Figure 4.

The presence of neuronal human α-syn in PLP-αSyn primary cortical cultures is not due to an OL-to-neuron transfer of the protein. (A) Representative immunofluorescence imaging of total α-syn (syn1, red) and endogenous murine α-syn (D37A6, green) in primary cortical cultures PLP-αSyn mouse. (B) Representative immunofluorescence imaging of neurons (NeuN, red) and human α-syn (MJFR1, green) in primary cortical cultures from PLP-αSyn mouse (top) or WT mouse supplemented with PLP-αSyn oligodendrocytes (bottom). (C) Close-up representative illustrations of the merged pictures shown in B. (D) Bar graph of the quantifications of the number of neurons (NeuN+ cells) per well. Equal averages of approximately 5000 neurons were obtained, with no significant differences between conditions (Holm-Sidak corrected multiple t-tests), ns: not statistically different. (E) Bar graph of the quantifications of the ratios of human α-syn positive neurons (hu-syn+ NeuN+/NeuN+ cells) per well in the three different culture conditions. After thresholding out the residual unspecific nuclear staining yielded by MJFR1, these cells are detected solely in PLP-αSyn primary cortical cultures (p-Values obtained with Holm-Sidak corrected multiple t-tests). For each condition 9 fields corresponding to 5.13 mm² that is, 15% of the total well surface, of 2 independent wells were analyzed. Results are representative of 3 independent experiments.