To investigate the expression levels of neurexins and neuroligins in the enteric nervous system (ENS) in Hirschsprung Disease (HSCR). Longitudinal muscles with adherent mesenteric plexus were obtained by dissection of the fresh gut wall of mice, guinea pigs, and humans. Double labeling of neurexin I and Hu (a neuron marker), neuroligin 1 and Hu, neurexin I and synaptophysin (a presynaptic marker), and neuroligin 1 and PSD95 (a postsynaptic marker) was performed by immunofluorescence staining. Images were merged to determine the relative localizations of the proteins. Expression levels of neurexin and neuroligin in different segments of the ENS in HSCR were investigated by immunohistochemistry. Neurexin and neuroligin were detected in the mesenteric plexus of mice, guinea pigs, and humans with HSCR. Neurexin was located in the presynapse, whereas neuroligin was located in the postsynapse. Expression levels of neurexin and neuroligin were significant in the ganglionic colonic segment of HSCR, moderate in the transitional segment, and negative in the aganglionic colonic segment. The expressions of neurexin and neuroligin in the transitional segments were significantly down-regulated compared with the levels in the normal segments (P < 0.05). Expression levels of neurexin and neuroligin in ENS are significantly down-regulated in HSCR, which may be involved in the pathogenesis of HSCR.

The goal of this study was to investigate the expression level of neuroligin-2 in different colon tissue segments of children with Hirschsprung's disease (HSCR) and the correlative clinical significance of serum Gamma-Aminobutyric Acid (serum GABA) in HSCR. Neuroligin-2 was assessed by Immunohistochemistry staining method on routine paraffin section from different colon tissue segments of HSCR (ganglionic colonic segment, transitional colonic segment and aganglionic colonic segment). Western-blot analysis and real-time fluorescence quantitative PCR(qRT-PCR) were applied to compare and evaluate the expression levels of neuroligin-2 from three segments of HSCR, and we used Enzyme-linked Immunosorbent Assay (ELISA) method to detect and compare the serum GABA between HSCR and non-HSCR. Immunohistochemistry staining demonstrated that intensive neuroligin-2 staining was detected in the ganglion cells in the ganglionic colonic and transitional colonic segments from the HSCR children; however, neuroligin-2 staining was down-regulated significantly in the aganglionic colonic segments. The expression levels of neuroligin-2 mRNA and protein in the aganglionic colonic segment were decreased compared to the ganglionic colonic segment and transitional colonic segment (P < 0.05). And the level of serum GABA was significantly higher in HSCR than that in non-HSCR. The expression of neuroligin-2 varies from different segments of HSCR. The down-regulation of neuroligin-2 in aganglionic colonic segments may be correlated with the excessive intestine contraction and further result in HSCR. The over-expression of serum GABA may be considered as a new diagnostic method of HSCR.

BackgroundBoth clinical and preclinical studies revealed that regular intake of green tea reduced the prevalence of depressive symptoms, as well as produced antidepressant-like effects in rodents. Evidence proposed that disturbed reward learning has been associated with the development of anhedonia, a core symptom of depression. However, the relationship between green tea and reward learning is poorly investigated. Our goal was to test whether chronic treatment with green tea in healthy subjects affects the process of reward learning and subsequently regulates the depressive symptoms.MethodsSeventy-four healthy subjects participated in a double-blind, randomized placebo-controlled study with oral administration of green tea or placebo for 5weeks. We used the monetary incentive delay task to evaluate the reward learning by measurement of the response to reward trial or no-reward trial. We compared the reaction time of reward responsiveness between green tea and placebo treatment. Furthermore, we selected Montgomery-Asberg depression rating scale (MADRS) and 17-item Hamilton Rating Scale for Depression (HRSD-17) to estimate the depressive symptoms in these two groups.ResultsThe results showed chronic treatment of green tea increased reward learning compared with placebo by decreasing the reaction time in monetary incentive delay task. Moreover, participants treated with green tea showed reduced scores measured in MADRS and HRSD-17 compared with participants treated with placebo.ConclusionsOur findings reveal that chronic green tea increased the reward learning and prevented the depressive symptoms. These results also raised the possibility that supplementary administration of green tea might reverse the development of depression through normalization of the reward function.

Aim. To investigate the abundance of neuroligin-1 and neurexin II in the enteric nervous system (ENS) of rats on different embryonic days and to explore their potential significance. Methods. The full-thickness colon specimens proximal to the ileocecal junction of rats on embryonic days 16, 18, and 20 and of newborns within 24 hours (E16, E18, E20, and Ep0) were studied, respectively. qRT-PCR was applied for detecting the expressions of neuroligin-1 and neurexin II on mRNA, and western blotting was employed for detecting their further expressions on the whole tissue. Finally, the histological appearance of neuroligin-1 and neurexin IIα was elucidated using immunohistochemical staining. Results. qRT-PCR showed that the neuroligin-1 and neurexin II mRNA expressions of groups E16, E18, E20, and Ep0 increased gradually with the growth of embryonic rats (P < 0.05). Western blotting confirmed the increasing tendency. In immunohistochemical staining, proteins neuroligin-1 and neurexin IIα positive cells concentrated mostly in the myenteric nerve plexus of the colon and their expressions depend on the embryonic time. Conclusion. Neuroligin-1 and neurexin II were both expressed in the ENS and have temporal correlation with the development of ENS, during which neuronal intestinal malformations (NIM) may occur due to their disruptions and consequent abnormal ENS development.

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