Abstract # 141:

Scheduled for Friday, August 19, 2005 04:35 PM-05:10 PM: Session 12 (Crystal Ballroom) Oral Presentation


T. Preuss
Yerkes National Primate Research Center, Division of Neuroscience, Atlanta, GA 30329, USA
     Neuroscientists know remarkably little about how the human brain differs from that of other species. The development of techniques for assessing tissue-specific gene-expression levels (including microarrays), makes it possible, by comparing humans and chimpanzees, to identify genes and proteins that underwent expression-level changes during human brain evolution. With this knowledge, one can use standard immunocytochemical and in situ hybridization techniques to identify the anatomical loci of molecular changes in the human brain. Several studies comparing human and chimpanzee cortex have recently been published and we are currently undertaking a metanalysis of results, in collaboration with the laboratory of Daniel Geschwind (UCLA). Among the approximately 550 genes identified as differentially expressed in adult human cortex are at least 30 genes with protein products that are likely involved in the regulation of synapse and dendritic spine formation, neurite growth, and long-term potentiation. Most of these are upregulated in humans, including two thrombospondins (THBS2, THBS4). Thrombospondins have recently been identified as key glia-secreted proteins that induce neurons to form synapses. Our results suggest that humans evolved molecular specializations that promote the rapid turnover of synapses in adult cortex. Supported by the James S. McDonnell Foundation and NIH grant AG13854 to the Northwestern University Alzheimer's Disease Center and Neuropathology Core Tissue Bank.