Motoneuron degeneration after facial nerve avulsion is exacerbated in presymptomatic transgenic rats expressing human mutant Cu/Zn superoxide dismutase

• Published in: Journal of neuroscience research Vol. 82; no. 1; pp. 63 - 70
• Main Authors: Ikeda, Ken, Aoki, Masashi, Kawazoe, Yoko, Sakamoto, Tsuyoshi, Hayashi, Yuichi, Ishigaki, Aya, Nagai, Makiko, Kamii, Rieko, Kato, Shinsuke, Itoyama, Yasuto, Watabe, Kazuhiko
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.10.2005
• Subjects: ALS; amyotrophic lateral sclerosis; Animals; Animals, Genetically Modified; axotomy; Axotomy - methods; Cell Count - methods; Cell Survival - physiology; Disease Models, Animal; facial nerve; Facial Nerve Injuries - complications; Facial Nerve Injuries - metabolism; Functional Laterality - physiology; Humans; Immunohistochemistry - methods; Motor Neurons - metabolism; mutant Cu/Zn superoxide dismutase; Nerve Degeneration - etiology; Nerve Degeneration - metabolism; Rats; SOD1; Statistics, Nonparametric; Superoxide Dismutase - genetics; Superoxide Dismutase - metabolism; transgenic rat
• ISSN: 0360-4012; 1097-4547
• DOI: 10.1002/jnr.20621

We investigated motoneuron degeneration after proximal nerve injury in presymptomatic transgenic (tg) rats expressing human mutant Cu/Zn superoxide dismutase (SOD1). The right facial nerves of presymptomatic tg rats expressing human H46R or G93A SOD1 and their non‐tg littermates were avulsed, and facial nuclei were examined at 2 weeks postoperation. Nissl‐stained cell counts revealed that facial motoneuron loss after avulsion was exacerbated in H46R‐ and G93A‐tg rats compared with their non‐tg littermates. The loss of motoneurons in G93A‐tg rats after avulsion was significantly greater than that in H46R‐tg rats. Intense cytoplasmic immunolabeling for SOD1 in injured motoneurons after avulsion was demonstrated in H46R‐ and G93A‐tg rats but not in their littermates. Facial axotomy did not induce significant motoneuron loss nor enhance SOD1 immunoreactivity in these tg rats and non‐tg littermates at 2 weeks postoperation, although both axotomy and avulsion elicited intense immunolabeling for activating transcription factor‐3, phosphorylated c‐Jun, and phosphorylated heat shock protein 27 in injured motoneurons of all these animals. The present data indicate the increased vulnerability of injured motoneurons after avulsion in the presymptomatic mutant SOD1‐tg rats. © 2005 Wiley‐Liss, Inc.