Active Genes Discovered in the Developing Mammal Brain (3 of 3) (image) Penn State Share Print E-Mail Caption The scientists detected the expression of 1,370 genes in brains on embryonic day 18 (E18), and the expression of 1,373 genes in the brains at post-natal day seven (P7). Among the genes detected on embryonic day 18, the scientists detected the expression of 396 genes that were not detected on post-natal day seven. Among the genes detected on post-natal day seven, the expression of 399 genes was not detect on embryonic day 18. This differential activity suggests that different processes are active in the brain at these two stages of brain development. Credit Christina Manbeck, Penn State Usage Restrictions The credit information must be published along with the picture. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.