Doctoral Dissertation Improvement: The evolution and genetic basis of primate brain cortical gyrification in a pedigreed Papio population

Washington University, Saint Louis MO

Investigators

Abstract

Elevated cognition, related to the dramatic increase in brain volume, is a hallmark of the primates. Cognition is directly related to the number of neurons in the cerebral cortex and the connectivity network underlying information processing in the brain. Increased cortical folding (gyrification) allows for more neurons to be contained within the volume of the braincase and the arrangement of folds and ridges across the cerebral cortex is an indication of the underlying neural network connecting regions. This dissertation project by Elizabeth Atkinson (Washington University), under the supervision of Dr. James Cheverud, uses a pedigreed baboon population to assess the genetic basis and structure of cortical folding in primates. It then further investigates the genomic regions identified in baboons to determine the role of natural selection in altering the DNA sequence of genes across the primate family tree. Questions addressed include: Is the organizational structure of the cerebral cortex modular? Are brain regions that develop together in utero or work together throughout an organism's life also inherited together? How susceptible to developmental noise is the cerebral cortex? What chromosomal regions and genes affect variation in brain function and cortical traits? Is there evidence that genes affecting cortical traits have been selectively altered at an evolutionary scale? Overall, this project addresses critical questions in human and primate brain evolution, including the genetic architecture of brain morphology, differing cognitive strategies across the primate clade, and the evolutionary mechanisms responsible for their formation. In addition to addressing issues of the genetics of brain morphology and cognition in primates, this project also will involve mentoring undergraduates and local high school students from ethnicities and socioeconomic groups typically underrepresented in the sciences, teaching evolutionary concepts at inner-city St. Louis schools, furthering the efforts of a graduate student-run program for science outreach, and disseminating the notable findings from this project to other scientists at meetings and conferences. Participating in this project will further the scientific career and curriculum vitae of an underprivileged St. Louis high school student, mentored closely over the course of the summer of 2013, who otherwise would have few opportunities to engage in scientific research at this early point in their academic development.