Lumbar motoneuron fate in a mouse model of amyotrophic lateral sclerosis.
Onuf's nucleus, a collection of motoneurons within the spinal cord, is often spared in the neurodegenerative disorder amyotrophic lateral sclerosis. To assess whether these cells survive in a rodent model of this disease, motoneurons were counted in the spinal nucleus of the bulbocavernosus (an homologous structure to Onuf's), as well as in two other cell groups at the same level of the spinal cord, the dorsolateral nucleus and the retrodorsolateral nucleus. In mice displaying signs of neurodegeneration, both the dorsolateral and retrodorsolateral nuclei displayed significant motoneuron loss compared to controls; this cell loss was particularly exaggerated in the retrodorsolateral nucleus of animals displaying a rapid disease progression. However, no significant decline in motoneuron number was observed in the spinal nucleus of the bulbocavernosus, and the perineal muscle bulbocavernosus, which is innervated by this nucleus, appeared to be unaffected. This was in stark contrast to the thigh muscles, which displayed significant atrophy. Overall, these data indicate that the spinal nucleus of the bulbocavernosus is spared from degeneration in an animal model of amyotrophic lateral sclerosis, paralleling observations in patients suffering from this disease. Further study of this resistance to motoneuron loss may provide useful insights into the pathophysiology of the degenerative process.
Hamson
Dwayne K
DK
Kinesiology, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
Hu
Jie Hong
JH
Krieger
Charles
C
Watson
Neil V
NV
D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics / Q000473:pathology* / Q000503:physiopathology; D000818:Animals; D016923:Cell Death / Q000235:genetics; D004195:Disease Models, Animal; D008159:Lumbar Vertebrae; D008297:Male; D051379:Mice; D008818:Mice, Neurologic Mutants; D008822:Mice, Transgenic; D009046:Motor Neurons / Q000473:pathology*; D018482:Muscle, Skeletal / Q000294:innervation; D017773:Pelvic Floor / Q000294:innervation; D013116:Spinal Cord / Q000473:pathology* / Q000503:physiopathology; D013848:Thigh / Q000294:innervation / Q000503:physiopathology