Olfactory deficit and gastrointestinal dysfunction precede motor abnormalities in alpha-Synuclein G51D knock-in mice

Area of Science:

• Neuroscience
• Genetics
• Animal Models

Background:

• Parkinson's disease (PD) is a neurodegenerative disorder with complex etiology, often sporadic and late-onset.
• Existing mouse models for PD have limitations in accurately replicating the spatiotemporal expression of alpha-Synuclein (α-Syn).

Purpose of the Study:

• To create a more physiologically accurate mouse model for Parkinson's disease.
• To investigate the early pathological events and progression of PD in a novel knock-in mouse model.

Main Methods:

• Generation of knock-in mice carrying the G51D SNCA mutation, encoding α-Syn.
• Assessment of motor symptoms, α-Syn phosphorylation at Serine 129, and neuropathological markers in different tissues at various ages.
• Evaluation of olfactory function and gut transit in the mouse model.

Main Results:

• The G51D SNCA knock-in mice exhibit motor symptoms starting at 9 months of age.
• Phosphorylated α-Syn was detected in the olfactory bulb and enteric nervous system by 3 months of age.
• Olfactory deficits and impaired gut transit were observed at 6 months, preceding motor impairments.

Conclusions:

• The G51D SNCA mouse model effectively recapitulates the progressive nature of human Parkinson's disease.
• This model provides a valuable tool for studying PD pathogenesis and evaluating potential therapeutic interventions.
• Early-stage pathologies in the olfactory and enteric systems precede motor deficits in this PD mouse model.