Effects of pharmacological treatments on hippocampal NCAM1 and ERK2 expression in epileptic rats with cognitive dysfunction

Quercetin attenuates brain apoptosis in mice with chronic unpredictable mild stress-induced depression

BACKGROUND

Depression is a common psychiatric disorder with limited effective treatments. Research suggests that depression involves apoptosis mechanisms. Quercetin (QUE) has been reported to have anti-apoptotic activities. In this study, we aimed to investigate the effects and mechanisms of QUE in chronic unpredictable mild stress (CUMS)-induced depression.

METHODS

After establishing mouse models of CUMS-induced depression, the mice were randomly assigned into four groups: control, CUMS, CUMS+QUE, and CUMS+Fluoxetine (FLX). The body weight of the mice was measured during the study. Then, depression-associated behaviors were evaluated using the sucrose preference test (SPT), novelty suppressed feeding test (NSFT), forced swim test (FST) and tail suspension test (TST). Apoptosis in the hippocampus and prefrontal cortex was determined using flow cytometry. Bcl-2 and Nrf2 protein expressions in the hippocampus and prefrontal cortex were also detected. Furthermore, Western blot was used to measure the protein levels of p-ERK, ERK, p-CREB, CREB, and Nrf2 in brain tissues.

RESULTS

QUE or FLX administration increased the body weight of the CUMS mice. Behavioral tests indicated that CUMS mice developed a state of depression, but QUE or FLX treatment improved their depression-associated behaviors. Meanwhile, QUE or FLX treatment decreased apoptosis in the hippocampus and prefrontal cortex. Furthermore, the decreased Nrf2 protein expression, ERK and CREB phosphorylation in CUMS group were enhanced by QUE or FLX administration.

CONCLUSION

QUE could attenuate brain apoptosis in mice with CUMS-induced depression, and the mechanism may be related to the ERK/Nrf2 pathway, indicating that QUE could be a potential treatment for depression.

An association study in the Taiwan Biobank elicits three novel candidates for cognitive aging in old adults: NCAM1, TTC12 and ZBTB20

The dopamine receptor-related loci have been suggested to be associated with cognitive functions and neurodegenerative diseases. It is unknown whether genetic variants such as single nucleotide polymorphisms (SNPs) in the dopamine receptor-related loci could contribute to cognitive aging independently as well as by virtue of complicated interplays in the elder population. To assess whether SNPs in the dopamine receptor-related loci are associated with cognitive aging in the elder population, we evaluated SNPs in the DRD1, NCAM1-TTC12-ANKK1-DRD2, DRD3-LOC107986115-ZNF80-TIGIT-MIR568-ZBTB20, DRD4, and DRD5-SLC2A9 loci from 25,195 older Taiwanese individuals from the Taiwan Biobank. Mini-Mental State Examination (MMSE) was scrutinized for all participants, where MMSE scores were employed to evaluate cognitive functions. From our analysis, we identified three novel genes for cognitive aging that have not previously been reported: ZBTB20 on chromosome 3 and NCAM1 and TTC12 on chromosome 11. NCAM1 and ZBTB20 are strong candidates for having a role in cognitive aging with mutations in ZBTB20 resulting in intellectual disability, and NCAM1 previously found to be associated with associative memory in humans. Additionally, we found the effects of interplays between physical activity and these three novel genes. Our study suggests that genetic variants in the dopamine receptor-related loci may influence cognitive aging individually and by means of gene-physical activity interactions.

Withania somnifera leaf alleviates cognitive dysfunction by enhancing hippocampal plasticity in high fat diet induced obesity model

Background

Sedentary lifestyle, psychological stress and labor saving devices in this current society often disrupts the energy gain and expenditure balance leading to obesity. High caloric diet is associated with the high prevalence of cognitive dysfunction and neuropsychiatric disorders in addition to cardiovascular and metabolic abnormalities. The present study was aimed to elucidate the potential beneficial effect of dry leaf powder of Withania somnifera (Ashwagandha) in preventing the cognitive decline associated with diet induced obesity.

Methods

Experiments were performed on four groups of young adult female rats: [Low fat diet (LFD) rats fed on regular low fat chow, High fat diet (HFD) rats on feed containing 30% fat by weight, Low fat diet extract (LFDE) rats given regular chow and dry leaf powder of Ashwagandha 1 mg/g of body weight (ASH) and high fat diet extract (HFDE) rats fed on diet containing high fat and dry leaf powder of ASH. All the rats were kept on their respective diet regimen for 12 weeks.

Results

ASH treated rats showed significant improvement in their working memory and locomotor coordination during behavioral studies as compared to HFD rats. At the molecular level, ASH treatment was observed to restore the levels of BDNF and its receptor TRKB as well as the expression of other synaptic regulators, which are highly implicated in synaptic plasticity. Further, ASH triggered the activation of PI3/AKT pathway of cell survival and plasticity by enhancing the levels of phosphorylated Akt-1 and immediate early genes viz. c-Jun and c-fos.

Conclusions

ASH could be a key regulator in maintaining the synaptic plasticity in HFD induced obesity and can serve as a nootropic candidate against obesity induced cognitive impairments.