Figure 2
Second order linear analysis reveals specific patterns of correlations in gene expression levels in midbrain DA and nDA neurons. (a) Heatmap representing the significant correlations in expression levels for 33 genes in DA neurons (upper right triangle) and nDA neurons (lower left triangle) (Pearson correlation coefficient). Correlations were processed on non-zero values of expression, and only correlations with a p value < 0.05 and n > 5 are represented. Please note the difference in patterns of correlations between DA and nDA neurons.(b) Scatter plots presenting examples of significant correlations in gene expression levels. Green and dark red dots correspond to DA and nDA neurons, respectively. r, p, and n values are displayed for each correlation test. Plain and dotted lines indicate significant and non-significant Pearson correlations, respectively. Protein names are given in parentheses. (c) Scaffold representations of the 20 most significant correlations in expression levels in DA (left) and nDA (right) neurons (r values > 0.6 or < −0.6, see color coding in the top middle box). Genes were ordered based on the known function of the corresponding proteins (see table at the bottom for the color-coding of functions). Genes involved in the depicted correlations are highlighted (dark font). Please note the strong connectivity between DA metabolism/signaling and ion channel genes in DA neurons.
