Linda Richards (Professor of Neuroscience and Deputy Director, Queensland Brain Institute at the University of Queensland; Patron and Scientific Advisor of AusDoCC, the Australian family support group for Disorders of the Corpus Callosum).

Prof Linda Richards is a leading developmental neuroscientist who has conducted pioneering work in how the brain is normally wired during development and what mechanisms may be involved when this process is disrupted. Traditional views of brain development regard the process as hardwired with genes predetermining how brain structures mature. With more modern research methods available, there is evidence that brain development is an adaptive and flexible process with the on-going interaction between genes and the environment playing a crucial role.

Researching individuals with disorders of the corpus callosum (DCC) provides a unique insight into the underlying mechanisms that control the plasticity of the brain and in particular, the development of the neuronal connections between the hemispheres. Prof Richards and colleagues have found the brain can rewire itself during development and produce long-range projections between different brain areas. They are trying to understand how different patterns of brain wiring may relate to the cognitive profile of the individual with DCC; for example, some connections may be essential, while others could be compensated for and not as essential as previously thought. Understanding the role of different patterns of brain wiring could help explain why individuals with DCC have widely different symptoms and outcomes.

A fascinating line of enquiry into the formation of the corpus callosum is to study the mechanisms that led to the evolution of this structure. Interestingly, not all mammals have a corpus callosum; it is present in placental mammals but did not evolve in marsupials and egg-laying monotremes. Instead, their hemispheres communicate by using a simpler network of nerve fibres.

Being based in Australia, Prof Richards and her laboratory team* are in a prime position to study early brain formation in marsupials. They have extensively studied a tiny species of marsupial called the fat-tailed dunnart. This mouse-like creature is born at a very early stage of brain development, just when the nervous system is beginning to form. As most of its cortical development occurs while the joey is inside the mother’s pouch, rather than the uterus, scientists have easy access to studying and manipulating this process – simply by opening up the pouch!

This exciting new scientific approach has allowed researchers to gain crucial insights into the early mechanisms of brain formation as well as genetic and environmental influences. For example, the Satb2 gene, which has been found to contribute to the production of neurons that form the corpus callosum, is also present in the fat-tailed dunnart. This gene may instead have a role in forming other connections such as the anterior commissure in marsupials.

Prof Richards and her laboratory team have also used MRI scans to examine the brains of marsupials and monotremes, and have found that nerve fibres that connect the hemispheres are arranged in a specific pattern, very similar to those found in the corpus callosum. This has led to the conclusion that there are specific ways in which the hemispheres prefer to connect in all mammals, and the principles that guide this formation must originate very early on in mammalian evolution. This provides evidence of a very ancient network, from which the corpus callosum evolved, possibly as a means to expand the existing hemispheric connections, rather than being a structure that evolved independently. These new findings may help our understanding of conditions with abnormal brain connectivity, including DCC.

Prof. Richards’ laboratory members are:

  • Dr Rodrigo Suarez
  • Dr Jens Bunt
  • Dr Laura Fenlon
  • Dr Peter Kozulin
  • Dr Ryan Dean
  • Dr Kok-Siong Chen
  • Dr Timothy Edwards
  • Dr Annalisa Paolino
  • Dr Elizabeth Haines
  • Dr Caitin Bridges
  • Ms Ching Moey
  • Mr Jonathan Lim
  • Ms Laura Morcom
  • Mr Tobias Bluett
  • Ms Yunan Yi
  • Ms Donna Simon

If you want to know more about who the Laboratory members are, please follow the following link. https://qbi.uq.edu.au/richardsgroup