Task: Question Answering
Input (English): Context: Parkinson's disease (PD) and dementia with Lewy bodies are common disorders of the aging population and characterized by the progressive accumulation of -synuclein (-syn) in the central nervous system. Aggregation of -syn into oligomers with a ring-like appearance has been proposed to play a role in toxicity. However, the molecular mechanisms and the potential sequence of events involved in the formation of pore-like structures are unclear. We utilized computer modeling and cell-based studies to investigate the process of oligomerization of wild-type and A53T mutant -syn in membranes. The studies suggest that -syn penetrates the membrane rapidly, changing its conformation from -helical towards a coiled structure. This penetration facilitates the incorporation of additional -syn monomers in the complex, and the subsequent displacement of phospholipids and the formation of oligomers in the membrane. This process occurred more rapidly, and with a more favorable energy of interaction, for mutant A53T compared with wild-type -syn. After 4 ns of simulation of the protein-membrane model, -syn had penetrated through two-thirds of the membrane. By 9 ns, the penetration of the annular -syn oligomers can result in the formation of pore-like structures that fully perforate the lipid bilayer. Experimental incubation of recombinant -syn in synthetic membranes resulted in the formation of similar pore-like complexes. Moreover, mutant (A53T) -syn had a greater tendency to accumulate in neuronal membrane fractions in cell cultures, resulting in greater neuronal permeability, as demonstrated with the calcein efflux assay. These studies provide a sequential molecular explanation for the process of -syn oligomerization in the membrane, and support the role of formation of pore-like structures in the pathogenesis of the neurodegenerative process in PD. 
 Question: Which disease of the central nervous system is characterized by the presence of Lewy bodies?
Output (English): parkinson's disease (pd)