Figure 8

Cimetidine treatment leads to higher density of neurons and greater serotonergic innervation after spinal cord injury in mice. A: Single plane confocal images of spinal cord cross-sections 28 days after spinal cord contusion injury stained with anti-NeuN antibody to label neurons. Note the greater sparing of neurons in the Cimetidine-treated animal compared to the vehicle group. B: Quantification of NeuN labeling in the ventral horn is shown. Mice treated with Cimetidine showed increased survival of NeuN+ neurons in the ventral horn of the spinal cord as compared to controls on either side of the lesion center (Two-way RM-ANOVA; group effect F_(1,7) = 20.65, p = 0.0027; with post-hoc Bonferroni multiple comparison test; p*_(-1000µm) = 0.0448, p*_(-500µm) = 0.0496, p*_(+500µm) = 0.0172, p**_(+1000µm) = 0.0024, n = 4-5 mice per group.) C: Increased serotonergic innervation of the ventral horn treated with Cimetidine is observed at 1mm caudal to the lesion center by 5-HT immunohistochemistry. D: Quantification by optical density measurements shows that there is significantly greater 5-HT innervation in Cimetidine treated mice than in vehicle-treated controls. Mann-Whitney unpaired t test, p ≤ 0.0001, n = 9 per group; Scale bar = 200 µm and 100 µm for A and C, respectively.