It is well known that mutations in genes encoding the Ret receptor tyrosine kinase and endothelin receptor type B are involved in HSCR pathogenesis. We found MOS increased mRNA of c-Ret receptor tyrosine kinase in a rat model and that a 5-HT4 receptor antagonist completely blocked this effect. Therefore, it seems likely that the target molecule of MOS is the Ret receptor tyrosine kinase. Enteric neurogenesis must be strictly controlled, because hyperplasia of enteric neurons due to hypersensitivity for glial cell-derived neurotrophic factor -Ret signaling reversely results in HSCR. Nevertheless, treatment with 5-HT4 receptor agonists such as MOS could be a promising tool to treat HSCR and related disorders. In conclusion, in vivo imaging by 2PM allowed for highresolution deep imaging of the intestines in vivo. Thick granulation tissue at the site of anastomosis, including newly formed ganglionlike structures and nerve fibers, could be studied in the intact murine small intestine, whereas this would have been impossible with traditional fluorescence or confocal microscopy. The results presented here confirmed that oral administration of MOS promotes the generation of enteric neurons by activation of enteric AbMole Taltirelin neural 5-HT4-receptors in the murine small intestine. The present technology would be promising for in vivo imaging of enteric neurons distributed throughout the entire gastrointestinal tract as a means of evaluating enteric neural function and dysfunction in the normal gut and in, for example, diabetic and parkinsonism mouse models. The recent publications suggest that mouse enteric glia can be neuronal precursors and thus form neurons in vitro and in vivo under specific circumstances. Therefore, we have investigated glia and/or their relation to the newly formed “neurons”. However, we did not found any enteric glial cells at the anastomotic site. It seems unlikely that enteric glial cells contribute to neurogenesis at least at the anastomotic site. White matter lesions are clinically relevant since they are associated with a variety of neurological disorders, e. g. strokes, cognitive decline, depression, or epilepsy. WML are frequently documented in brain MRI in elderly subjects. The most prominent risk factors are age and essential hypertension, followed by the remaining classical cardiovascular risk factors. WML may also be detected in younger adults without typical risk factors and are occasionally associated with inflammatory, and, in particular, demyelinating diseases. However, despite extensive diagnostic efforts, the underlying etiology often remains elusive in these patients. Without enzyme replacement therapy, life span in FD patients is dramatically shortened, generally due to heart failure, renal dysfunction and cerebrovascular disease. Ischemic strokes and WML are characteristic neurological complications of FD. Although mono-organic manifestations have been described, a disease manifestation that is limited to WML has not yet been reported. The first identified missense mutation leading to a so-called pseudo-deficient allele was GLA D313Y, which results in decreased enzyme activity in plasma, but nearly normal activity in leukocytes. Although controversially discussed, the D313Y mutation is considered as non-pathogenic by most authors and, thus, D313Y carriers are not treated with ERT. In the current work, we identified an index patient with significant WML carrying D313Y.