Question

What role does alpha-synuclein play in the development of LBD and PD?

1) It has no role in the development of LBD and PD
2) It is responsible for the development of LBD but not PD
3) It is responsible for the development of PD but not LBD
4) It plays a role in the development of both LBD and PD

Answer 1

Alpha-synuclein plays a crucial role in the development of both LBD and PD by contributing to the formation of toxic protein aggregates, known as Lewi bodies, which lead to the loss of dopaminergic neurons and are associated with the severity of these diseases.

Step-by-step explanation:

The role of alpha-synuclein in the development of Lewy Body Dementia (LBD) and Parkinson's Disease (PD) is significant. Both diseases are characterized by the presence of Lewi bodies, which are cytoplasmic protein aggregates mainly composed of alpha-synuclein and other proteins.

These aggregates are toxic to the cells in the substantia nigra nucleus in the midbrain. In PD, the loss of dopaminergic neurons in the substantia nigra pars compacta (SNC), projecting to the corpus striatum, is a pathological hallmark, which is also associated with mitochondrial dysfunction, oxidative stress, and glutamate excitotoxicity. The presence of Lewi bodies and the prevalence of these aggregates correlate with the severity of PD. Therefore, alpha-synuclein plays a pivotal role in the development of both LBD and PD (Option 4).