration, as well as in patients with other tauopathies. They are also seen in cases of multiple system atrophy, particularly the Parkinsonian variant.

History

Lewy bodies were discovered by Frederic Lewy in 1912.

Cell biology

Photomicrograph of the dorsal motor nucleus of the vagus nerve (DmX) in a transverse section along the upper medulla shown to be affected by the abnormally deposited alpha synuclein as part of intraneuronal Lewy bodies found (extreme right): DmX is one of the earliest sites affected by synuclein deposition in Parkinson's disease.

A Lewy body is composed of the protein alpha-synuclein associated with other proteins, such as ubiquitin, neurofilament protein, and alpha B crystallin. Tau proteins may also be present, and Lewy bodies may occasionally be surrounded by neurofibrillary tangles. Lewy bodies and NFTs can occasionally exist in the same neuron, particularly in the amygdala.

Lewy bodies are believed to represent an aggresome response in the cell.

Lewy neurites

Lewy neurites are abnormal neurites in diseased neurons, containing granular material and abnormal α-synuclein filaments similar to those found in Lewy bodies. Like Lewy bodies, lewy neurites are a feature of α-synucleinopathies such as dementia with Lewy bodies, Parkinson's disease, and multiple system atrophy. They are also found in the CA2-3 region of the hippocampus in Alzheimer's disease.

Cultural reference

Celebrities

Notable people who suffered from Lewy body dementia include:

• Actor Robin Williams
• Actress Estelle Getty
• Music industry icon Casey Kasem
• Athlete Stan Mikita
• Artist Don Featherstone, creator of the iconic lawn flamingo.

In fiction

• In the premiere episode of Boss, Dr. Ella Harris tells Chicago Mayor Tom Kane he has Lewy bodies, and his progressing symptoms are shown in each episode.

See also

• Neurite
• Proteopathy
• Synucleinopathies

External links

• Lewy Body Dementia Association