Fig. 7
Astrocytes near MFB spheroids present the autophagy mechanisms needed to process the dopaminergic detritus. MFB astrocytes (a1) showed TH (a2) and LC3 (a3) immunoreactivity. a4 The LC3 and TH levels were highly correlated, and Pearson and Manders coefficients showed TH-LC3 colocalization. b1–b2 and b3–b4 show two examples of MFB astrocytes (cyan arrows; GFAP in cyan and DAPI in blue) near degenerating axons and spheroids of the MFB (green arrow in b1) and showing Lamp1 (yellow arrow in b2) and Lamp2 (yellow arrow in b4) immunoreactivity. DAergic cells (c1) of the substantia nigra with MitoDAT mitochondria (c2) expressed P62 (c3), a protein also found in spheroids (c4–c8). c4 A 3D example of a spheroid showing aggregation of mitochondria inside (c5). c6–c8 Consecutive slices of the aggregated mitochondria of c5 connected by P62 protein (white arrows). Cathepsin was found in the somata (black arrows in d1) and processes (white arrows in d2) of astrocytes of the degenerating MFB. d3–d8 Consecutive slices showing that the cathepsin immunoreactivity was particularly high in the astrocytic processes that penetrated or surrounded the mitochondrial aggregations of spheroids but not within the spheroids (white arrows). e–g Microglial cells (Iba1 in pink and DAPI in blue) located near spheroids or degenerating axons (black arrows) of the MFB neither accumulated TH (green) nor showed CD68 immunoreactivity. h TH-Iba1 cytofluorogram, and the Iba1-TH and Iba1-CD68 Pearson and Manders coefficients (n = 130) showing no statistical colocalization