The Relation between Connection Length and Degree of Connectivity in Young Adults: A DTI Analysis
Authors: Lewis, John D.; Theilmann, Rebecca J.; Sereno, Martin I.; Townsend, Jeanne
Source: Cerebral Cortex, Volume 19, Number 3, 16 March 2009 , pp. 554-562(9)
Publisher: Oxford University Press
Abstract:Using diffusion tensor imaging and tractography to detail the patterns of interhemispheric connectivity and to determine the length of the connections, and formulae based on histological results to estimate degree of connectivity, we show that connection length is negatively correlated with degree of connectivity in the normal adult brain. The degree of interhemispheric connectivitythe ratio of interhemispheric connections to total corticocortical projection neuronswas estimated for each of 5 subregions of the corpus callosum in 22 normal males between 20 and 45 years of age (mean 31.68; standard deviation 8.75), and the average length of the longest tracts passing through each point of each subregion was calculated. Regression analyses were used to assess the relation between connection length and the degree of connectivity. Connection length was negatively correlated with degree of connectivity in all 5 subregions, and the regression was significant in 4 of the 5, with an average r2 of 0.255. This is contrasted with previous analyses of the relation between brain size and connectivity, and connection length is shown to be a superior predictor. The results support the hypothesis that cortical networks are optimized to reduce conduction delays and cellular costs.
Document Type: Research Article
Publication date: 2009-03-16
- Cerebral Cortex publishes papers on the development, organization, plasticity, and function of the cerebral cortex, including the hippocampus. Studies with clear relevance to the cerebral cortex, such as the thalamocortical relationship or cortico-subcortical interactions, are also included.