Powered by OpenAIRE graph
Found an issue? Give us feedback
image/svg+xml art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos Open Access logo, converted into svg, designed by PLoS. This version with transparent background. http://commons.wikimedia.org/wiki/File:Open_Access_logo_PLoS_white.svg art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos http://www.plos.org/ eScholarship - Unive...arrow_drop_down
image/svg+xml art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos Open Access logo, converted into svg, designed by PLoS. This version with transparent background. http://commons.wikimedia.org/wiki/File:Open_Access_logo_PLoS_white.svg art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos http://www.plos.org/
versions View all 2 versions
addClaim

This Research product is the result of merged Research products in OpenAIRE.

You have already added 0 works in your ORCID record related to the merged Research product.

Size always matters : an investigation of the influence of connection length on the organization of white-matter in typical development and in autism

Authors: Lewis, John D.;

Size always matters : an investigation of the influence of connection length on the organization of white-matter in typical development and in autism

Abstract

Across species, increases in white matter volume outpace increases in gray-matter volume, but increases in gray- matter volume outpace increases in the size of the corpus callosum. This dissertation explores the hypothesis that this hyposcaling of the callosum stems from the impact of the conduction delays and cellular costs of the long- distance connections on normal developmental mechanisms. Neuroanatomy research to date has only indirectly examined this relation, using measures such as brain volume. The research in this dissertation uses diffusion tensor imaging to more directly measure the relation between the length of the interhemispheric connections and the degree of connectivity -- the ratio of between-area connections to total projection neurons in the areas connected. Using 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, across normal young adult males, connection length is significantly negatively correlated with degree of connectivity in the anterior, posterior, and body of the callosum. Using the same methodology, in typically developing boys a significant relation between connection length and degree of connectivity was found only in the posterior of the callosum. The combined results indicate that the relation between connection length and degree of connectivity develops during childhood and adolescence. Children with autism are known to have enlarged brains during the first years of life. This is predicted to lead to decreased long-distance connectivity. To explore this prediction, neural networks which modeled inter- hemispheric interaction were grown at the rate of either typically developing children or children with autism. By 2 years of simulated age, the networks that modeled autistic growth showed a reduced reliance on long-distance connections, performance reductions, and reductions in structural connectivity. Using the same methodology as with the adults and children, the relation between connection length and degree of connectivity in adults with autism was examined. Connection length and degree of connectivity showed the typical negative relation, but with a reduced degree of connectivity in anterior regions -- the locus of development during the period of maximal brain overgrowth, and where axon diameters are smallest

Country
United States
Related Organizations
Keywords

Autism Research, Corpus callosum Research Size, Diffusion tensor imaging, Autism in children Research, UCSD Cognitive science. (Discipline) Dissertations, Academic, Brain Research Size

Aboitiz, F., Scheibel, A. B., Fisher, R. S., & Zaidel, E. (1992). Fiber composition of the human corpus callosum. Brain Research, 598, 143-153. [OpenAIRE]

Courchesne, E., Karns, C. M., Davis, H. R., Ziccardi, R., Carper, R. A., Tigue, Z. D., et al. (2001). Unusual brain growth patterns in early life in patients with autistic disorder: An MRI study. Neurology, 57, 245-254. [OpenAIRE]

  • BIP!
    Impact byBIP!
    citations
    This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    0
    popularity
    This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
    Average
    influence
    This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    Average
    impulse
    This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
    Average
  • citations
    This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    0
    popularity
    This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
    Average
    influence
    This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    Average
    impulse
    This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
    Average
    Powered byBIP!BIP!
Powered by OpenAIRE graph
Found an issue? Give us feedback
citations
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
0
Average
Average
Average
Funded by
Related to Research communities
EBRAINS