For SαMNs (ChAT+NeuN+MMP-9−), the levels in ALS mice didn’t change significantly at symptomatic prophase (50~60 days) and symptomatic phase (90~100 days), while the levels of SαMNs decreased remarkably at symptomatic progression (130~140 days) in ALS mice compared with the control mice (P < 0.05). This evidence concerns the gene MMP9 and amyotrophic lateral sclerosis.