Characterization of spinal motoneuron degeneration following different types of peripheral nerve injury in neonatal and adult mice

作者：Linxi Li, Lucien J. Houenou, Wutian Wu, Ming Lei, David Prevette, Ronald W. Oppenheim · 发表于：The Journal of Comparative Neurology · 年份：1998 · DOI：10.1002/(sici)1096-9861(19980629)396:2<158::aid-cne2>3.0.co;2-# · 被引用次数：110 · 研究领域：Nerve injury and regeneration、Amyotrophic Lateral Sclerosis Research、Neurogenetic and Muscular Disorders Research

Experimental lesions have been used widely to induce motoneuron (MN) degeneration as a model to test the ability of different trophic molecules to prevent lesion-induced alterations. However, the morphological mechanisms of spinal MN death following different types of lesions is not clear at the present time. In this study, we have characterized the morphological characteristics of MN cell death by examining DNA fragmentation and the ultrastructural and light microscopic morphological features of MNs following different types of spinal nerve injury (i.e., axotomy and avulsion) in the developing and adult mouse. In neonatal mice, axotomy induced cell death as well as the atrophy of MNs that survived the injury. DNA fragmentation could be detected by using the terminal deoxynucleotidyl transferase (TUNEL) method during the cell death process following neonatal axotomy, whereas TUNEL labeling was not observed following either neonatal or adult avulsion. However, with the exception of TUNEL labeling, the morphological characteristics of MN death following neonatal axotomy and avulsion were similar, and both resembled most closely the form of programmed cell death termed cytoplasmic or type 3B, which exhibits similarities as well as differences with currently accepted definitions of apoptosis. By contrast, adult avulsion resulted in a type of degeneration that resembled necrosis more closely. However, even there, the morphology was mixed, showing characteristics of both apoptosis ...