PMID- 15661691 OWN - NLM STAT- MEDLINE DCOM- 20050524 LR - 20210528 IS - 0195-6108 (Print) IS - 1936-959X (Electronic) IS - 0195-6108 (Linking) VI - 26 IP - 1 DP - 2005 Jan TI - Apparent diffusion coefficients in spinal cord transplants and surrounding white matter correlate with degree of axonal dieback after injury in rats. PG - 7-18 AB - BACKGROUND AND PURPOSE: Abnormal apparent diffusion coefficient (ADC) values in injured spinal cord white matter and fibroblast transplants have been shown to correspond with qualitative histologic findings of axonal loss or regeneration. We proposed that ADC values would correlate with quantitative axonal tracing in the transected rubrospinal tract (RST). METHODS: Eleven rats received right-sided lateral funiculus lesions at C3-4 (disrupting the RST) and transplantation of fibroblasts that were unmodified or modified to secrete brain-derived neurotrophic factor (BDNF). Behavioral tests measured hindlimb function at 1, 2, 4, 6, 8, 10, and 12 weeks after injury. At 12 weeks after injury, the antegrade axon tracer biotinylated dextran amine was stereotactically injected into the red nucleus to label the injured RST axons. Animals were sacrificed 2 weeks later. Diffusion-weighted MR imaging of the excised, fixed spinal cord specimens was then performed at 9.4 T. RESULTS: In white matter surrounding transplants, ADC values transverse to axons were elevated and ADC values longitudinal to axons were decreased. These ADC values were more abnormal closer to the transplant, and this correlated with decreases in numbers of labeled RST axons. ADC values in BDNF-expressing fibroblast transplants were significantly lower than those in unmodified fibroblast transplants, and these lower values correlated with decreased axonal dieback. Behaviorally, all animals showed partial recovery, but animals with BDNF-expressing fibroblast transplants had slightly improved hindlimb function compared to those with unmodified fibroblast transplants. CONCLUSION: ADC values may be able to evaluate graft function after spinal cord injury by demonstrating the degree of axonal dieback and preservation. FAU - Schwartz, Eric D AU - Schwartz ED AD - Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia 191047, USA. FAU - Chin, Chih-Liang AU - Chin CL FAU - Shumsky, Jed S AU - Shumsky JS FAU - Jawad, Abbas F AU - Jawad AF FAU - Brown, B Kooper AU - Brown BK FAU - Wehrli, Suzanne AU - Wehrli S FAU - Tessler, Alan AU - Tessler A FAU - Murray, Marion AU - Murray M FAU - Hackney, David B AU - Hackney DB LA - eng GR - NS02230/NS/NINDS NIH HHS/United States GR - K08 NS002230/NS/NINDS NIH HHS/United States GR - R01 NS041380/NS/NINDS NIH HHS/United States GR - P50 NS024707/NS/NINDS NIH HHS/United States GR - NS24707/NS/NINDS NIH HHS/United States GR - NS41380/NS/NINDS NIH HHS/United States PT - Journal Article PT - Research Support, U.S. Gov't, Non-P.H.S. PT - Research Support, U.S. Gov't, P.H.S. PL - United States TA - AJNR Am J Neuroradiol JT - AJNR. American journal of neuroradiology JID - 8003708 RN - 0 (Brain-Derived Neurotrophic Factor) SB - IM MH - Animals MH - Axons/*pathology/physiology MH - Brain-Derived Neurotrophic Factor/pharmacology MH - *Diffusion Magnetic Resonance Imaging MH - Female MH - Fibroblasts/transplantation MH - Hindlimb/innervation MH - *Image Processing, Computer-Assisted MH - Nerve Regeneration/*physiology MH - Neural Pathways/anatomy & histology MH - Prognosis MH - Rats MH - Rats, Sprague-Dawley MH - Red Nucleus/*pathology MH - Retrograde Degeneration/*pathology/physiopathology MH - Spinal Cord/pathology/physiopathology/*transplantation MH - Spinal Cord Injuries/*pathology MH - Statistics as Topic PMC - PMC7975021 EDAT- 2005/01/22 09:00 MHDA- 2005/05/25 09:00 PMCR- 2006/01/01 CRDT- 2005/01/22 09:00 PHST- 2005/01/22 09:00 [pubmed] PHST- 2005/05/25 09:00 [medline] PHST- 2005/01/22 09:00 [entrez] PHST- 2006/01/01 00:00 [pmc-release] AID - 26/1/7 [pii] PST - ppublish SO - AJNR Am J Neuroradiol. 2005 Jan;26(1):7-18.