Distinguished Yale Neurobiologist Delivers James Arthur Lecture at the American Museum of Natural History
Pasko Rakic, the Dorys McConnell Duberg Professor and chair of the Department of Neurobiology at Yale School of Medicine, recently gave the 71st James Arthur Lecture on the “Evolution of Neocortex: Lessons from Embryoarcheology” at the American Museum of Natural History.
It was noted in introducing Rakic that the objective of his research is to better understand the molecular mechanisms that govern cellular events during development of the mammalian brain, including neurogenesis, neuronal migration and synaptogenesis. He and his colleagues also have made significant contributions to a greater understanding of the evolutionary growth of the cerebral cortex and the pathogenesis of a host of genetic and acquired abnormalities of this structure in humans.
Rakic is a member of the National Academy of Sciences, the American Academy of Sciences and the Institute of Medicine. He also is past president of the Society for Neuroscience.
In his lecture, Rakic proposed that insight into the evolution of the cerebral cortex, the crowning achievement of evolution, could be obtained by the study of molecular and cellular events during the embryogenesis of living species. Since only those changes in the brain that are inherited make an impact on its evolution, the secrets of our phylogenetic history are inscribed in the sequences of differential gene expression and cellular events.
Rakic emphasized that advances in understanding corticogenesis in the embryo provide insight into how spontaneous gene mutations that regulate the early stages of corticogenesis may have determined the species-specific size and basic organization of the cerebral cortex.
His laboratory is currently applying knowledge derived from genes identified in invertebrates, isogenic mice and the Human Genome Project to compelling issues in primate brain development. The regulatory genes that determine the number of progenitor founder cells by controlling the timing and mode of cell divisions as well as the magnitude of programmed cell death are being tested in transgenic murine model systems of cortical expansion and in living brain slice preparations. From such studies, Rakic said, we can learn how one set of genes interacts with another to create the conditions for orderly cortical expansion that may have happened during evolution.