Professor Linda Richards, Queensland Brain Institute.
The brain must be wired correctly in order to function. Brain wiring forms both pre- and postnatally through a series of highly orchestrated molecular, cellular and activity-dependent events. Axonal connections between the two sides of the nervous system are known as commissural projections. The development of these connections in the cerebral cortex is regulated by a number of different mechanisms. These include the formation of midline tissue called the commissural plate, the guidance of commissural axons by midline glial and neuronal populations, and the expression of specific axonal guidance molecules. There are three commissural projections in the forebrain of placental mammals; the corpus callosum, the hippocampal commissure and the anterior commissure, all of which function to integrate information between the two hemispheres. Recent data from our laboratory indicates that the correct patterning and formation of the commissural plate provides an essential substrate for commissure formation in the telencephalon. As commissural axons arrive at the midline they must navigate through an environment of both attractive and repulsive molecular axon guidance cues. These molecular cues are expressed by midline glial populations and are critical for commissure formation. As such, midline glia are associated with commissural projections throughout the nervous system of all bilaterally symmetrical animals and the molecules they express are highly conserved. A family of transcription factors called the Nuclear Factor One (Nfi) genes regulate the development of these glia and are thus indirectly crucial for commissure formation. After crossing the midline, callosal axons must find their target in the contralateral hemisphere, and both molecular and activity dependent cues are likely involved in their targeting. We are using the mouse somatosensory system to investigate the mechanisms of callosal targeting in the contralateral hemisphere and the role of thalamic and intrinsic cortical activity in this process. Overall, the formation of the corpus callosum provides an excellent model system for understanding how the brain becomes wired up during development.
Professor Richards did her undergraduate degree at Monash University and obtained her BSc (Hons) and a PhD from The University of Melbourne and The Walter and Eliza Hall Institute in the laboratory of Prof. Perry Bartlett. Her thesis was on the determination of neuronal lineage in the developing spinal cord. She then moved to the USA to complete a postdoctoral fellowship at The Salk Institute for Biological Studies where she worked with Professor Dennis O’Leary on cortical development and formation of the lateral cortical projection through the internal capsule. She began her independent laboratory at The University of Maryland Medical School in 1997, in the Department of Anatomy and Neurobiology chaired by Professor Michael Shipley. In 2005 she moved her laboratory to The University of Queensland and was appointed as an Associate Professor in the Queensland Brain Institute and The School of Biomedical Sciences and in 2006, she was appointed as an NHMRC Senior Research Fellow. In 2010, she was promoted to Professor at The University of Queensland and promoted to NHMRC Principal Research Fellow in 2011. In addition to running her laboratory, Professor Richards is passionate about informing the public about science. In 2006 she founded the Australian Brain Bee Challenge, a program that inspires and excites high school students about science.