Fig. 1

SILK-SIMS measurement of ¹³C labeling in a model of induced α-syn overexpression. a Pathogenic conditions were induced in the rat ventral midbrain by unilateral AAV-mediated α-syn overexpression for one month. Subsequently, the animal was subjected to a 48 h pulse with ¹³C-labeled glucose administered in the drinking water. The effects of α-syn overexpression on the kinetics of ¹³C incorporation were determined by comparing the brain hemisphere injected with AAV6-α-syn with the control hemisphere injected with a non-coding AAV6 vector. b Representative example showing how the SEM ultrastructure image was aligned with the isotopic image measured by NanoSIMS. Note that the NanoSIMS image was rotated relative to the SEM image and acquired with a lower lateral resolution (about 15-fold). Additionally, the NanoSIMS image was slightly distorted (stretched or squeezed) relative to the SEM image because of the movement of the sample stage caused by temperature variations during the relatively long NanoSIMS measurement. The alignment of the two images was done by matching the locations of multiple reference points manually defined by the user. In the ‘alignment’ image, points indicated by ‘ + ’ and ‘✕’ were defined in the SEM and NanoSIMS image, respectively. Superimposed reference points are indicated with ❊.