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. 2007 Nov 14;2(11):e1187. doi: 10.1371/journal.pone.0001187

Figure 1. Gene expression in the human hippocampus for cocaine abusers and control subjects.

Figure 1

A, Volcano plot illustrating the total number of genes (13,662) meeting the criterion (≥75% present call). For all genes detected on the Affymetrix Human Genome HGU133 A & B Chip Set, each point represents a gene plotted as a function of fold-change (Log (fold change), y-axis) and statistical significance (-Log (p-value), x-axis). Vertical lines represent p values of 0.05 and 0.01, respectively. The upper and lower horizontal lines represent fold changes of +1.3 and −1.3, respectively. Green represents downregulation, while red illustrates upregulation in group comparisons. B, Clustered Image Map (left panel) of the relative change in gene expression between the control and cocaine exposure groups. The color change reflects relative change according to the scale shown; red indicates positive fold change and blue indicates negative fold change. B) Representative genes (left panel): RECK, OPHN1, CTGF, EPHB4 and PCDH8 (from left to right). C, Principal Components Analysis (PCA) reveals separation between groups for the 242 differentially expressed genes. Red represents the cocaine abusers (COC, n = 8) and blue illustrates the control subjects (CTRL, n = 8).