title: Elevated gene expression levels distinguish human from non-human primate brains.
abstract: Little is known about how the human brain differs from that of our closest relatives. To investigate the genetic basis of human specializations in brain organization and cognition, we compared gene expression profiles for the cerebral cortex of humans, chimpanzees, and rhesus macaques by using several independent techniques. We identified 169 genes that exhibited expression differences between human and chimpanzee cortex, and 91 were ascribed to the human lineage by using macaques as an outgroup. Surprisingly, most differences between the brains of humans and non-human primates involved up-regulation, with approximately 90% of the genes being more highly expressed in humans. By contrast, in the comparison of human and chimpanzee heart and liver, the numbers of up- and down-regulated genes were nearly identical. Our results indicate that the human brain displays a distinctive pattern of gene expression relative to non-human primates, with higher expression levels for many genes belonging to a wide variety of functional classes. The increased expression of these genes could provide the basis for extensive modifications of cerebral physiology and function in humans and suggests that the human brain is characterized by elevated levels of neuronal activity.
authors.affiliation: Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Mario
authors.initials: M
authors.lastname: Cáceres
authors.forename: Joel
authors.initials: J
authors.lastname: Lachuer
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Zapala
authors.forename: John C
authors.initials: JC
authors.lastname: Redmond
authors.forename: Lili
authors.initials: L
authors.lastname: Kudo
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Geschwind
authors.forename: David J
authors.initials: DJ
authors.lastname: Lockhart
authors.forename: Todd M
authors.initials: TM
authors.lastname: Preuss
authors.forename: Carrolee
authors.initials: C
authors.lastname: Barlow
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D015186:Hominidae / Q000235:genetics*; D006801:Humans; D017403:In Situ Hybridization; D008253:Macaca mulatta / Q000235:genetics; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D002679:Pan troglodytes / Q000235:genetics; D011323:Primates / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity
chemical_list: D018076:DNA, Complementary