Cortical alpha-synuclein preformed fibrils do not affect interval timing in mice.

Area of Science:

• Neuroscience
• Molecular Biology
• Cognitive Science

Background:

• Parkinson's disease (PD) is characterized by Lewy body pathology, linked to misfolded alpha-synuclein.
• Alpha-synuclein preformed fibrils (PFFs) can induce prion-like misfolding and aggregation, causing motor deficits in mouse models.
• Interval timing deficits are observed in human PD patients and rodent models.

Purpose of the Study:

• To investigate if alpha-synuclein PFFs injected into the medial prefrontal cortex (mPFC) cause interval timing deficits.
• To determine the role of cortical alpha-synuclein in cognitive functions relevant to PD.

Main Methods:

• Mice received adeno-associated virus (AAV) for human alpha-synuclein overexpression or control.
• Alpha-synuclein PFFs or monomers were injected into the mPFC.
• Mice performance on a fixed-interval timing task was assessed.

Main Results:

• Injected PFFs induced synucleinopathy in the medial prefrontal cortex.
• No consistent deficits in fixed-interval timing were observed despite cortical pathology.
• Alpha-synuclein pathology in the mPFC did not reliably impair interval timing performance.

Conclusions:

• Cortical alpha-synuclein pathology, induced by PFFs, does not appear to reliably disrupt fixed-interval timing.
• These findings suggest that the medial prefrontal cortex's role in interval timing may be resilient to alpha-synuclein aggregation.
• Further research is needed to understand the complex relationship between alpha-synuclein, brain region, and cognitive dysfunction in Parkinson's disease.