Figure 4.

Imaging mass spectrometry of neuropeptides in L-DOPA induced dyskinesia. (a) (I) Unilateral 6-OHDA injection leads to dopamine depletion (as illustrated by TH immunostaining*); (II) L-DOPA therapy results in two distinct groups with low and high-dyskinesia; (III) MALDI IMS and assignment of ROI and spectra extraction. (b,c) Similarly, dynorphin peptides were found significantly increased in the dorso-lateral striatum of high- (HD) compared to low -dyskinetic (LD) animals and lesion controls (LC). (For panels (a)–(c), this research was originally published in Molecular Cellular Proteomics. Hanrieder et al. Mol. Cell Proteomics2011; M111.009308. Copyright the American Society for Biochemistry and Molecular Biology.³²) (d) (I,II) MALDI IMS reveals significant increase of dynorphin peptide (here alpha neoendorphin) in the substantia nigra (SN). (III) Dynorphin peptide intensity correlated positively with dyskinesia severity.⁹⁵