Pathway analysis of the significantly lesion- vs. sham-regulated genes in aged and young animals.

<p>Pathway analysis at different time points was done using the Ingenuity curated database of gene interactions of over 23,900 human, rat, and mouse genes. In this analysis, genes were tested for significant association in specific cell functional or signaling pathways versus random chance association in a total of gene interactions using right-tailed Fisher's exact test (Ingenuity Systems). Significance was assessed by testing the number of genes that were regulated by sprouting neurons in a specific pathway versus total number of genes in this database for that pathway (blue columns). The red line in the left graph indicates the threshold for a significant association, the −log (0.05). For example, if the pathway has a <i>P-score</i> of 10, the odds of this pathway being generated at random are less than 1 out of 10¹⁰.