Fig. 2: miRNA expression heatmap and GO prediction in the synaptic fraction.

a Normalized values of 351 miRNAs were plotted in an expression heatmap with hierarchical clustering. miRNAs with high expression are shown with green color on the map whereas miRNAs with low expression are shown in red. For the clustering purpose, the Euclidean method was used to measure the distance, and the average linkage algorithm was applied to calculate the average pairwise distance between all pairs of points. Following the average linkage clustering algorithm, the dendrogram was constructed to demonstrate the expression similarities. b Significantly altered miRNAs in the synaptic fraction of dlPFC from MDD subjects. Out of 351 miRNAs, 8 miRNAs were significantly altered in MDD subjects (6 upregulated: miR-215-5p, miR-192-5p, miR-202-5p, miR-19b-3p, miR-423-5p, miR-219a-2-3p; 2 downregulated: miR-511-5p, miR-483-5p). c GO analysis for biological process showing significant enrichment of terms in various categories associated with neuronal morphogenesis, growth and differentiation. d GO-based functional network using cellular component as predictor, demonstrating significant enrichment of gene sets central to synaptic morphology, function and regulation. The prediction analysis was done following an FDR corrected p value cutoff 0.05 to determine the gene set enrichment in biological process and cellular component category separately. In each category the enriched terms were used to create networks where nodes are presented with terms and connected with edges. As shown in the graphs, if two nodes are connected, then they share 20% (default) or more genes. Bigger nodes represent larger gene sets. Thicker edges represent more overlapped genes.