Results were obtained with all 4 mice treated with MOS and SB. Using confocal imaging of fixed, whole mount preparations, no nerve cells or fibers were visible in the granulation tissue at the anastomosis, although intact myenteric plexus was visible in the intact area in a mouse treated with SB and MOS solution for 1 week after surgery (data not shown). Vehicle treated mice underwent in vivo imaging of the anastomotic region at 1 week (n = 5) and 4 weeks (n = 4) after ileum transection and re-anastomosis (Figure 7). One week after surgery, neither nerve bundles nor ganglia were visualized at the anastomosis. In 58-49-1 contrast, 4 weeks after surgery, a small number of neurons were detected in one preparation (Figure 7A ). In the other three mice treated with vehicle for 4 weeks after surgery, no neurons were detected at any depth within the granulation tissue.The average number of neurons observed amongst nine fields within the anastomosis in mice treated with MOS solution was significantly (P,0.05) larger than that in SB plus MOS treated mice (n = 4) or DMSO-treated mice (n = 4) after anastomosis (Figure 8A). New neurons were observed without oral or anal and mesenteric or anti-mesenteric localizations in any of the three groups (Figure 8A). The average density of neurons observed in all fields within the anastomosis in mice treated with MOS solution was 421689 per 864,900 mm2 (n = 5), significantly (P,0.05) higher than SB plus MOS treated mice (113676 per 864,900 mm2; n = 4) or mice treated with vehicle (100634 per 864,900 mm2; n = 4) (Figure 8B). Moreover, the average number of neurons distributed at the anastomosis in MOS treated mice was about 5 cells per 10,000 mm2, compared to 35 cells per 10,000 mm2 (ganglia areas) in the intact small intestine of mice [11]. The distribution of neurons in depth was analyzed at depths of every 20 mm. In all three groups almost all neurons were located within 100 mm of the surface (Figure 9A ). The total number of neurons in MOS-treated mice was about four-fold of that in SB plus MOS and DMSO treated mice (Figure 9D). Correctly identified fluorescent neurons by 2PM are proved to be neurons with an independent technique at the anastomotic site. NF-positive, DLX2-negative, BrdU-positive and GFP-positive cell is identified as a new neuron (Figure 10A ). NF-negative, DLX2-positive, BrdU-positive and GFP-positive cells seem to be neural progenitors. At this anastomotic site, GFAP-positive enteric glial cells are not found (Figure 10E).Figure 9. The distribution of total neurons in MOS (n = 5), SB+MOS (n = 4) and vehicle-treated (n = 4) mice. 1662274 A, B, C. Number of total neurons at depths of every 20 mm. D. Cumulative numbers from all depths. doi:10.1371/journal.pone.0054814.gIn Vivo Imaging of Enteric NeurogenesisFigure 10. Correctly identified fluorescent neurons by 2PM are proved to be neurons at the anastomosis in MOS-treated mice. A. Green Fluorescent Protein (GFP)-positive cells. B. 5-bromo-2’deoxyuridine (BrdU)-positive cells. C. A neural marker, neurofilament (NF)-positive cell. D. A neural stem cell marker, distal less homeobox 2 (DLX2)-positive cells. E. glial fibrillary acidic protein (GFAP)-negative cells. Red Vitamin D2 web arrows indicate NF+/DLX22/BrdU+/GFP+/GFAP- cell: this cell is a new neuron. Green arrows indicate NF2/DLX2+/BrdU+/GFP+/GFAPcells: these cells seem to be neural progenitors. Similar results are obtained in other preparations. doi:10.1371/journal.pone.0054814.gDiscussionThis is the first study in.Results were obtained with all 4 mice treated with MOS and SB. Using confocal imaging of fixed, whole mount preparations, no nerve cells or fibers were visible in the granulation tissue at the anastomosis, although intact myenteric plexus was visible in the intact area in a mouse treated with SB and MOS solution for 1 week after surgery (data not shown). Vehicle treated mice underwent in vivo imaging of the anastomotic region at 1 week (n = 5) and 4 weeks (n = 4) after ileum transection and re-anastomosis (Figure 7). One week after surgery, neither nerve bundles nor ganglia were visualized at the anastomosis. In contrast, 4 weeks after surgery, a small number of neurons were detected in one preparation (Figure 7A ). In the other three mice treated with vehicle for 4 weeks after surgery, no neurons were detected at any depth within the granulation tissue.The average number of neurons observed amongst nine fields within the anastomosis in mice treated with MOS solution was significantly (P,0.05) larger than that in SB plus MOS treated mice (n = 4) or DMSO-treated mice (n = 4) after anastomosis (Figure 8A). New neurons were observed without oral or anal and mesenteric or anti-mesenteric localizations in any of the three groups (Figure 8A). The average density of neurons observed in all fields within the anastomosis in mice treated with MOS solution was 421689 per 864,900 mm2 (n = 5), significantly (P,0.05) higher than SB plus MOS treated mice (113676 per 864,900 mm2; n = 4) or mice treated with vehicle (100634 per 864,900 mm2; n = 4) (Figure 8B). Moreover, the average number of neurons distributed at the anastomosis in MOS treated mice was about 5 cells per 10,000 mm2, compared to 35 cells per 10,000 mm2 (ganglia areas) in the intact small intestine of mice [11]. The distribution of neurons in depth was analyzed at depths of every 20 mm. In all three groups almost all neurons were located within 100 mm of the surface (Figure 9A ). The total number of neurons in MOS-treated mice was about four-fold of that in SB plus MOS and DMSO treated mice (Figure 9D). Correctly identified fluorescent neurons by 2PM are proved to be neurons with an independent technique at the anastomotic site. NF-positive, DLX2-negative, BrdU-positive and GFP-positive cell is identified as a new neuron (Figure 10A ). NF-negative, DLX2-positive, BrdU-positive and GFP-positive cells seem to be neural progenitors. At this anastomotic site, GFAP-positive enteric glial cells are not found (Figure 10E).Figure 9. The distribution of total neurons in MOS (n = 5), SB+MOS (n = 4) and vehicle-treated (n = 4) mice. 1662274 A, B, C. Number of total neurons at depths of every 20 mm. D. Cumulative numbers from all depths. doi:10.1371/journal.pone.0054814.gIn Vivo Imaging of Enteric NeurogenesisFigure 10. Correctly identified fluorescent neurons by 2PM are proved to be neurons at the anastomosis in MOS-treated mice. A. Green Fluorescent Protein (GFP)-positive cells. B. 5-bromo-2’deoxyuridine (BrdU)-positive cells. C. A neural marker, neurofilament (NF)-positive cell. D. A neural stem cell marker, distal less homeobox 2 (DLX2)-positive cells. E. glial fibrillary acidic protein (GFAP)-negative cells. Red arrows indicate NF+/DLX22/BrdU+/GFP+/GFAP- cell: this cell is a new neuron. Green arrows indicate NF2/DLX2+/BrdU+/GFP+/GFAPcells: these cells seem to be neural progenitors. Similar results are obtained in other preparations. doi:10.1371/journal.pone.0054814.gDiscussionThis is the first study in.