Abstract
Cerebral infarction can cause secondary damage to nonischemic brain regions. However, whether this phenomenon will appear in central nervous system regions outside the brain remains unclear. Here we investigated pathological changes in the spinal cord and ventral root after ischemic stroke. All rats exhibited apparent neurological deficits post-MCAO, which improved gradually but could still be detected 12-weeks. Neuronal filaments in the corticospinal tract (CST) and neurons in the ventral horn were significantly declined in the contralateral cervical and lumbar enlargement 1-week post-MCAO. These decreases remained stable until 12-weeks, accompanied by progressively increased glial activation in the ventral horn. Axonal degeneration and structural derangement were evident in the contralateral cervical and lumbar ventral root 1-week post-MCAO; these changes spontaneously attenuated over time, but abnormalities could still be observed 12-weeks. The number of neural fibers in the contralateral CST and neurons in the contralateral ventral horn were positively correlated with neurological scores 12-weeks post-MCAO. Additionally, GFAP+cell density in the contralateral CST and ventral horn was negatively correlated with neurological scores. Our results suggest that cerebral infarction can elicit secondary degeneration in the cervical and lumbar spinal cord, as well as the projecting ventral root, which may hamper functional recovery after stroke.
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Introduction
Focal cerebral infarctions can induce trans-synaptic degeneration in nonischemic, remote brain areas, such as the thalamus, hippocampus and substantia nigra, which have synaptic connections with primary ischemic sites1,Statistical analyses Statistical analyses were performed using SPSS 13.0 for windows (SPSS Inc., Chicago, IL, USA). Data were expressed as means ± standard error of mean (SEM). Statistical analyses were conducted using Students’ t tests for two-group comparisons or one-way analyses of variance (ANOVA) followed by Bonferroni corrections for multiple comparisons. Neurological deficit scores were compared using nonparametric Friedman tests. Spearman correlation analyses were used to determine the association between secondary degeneration and neurological deficit scores. P < 0.05 was considered statistically significant.
Additional Information
How to cite this article: Dang, G. et al. Dynamic secondary degeneration in the spinal cord and ventral root after a focal cerebral infarction among hypertensive rats. Sci. Rep. 6, 22655; doi: 10.1038/srep22655 (2016).
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Acknowledgements
This study was supported by the National Basic Research Program of China (2011CB707804), grants from the Natural Science Foundation of China (81200901, 81371277 and 81571107) and grants from the National Key Clinical Department, National Key Discipline and Guangdong Key Laboratory for diagnosis and treatment of major neurological diseases.
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G.D. and X.C. conducted the experiments and wrote the manuscript. Y.C., Y.Z. and F.O. carried out the collection of data and analyzed the results. J.Z. developed the concept and performed the interpretation of data. All authors reviewed the manuscript.
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Dang, G., Chen, X., Chen, Y. et al. Dynamic secondary degeneration in the spinal cord and ventral root after a focal cerebral infarction among hypertensive rats. Sci Rep 6, 22655 (2016). https://doi.org/10.1038/srep22655
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DOI: https://doi.org/10.1038/srep22655
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