Figure 6.

scAAV9-STMN1 treatment prevents motor neuron cell body pathology in SMA mice. Cytological analysis of motor neuron cell body in L3–L5 spinal cord from PND18 treatment groups. (A) Representative images of unaffected (left panel), untreated SMA (middle panel) and treated SMA (right panel) lumbar motor neurons immunostained with Nissl stain (neurotrace) to label neuronal cell bodies and ChAT to label specifically motor neurons. ChAT stain revealed an increased number of motor neurons in STMN1-treated SMA compared to untreated SMA mice. Fluorescent microscope images taken at ×40 magnification. (B) Quantification of motor neuron cell bodies showed a significant increase in cell numbers in STMN1-treated SMA mice compared to untreated SMA. However, STMN1-treated motor neuron cell numbers were still significantly lower than unaffected healthy controls. (C) Morphometric analysis showed a significant improvement in motor neuron cell body area (μm²) of STMN1-treated SMA mice compared to untreated SMA mice. (D) Analysis of cell body perimeter also showed significant improvement in SMTN1-treated SMA motor neurons as compared to untreated SMA. However, these improvements were still significantly lower than unaffected control. Data were analyzed by a one-way ANOVA followed by a Tukey post hoc test for multiple comparisons. Data expressed as mean ± SEM. ^****P < 0.0001, ^***P < 0.001, ^**P < 0.01, ^*P < 0.05, n.s. = not significant. n = 3 animals per treatment (n > 400, cells measured per treatment).