Impact of α-synuclein spreading on the nigrostriatal dopaminergic pathway depends on the onset of the pathology.
Brain Pathol
; 32(2): e13036, 2022 03.
Article
em En
| MEDLINE
| ID: mdl-34806235
ABSTRACT
Misfolded α-synuclein spreads along anatomically connected areas through the brain, prompting progressive neurodegeneration of the nigrostriatal pathway in Parkinson's disease. To investigate the impact of early stage seeding and spreading of misfolded α-synuclein along with the nigrostriatal pathway, we studied the pathophysiologic effect induced by a single acute α-synuclein preformed fibrils (PFFs) inoculation into the midbrain. Further, to model the progressive vulnerability that characterizes the dopamine (DA) neuron life span, we used two cohorts of mice with different ages 2-month-old (young) and 5-month-old (adult) mice. Two months after α-synuclein PFFs injection, we found that striatal DA release decreased exclusively in adult mice. Adult DA neurons showed an increased level of pathology spreading along with the nigrostriatal pathway accompanied with a lower volume of α-synuclein deposition in the midbrain, impaired neurotransmission, rigid DA terminal composition, and less microglial reactivity compared with young neurons. Notably, preserved DA release and increased microglial coverage in the PFFs-seeded hemisphere coexist with decreased large-sized terminal density in young DA neurons. This suggests the presence of a targeted pruning mechanism that limits the detrimental effect of α-synuclein early spreading. This study suggests that the impact of the pathophysiology caused by misfolded α-synuclein spreading along the nigrostriatal pathway depends on the age of the DA network, reducing striatal DA release specifically in adult mice.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doença de Parkinson
/
Alfa-Sinucleína
Limite:
Animals
Idioma:
En
Revista:
Brain Pathol
Assunto da revista:
CEREBRO
/
PATOLOGIA
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Alemanha