Grant: Discovery Grants Program - Individual

One of the major shifts in thinking about brain-behaviour relations in the past 25 years is the recognition that the brain is constantly changing. This variability in organization reflects the brain's capacity to alter its structure and function in reaction to environmental diversity, thus reflecting a capacity that is often referred to as brain plasticity. Although this term is now commonly used in psychology and neuroscience, it is not easily defined and is used to refer to changes at many levels in the nervous system ranging from molecular events, such as changes in gene expression, to behavior. The relationship between molecular or cellular changes and behavior is by no means clear and is plagued by the problems inherent in inferring causation from correlation. ) I have proposed to do a broad range of experiments that have the common goal of determining the ""rules"" of cortical plasticity for diverse cortical regions. These proposed studies follow up on some of my most intriguing findings over the past grant period, especially those related to age, sex, and cerebral location. The key point is that although I tended to think of experience as having a singular effect on the brain, it has become clear that the effects of experience vary with a variety of factors, some of which are unexpected. Given the complexity of cortical anatomical and neurochemical organization, as well as the differences in developmental sequences in different regions, the heterogeneity of plastic processes in the cerebrum should not be surprising. The goal, therefore, is to determine the rules that might govern this diversity. Further studies will search for molecular mechanisms that may underlie our morphological and behavioural observations. These studies are relevant both to our understanding of the relationship between brain construction and behavioral change as well as to the design of more effective therapies for the treatment of people with brain injury.