[Abstract Title]. - Society for Neuroscience

differences using fractional anisotropy (FA) revealed two kinds of regions. First, we observed
regions in which FA values did not co-vary with reading scores, suggesting structural differences
unrelated to reading, per se. For example, lower FA was noted in deaf as compared to hearing
individuals in the auditory cortices bilaterally, as expected from the lack of auditory inputs to
these regions from birth. Second, there were regions in which FA values did co-vary with
reading skill, indicating a functional-structural link between reading ability and white matter
structure. Among these regions was the left posterior corona radiata. Importantly, past research
shows that the integrity of this region's microstructure is associated with reading skills in hearing
individuals. For example, hearing individuals with reading disability show reduced FA in the left
posterior corona radiata as compared to control subjects, along with greater FA in this region as
reading proficiency increases. In the current study, deaf individuals also showed reduced FA in
this region as compared to hearing controls. Unlike what has been reported with hearing reading
disabled participants, however, reduced FA was associated with better reading skills in the deaf
group in the left posterior corona radiata. Thus, this white matter pathway may be efficient for
sound-based approaches to reading. Yet, in the absence of auditory input, recruiting this structure
may become detrimental to reading proficiency. Pathways that mediate reading proficiency in
the absence of auditory inputs will be further discussed.
Disclosures: E. Hirshorn, None; M. Mani, None; A. Guidon, None; D. Bavelier , None.
Poster
250. Epilepsy: Networks
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 250.1/V13
Topic: C.06.f. Circuits and systems
Support: NS 052302
Epilepsy Foundation
NIH AG21981
Title: Seizures and long-term changes in network excitability in the dentate gyrus of mice after
experimental brain injury
Authors: *R. F. HUNT 1 , S. W. SCHEFF 2 , B. N. SMITH 1 ;
1 Physiol., 2 Anat. & Neurobio., Univ. of Kentucky, Lexington, KY