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Updated: Jun 30, 2026
Diffusion Imaging in the Rat Cervical Spinal Cord
Published on: April 7, 2015
Maturational changes in diffusion anisotropy in the rat corpus callosum: comparison with quantitative histological
Junya Jito1, Satoshi Nakasu, Ryuta Ito
1Department of Neurosurgery, Shiga University of Medical Science, Otsu, Shiga, Japan. xjun5@belle.shiga-med.ac.jp
Purpose:
To determine the main histological components that affect fractional anisotropy (FA) in postnatal development of the rat corpus callosum and compare FA values with histological changes evaluated quantitatively.
Materials And Methods:
Diffusion tensor image (DTI) data of the rat (postnatal 1-10 weeks) corpus callosum were obtained with a 7.0 T MR scanner. Histological parameters were quantitatively assessed in toluidine blue-stained semithin sections. Simple and multiple linear regression analyses were performed to investigate relationships between FA values and histological variables.
Results:
The mean FA value (mFA) increased significantly in the early growth stages, whereas the change became smaller after postnatal week 4. Simple regression analysis showed a high correlation between the area of myelin sheath and mFA (r = 0.856; P < 0.01). The area of extracellular space correlated negatively with mFA (r = -0.813; P < 0.01). In a forward stepwise analysis, the area of myelin sheath had the strongest influence on mFA (P < 0.001), followed by the number of unmyelinated axons (P = 0.113). Multiple linear regression analysis revealed that both parameters predicted mFA with a highly significant adjusted correlation coefficient (r(2) adj. = 0.738, P < 0.001).
Conclusion:
During the early development stage in the rat corpus callosum, the strongest contribution to FA value is the area of myelin sheath.
