Keomanivong, C. | bioRxiv Science

bioRxiv2023

Mice expressing A53T / A30P mutant alpha-synuclein in dopamine neurons do not display behavioral deficits

Alpha-synuclein has been implicated in neurodegenerative diseases such as Parkinsons disease and Dementia with Lewy bodies, with A53T and A30P mutations shown to be disease-causing. It has been reported that transgenic mice with tyrosine hydroxylase promotor-driven expression of A53T / A30P mutant alpha-synuclein in dopamine neurons provide a useful preclinical model of these conditions by virtue of developing dopaminergic neuronal cell death and related behavioral deficits. Here, we report a lack of replication of this finding. Despite detecting robust overexpression of A53T / A30P mutant alpha-synuclein in dopamine neurons, we observed neither cell death or related behavioral deficits in these mice. Our results demonstrate that preclinical models of synucleinopathy need careful validation in the field.

animal behavior and cognition↗

bioRxiv2021

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

One hallmark feature of Parkinsons disease (PD) is Lewy body pathology associated with misfolded alpha-synuclein. Previous studies have shown that striatal injection of alpha-synuclein preformed fibrils (PFF) can induce misfolding and aggregation of native alpha-synuclein in a prion-like manner, leading to cell death and motor dysfunction in mouse models. Here, we tested whether alpha-synuclein PFFs injected into the medial prefrontal cortex results in cognitive deficits in mouse models as measured by interval timing, which is reliably disrupted in PD patients and in rodent models. We injected human alpha-synuclein PFF or monomers in the medial prefrontal cortex pre-injected with adeno-associated virus (AAV) overexpressing human alpha-synuclein. Despite notable medial prefrontal cortical synucleinopathy, we did not observe consistent deficits in fixed-interval timing. These results suggest that cortical alpha-synuclein does not reliably disrupt interval timing in rodent models. HighlightsCortical injection of alpha-synuclein preformed fibrils (PFF) induces diffuse synucleinopathy Cortical injection of PFFs does not affect interval timing in mice Medial prefrontal cortical synucleinopathy does not reliably disrupt interval timing

neuroscience↗