Research projects

Current Projects

Enquiries from students, postdocs and potential collaborators are always welcome.  If you are interested in undertaking a period of research in the laboratory, please feel free to contact Dr James Bourne  to discuss further.

Which visual cortical areas develop and mature first?

Our recent studies have spatiotemporally profiled the development of the visual cortex of a number of mammals using antibodies which are associated with specific stages of development and functionality (neurofilament, calbindin, parvalbumin, cFos).  Presently we are also identifying proteins involved in earlier stages of development and that may be involved in the formation of borders between areas and establishment of inter-areal connectivity.  Some of these include the molecular guidance molecules (eg Eph/ ephrins, cadherins and semaphorins).

When do visual areas of the brain become connected?

Little is known about how the sensory pathways develop, and what happens during the 'critical period', when specific connections are pruned.  Using a variety of tracer techniques, we are currently profiling the development of connectivity of the primate visual cortex with subcortical areas such as the lateral geniculate (LGN) and pulvinar nuclei.  Studies include the use of fluorescently-labelled CTb, as well as the carbocyanine tracers (see figure of embryonic primate LGN below).  The results of this project will help us elucidate the importance of specific pathways during the development of the cerebral cortex.

What happens if areas of the cortex are damaged early in life?

Many studies have revealed that lesions of the sensory cortex suffered early in life have less consequence on perceptual capability than identical lesions suffered later in life.  This highlights the high level of plasticity of the early postnatal brain, and is believed to be due to significant changes in the organisation of the sensory pathways.  We have successfully modelled this condition in the visual cortex, and are using various techniques to profile the specific reorganisation of the visual pathway.  Studies include a marriage of both electrophysiological, MR imaging (see image of lesioned marmoset V1) and anatomical techniques to profile the specific alterations in pathway and areal organisation.  Moreover, by better understanding the ability of the brain to compensate for the change at this stage of development, we may be able to apply the mechanisms to an adult brain to assist with repair following an injury.

Are there homologous / analogous areas of specific visual areas in other mammals?

Although all mammals have a visual cortex, differences in the number, size and function of areas is observed not only between Orders, but also Subspecies within them.  A better understanding of how areas have evolved in the Class Mammalia will provide insight into the processes required to and extract and perceive (and ultimately make sense of) the finer detail and complexities of our visual world.Do other mammals have anatomically and physiologically homologous visuocortical areas to the primates?  The middle temporal (MT) visual area of primates (A) has been postulated to have a homologous area (PMLS) in the carnivores (B, ferret).  We are presently using a variety of immunohistochemcial techniques to make comparative analysis of visual areas between the primate and the carnivores, flying foxes and rodents.

Can biomaterial affect the repair of the CNS following an injury?

It is believed that stem cell therapies are likely to result in regeneration of neurons within the central nervous system after brain injury.  Biomaterials are held to be important for replacing the extracellular matrix within the central nervous system to hold stem cell derived tissue in place following traumatic brain injury.To be effective, these materials should have a nanostructure and gross characteristics similar to that of the extracellular matrix to ensure compatibility between the endogenous and regenerated tissue and minimise the formation of glial scaring.  The materials should also present chemical and physical cues appropriate to the environment into which they are implanted, as well as enhance growth and function of both endogenous and stem cell derived tissue in contact with it.  A collaboration with Dr John Forsythe (Senior Lecturer, Materials Engineering Department, Monash University and Project Leader in the Cooperative Research Centre for Polymers) results in access to a number of novel biomaterials to examine and evaluate, including nano-fibrous electrospun polymers and various hydrogels. This project will involve testing the effects of implantation of various classes of biomaterials on the endogenous tissue structure and function to determine which class of material will likely result in the most effective implant.