Afferent stimulation-induced plasticity and its functional significance

The ability to learn motor tasks is fundamental to human behaviour. In animals it has been shown that motor learning occurs by activity dependent changes in cortical circuitry. Limited evidence exists that similar mechanisms may be involved in humans. This Australian Research Council (ARC) funded project aims to provide further evidence that similar mechanisms are responsible for motor learning in human subjects.  These studies will provide novel insights into human cortical plasticity that, in turn, may lead to the development of more effective therapeutic interventions for brain-injured patients. This aspect of the project has enormous potential significance given the ever increasing aging population and the associated stroke risks.

The role of afferent input in the development of focal task specific dystonia

This research project funded by the National Health and Medical Research Council (NHMRC) is designed to advance our understanding of the mechanisms responsible for focal, task-specific dystonia. This condition is characterised by inappropriate muscular contractions that can result in pain and inability to perform routine but complex motor tasks such as writing (Writer’s cramp). No effective treatment is available presently. The pathology of this condition is thought to be within the basal ganglia. However, recent evidence has suggested that there may also be abnormalities in the sensory and motor cortical regions. Specific afferent input patterns (for example caused by use of the hands) have been implicated in producing alterations in the organisation of these brain regions, and this may lead to the generation of dystonic symptoms. Using transcranial brain stimulation we are investigating the organisation of the motor cortex and testing the influence of afferent input on cortical organisation. If, as we predict, we are able to demonstrate abnormalities of organisation we will assess the feasibility of employing afferent stimulation to re-establish normal organisation. Hopefully, this may lead to a reduction in the severity of symptoms.