Friday, 22 July 2011

Time-Lapse Imaging Charts The Change Taking Place In Brain Circuitry During Development

Although it annoys me when people refer to autism as a 'disease,' this research in its references to the effect of environmental inputs upon the developing brain, supports everything we do at Snowdrop when we provide programmes of increased environmental stimulation for children who have neuro-developmental disabilities like cerebral palsy and autism.  With thanks to Medical News Today.


Dr. Ed Ruthazer is a mapmaker but, his landscape is the developing brain - specifically the neuronal circuitry, which is the network of connections between nerve cells. His research at The Montreal Neurological Institute and Hospital - The Neuro at McGill University, reveals the brain as a dynamic landscape where connections between nerves are plastic, changing and adapting to the demands of the environment. Dr. Ruthazer is the winner of the inaugural Young Investigator Award from the Canadian Association for Neuroscience, which recognizes outstanding research achievements. His laboratory uses time-lapse imaging to chart the changes that take place in brain circuitry during development in the hope of advancing treatments for injuries to the central nervous system and therapies for developmental disorders such as autism and schizophrenia. These diseases are widely held to result from errors in brain wiring due to a disruption of the complex interactions between genetic and environmental influences during brain development. 

Astoundingly, nearly one out of every 100 Canadians suffers from one of these disorders, which have been estimated to cost the Canadian economy over $10 billion annually in addition to inflicting a devastating impact on patients and their families. Two of Dr. Ruthazer's recent publications in prominent science journals advance our knowledge of how the brain develops, which is vital to developing advanced therapies, treatments and even early intervention. 

Nature versus nurture 

His new study, published in the prestigious journal Neuron, vividly illustrates the effect of environmental inputs on the developing brain. Exposure to just 20 minutes of intensive visual stimulation during development led to enhanced visual acuity and higher sensitivity to finer and smaller visual targets than non-conditioned controls. 

"There is no room for inaccuracy in the mature brain," says Dr. Ruthazer. In the developing brain, there is an initial overproduction of imprecise connections between nerve cells. During development and learning, these connections are pruned, leaving connections that are stronger and more specific. This refinement occurs in response to inputs from the environment. "Our study shows that intense visual stimulation renders nerve cells more receptive to subsequent learning and refinement." 

Importantly, Dr. Ruthazer's group identified the molecular mechanisms underlying the changes in the nervous system. Environmental stimulation activates the production of a protein called Brain Derived Neurotrophic Factor, or BDNF, which plays a major role in the plasticity of neurons and has two forms: proBDNF facilitates the weakening of inaccurate or poorly targeted connections and mature BDNF strengthens appropriate, effective connections. In this case, in response to environmental activity, these processes led to refinement of nerve cell connections involved in the visual system and required for visual acuity. "This indicates that sensory experience during development leads to rapid production of key proteins used at nerve cell connections to confer long-term stability and increased efficacy at appropriate connection points, while simultaneously helping to eliminate inappropriate connections." 


Anyone wanting more information about the Snowdrop programme should email or visit the Snowdrop website.

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