Selective inhibition of intestinal 5-HT improves neurobehavioral abnormalities caused by high-fat diet mice
METABOLIC BRAIN DISEASE
Authors: Pan, Qi; Liu, Qiongzhen; Wan, Renling; Kalavagunta, Praveen Kumar; Liu, Li; Lv, Wenting; Qiao, Tong; Shang, Jing; Wu, Huali
Abstract
Recent literature reported the adverse effects of high-fat diet (HFD) on animal's emotional and cognitive function. An HFD-induced obesity/hyperlipidemia is accompanied by hormonal and neurochemical changes that can lead to depression. The important roles of gut-derived serotonin (5-Hydroxytryptamine, 5-HT) during this processing have been increasingly focused. Hence, to determine the potential role of gut-derived serotonin, HFD model was established in C57BL/6 mice. At the 4th week of feeding, a pharmacologic inhibitor of gut-derived 5-HT synthesis LP533401 (12.5mg/kg/day), simvastatin (SIM) (5mg/kg/day) and benzafibrate (BZ) (75mg/kg/day) were administered for two weeks by oral gavage. Then, intraperitoneal glucose tolerance test (IPGTT), open field test (OFT), tail suspension test (TST), forced swim test (FST), sucrose preference test (SPT) were used to evaluate metabolic and neurobehavioral performances. Immunohistochemical staining, real-time quantitative PCR and other methods were to explore possible mechanisms. It was found that HFD feeding and drug treatments had some significant effects on neurobehaviors and brain: (1) All administrations reduced the total cholesterol (TC) and triglyceride (TG) parametric abnormality caused by HFD. LP533401 and SIM could significantly improve the impaired glucose tolerance, while BZ had no significant effect. (2) LP533401, SIM and BZ alleviated depression-like behavior of HFD mice in OFT, TST, FST and SPT. (3) LP533401 and SIM reversed the inhibition of Tryptophan Hydroxylase 2, Tph2 gene expression and the activation of Indoleamine 2,3-dioxy-Genase, IDO expression in HFD-treated brain, whereas BZ did not. (4) LP533401, SIM and BZ restored the inhibitory expression of 5-HT1A receptor in HFD hippocampus. Conclusions: Selective inhibition of intestinal 5-HT can attenuate depressive-like behavior, reduce 5-HT1AR impairment in hippocampus and correct abnormal 5-HT pathway in brain while ameliorating HFD-induced glucose intolerance. Further experiments are warranted to define the adequate strategy of targeting peripheral 5-HT for the treatment of such co-morbidity.
The Association of TPH Genes With Creative Insight Performance
PSYCHOLOGY OF AESTHETICS CREATIVITY AND THE ARTS
Authors: Zhang, Jinghuan; Zhang, Shun
Abstract
Although great progress has been made in understanding the insight phenomenon, the genetic correlates of insight are still largely unknown. The present study systematically explored the associations of serotonin-related tryptophan hydroxylase (TPH) genes with creative insight performance. Sixteen single-nucleotide polymorphisms covering TPH1 and TPH2 were genotyped in 425 unrelated healthy Chinese undergraduates and were further tested for associations with creative insight performance. Gene-based analysis revealed that TPH2 was associated with creative insight performance. In conclusion, the present study provides the first preliminary evidence for the involvement of TPH2 in the insight phenomenon; further studies are warranted to validate these findings.