Randy Bruno earned his B.S. in cognitive science from Carnegie Mellon University and his Ph.D. in neurobiology from the University of Pittsburgh School of Medicine, where he worked with Daniel Simons. He was a postdoctoral fellow at the Max Planck Institute for Medical Research in Germany in the laboratory of Bert Sakmann, and joined the faculty of Columbia University in 2007. He has been a Klingenstein Fellow, a Grossman-Kavli Scholar and a Ludwig Schaefer Research Scholar, and has won the Dr. Harold and Golden Lamport Research Award in the Basic Sciences and the Society for Neuroscience Young Investigator Award.
The cerebral cortex is a key brain structure underlying cognition—all of our higher mental abilities, including sensation, perception, problem solving, decision-making and motor planning. Bruno and his colleagues recently discovered that, rather than being a monolithic structure, the cerebral cortex may contain two entirely different structures working in parallel. Signals from sensory organs are relayed to the cortex via the thalamus. Each axon from the thalamus densely targets the upper half of the cortex, while only sparsely targeting deeper cortical layers. Bruno’s team has shown that, while the axonal branches in the deep layers are relatively sparse, they still account for numerous connections onto neurons of the deep layers. They have further discovered that pharmacologically or optogenetically silencing activity in the upper cortical layers has no detectable impact on the activity of the deep layers. The thalamus appears to be independently driving activity in the upper and deeper halves of the cortex as if they are two separate systems. is conclusion is likely a general principle of the cerebral cortex—ranging from primary sensory areas, to high-level face and object recognition areas, to frontal executive regions—because all neocortical areas and mammalian species exhibit similar thalamocortical wiring.