Lewy bodies contain

(A) a-synuclein # Examination of brain in Parkinson's Disease (PD):> Grossly reveals mild frontal atrophy with loss of the normal dark melanin pigment of the midbrain.> Microscopically there is degeneration of the dopaminergic cells with the presence of Lewy bodies (LBs) in the remaining neurons and processes of the substantia nigra pars compacta (SNpc), other brainstem nuclei, and regions such as the medial temporal, limbic, and frontal cortices.> LBs have a high concentration of a-synuclein and are the pathologic hallmark of the disorder.> Mutations in the a-synuclein gene can cause familial PD by promoting the formation of a-synuclein-positive filaments that aggregate into LBs and Lewy neuritis.