A light-inducible protein clustering system for in vivo analysis of α-synuclein aggregation in Parkinson disease
Fig 5
LIPA-α-syn aggregation disrupts nigrostriatal neuronal transmission.
(A) Schematic representation of the in vivo experimental paradigm of light-induced α-syn aggregation in the SNc and Ca2+ imaging in the striatum. (B) Confocal microscopy image reconstitution of a sagittal brain slice illustrating the expression of LIPA-α-syn in the SNc and the Ca2+ indicator GCaMP6s in the striatum (n = 5 mice)(scale bar = 500μm). (C) Representative time-lapse live imaging illustration of mini-endoscopic Ca2+ in the striatum. Arrowheads indicate striatal neurons showing Ca2+ activity (scale bar = 20μm). (D) Confocal images illustrating the presence of LIPA-α-syn expression in the majority of dopaminergic TH-positive neurons (n = 5 mice) (scale bar = 20 μm). (E) High magnification of confocal images showing that pathological pS129-positive LIPA-α-syn aggregates persisted in dopaminergic neurons 10 days post-optogenetic stimulation (n = 4–6 mice) (scale bar = 10 μm). (F) Temporal trajectories of synchronicity, frequency, and amplitude of Ca2+ transients before, during, and after light-induced α-syn aggregation (n = 4–5 mice). (G) Temporal trajectories of synchronicity, frequency, and amplitude of Ca2+ transients in the absence of light-induced LIPA-α-syn aggregation (n = 3 mice). (H) Temporal trajectories of synchronicity, frequency, and amplitude of Ca2+ transients before, during, and after light-induction in LIPA-α-synΔNAC (n = 4–5 mice). The data are presented as the means ± SEM. * p ≤ 0.05 and ** p ≤ 0.01. The underlying data for (F) to (H) can be found in S1 Data. α-syn, α-synuclein; LIPA, light-inducible protein aggregation; pS129, phosphorylated α-syn at S129; SNc, substantia nigra pars compacta.