ENS is remodeled in Il10 ^−/− mice with progressive colitis and in human colon with refractory IBD. (A) Body weight in Il10^−/− mice from 4 wk of age until they developed rectal prolapse and in WT littermates (n = 5 per group). (B) Fecal lipocalin-2 in Il10^−/− and WT mice, measured by ELISA (n = 5 per group). (C) Percentage of total viable cells (left) and absolute cell counts (right) of colonic mucosal macrophages in 13-wk-old Il10^−/− and WT mice, quantified by FC (WT, n = 5; Il10^−/−, n = 4). (D) Percentage of total viable cells (left) and absolute cell counts (right) of colonic mucosal neutrophils in 13-wk-old Il10^−/− and WT mice, quantified by FC (WT, n = 5; Il10^−/−, n = 4). (E) Colon length in 13-wk-old Il10^−/− and WT mice (n = 3 per group). (F) GI transit in 13-wk-old Il10^−/− and WT mice (WT, n = 5; Il10^−/−, n = 4). (G) Confocal images of colonic myenteric plexus from 13-wk-old Il10^−/− and WT mice stained with Hu (neuronal somas) and βIII-tubulin (nerve fibers) antibodies. Images are representative of 13-wk-old Il10^−/− and WT mice (n = 3 per group). Scale bars, 100 μm. (H–J) Changes in colonic myenteric ganglia displayed in G of mice described in A showing (H) total counts of Hu⁺ neurons, (I) counts of neuron clusters, and (J) counts of Hu⁺ neurons per cluster, quantified by confocal microscopy. Data are shown as the mean value per mouse per group (left, n = 3 per group) or as distribution of pooled values generated from analysis of 6–10 fields of view per mouse per group (right). (K and L) Changes in nerve fiber architecture of colonic myenteric plexus displayed in G of mice described in A, showing (K) counts of IGFT regions and (L) area of IGFT regions, quantified by confocal microscopy. Data are shown as the mean value per mouse per group (left, n = 3 per group) or as distribution of pooled values generated from analysis of 6–10 fields of view per mouse per group (right). (M) Confocal images of large bowel mucosa in transmural specimens surgically resected from patients with CRC (normal adjacent region—control) and CD (noninflamed and inflamed regions), stained with βIII-tubulin (nerve fibers), HLA-DR (including macrophages), and Hu (neuronal somas) antibodies, and DAPI (nuclei). Images are representative of CRC (n = 3), CD noninflamed (n = 3), and CD inflamed (n = 2) tissue samples. Scale bars, 100 μm. (N) Confocal images of myenteric ganglia from the same tissue cross-sections as in M. Images are representative of CRC (n = 3), CD noninflamed (n = 3), and CD inflamed (n = 2) tissue samples. Scale bars, 50 μm. (O) HLA-DR⁺ cells (top, to depict inflammation), βIII-tubulin⁺ nerve fibers (mid, to depict innervation), and Hu⁺ neuronal soma density in βIII-tubulin⁺ ganglia (bottom) in the experiment described in M and N, quantified by confocal microscopy. Data are shown as distribution of pooled values generated from analysis of 6–14 ROIs per patient tissue sample (top and mid-panels) or as distribution of pooled values indicating all ganglia analyzed per patient tissue sample. N., normal; non-infl., noninflamed. All graphs show the mean ± SEM, n—mouse or patient. Data are representative of two independent experiments with similar results (A–L). Statistical analyses: unpaired Student’s t test (C–O), multiple t test (A and B), and two-way ANOVA for multiple comparisons (A and B), *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, and ****P ≤ 0.0001. # above pooled data in violin plots (right, H–L) indicates empirical P values calculated by the Nested Leave-One-Out Jackknife strategy, where ###P < 0.001.