Buckwheat Flour and Its Starch Prevent Age-Related Cognitive Decline by Increasing Hippocampal BDNF Production in Senescence-Accelerated Mouse Prone 8 Mice.

Buckwheat is an important pseudo-cereal crop worldwide. This study investigated whether long-term administration of buckwheat can suppress age-related cognitive decline in senescence-accelerated mouse prone 8 (SAMP8) mice. For 26 weeks, 18-week-old male SAMP8 mice were fed a standard diet containing 5% (w/w) buckwheat, Tartary buckwheat, wheat, or rice flour. In the Barnes maze and passive avoidance tests, mice fed buckwheat whole flour (BWF) showed improved cognitive performance compared to those fed a control diet, while no improvement was noticed in case of the other diets. Analysis of the gut microbiota showed that BWF and buckwheat outer flour administration increased the abundance of Lactococcus and Ruminiclostridium, respectively, at the genus level. The expression levels of brain-derived neurotrophic factor (BDNF), postsynaptic Arc and PSD95, and the mature neuronal marker NeuN in the hippocampus were increased after BWF administration, which was induced by the activation of the ERK/CREB signaling pathway and histone H3 acetylation. A similar increase in cognitive performance-related hippocampal BDNF expression in SAMP8 mice was observed after the oral administration of starch prepared from BWF. Therefore, the long-term administration of BWF suppresses cognitive decline by increasing hippocampal BDNF production in SAMP8 mice.

Aboveground plant-to-plant communication reduces root nodule symbiosis and soil nutrient concentrations.

Aboveground communication between plants is well known to change defense traits in leaves, but its effects on belowground plant traits and soil characteristics have not been elucidated. We hypothesized that aboveground plant-to-plant communication reduces root nodule symbiosis via induction of bactericidal chemical defense substances and changes the soil nutrient environment. Soybean plants were exposed to the volatile organic compounds (VOCs) from damaged shoots of Solidago canadensis var. scabra, and leaf defense traits (total phenolics, saponins), root saponins, and root nodule symbiosis traits (number and biomass of root nodules) were measured. Soil C/N ratios and mineral concentrations were also measured to estimate the effects of resource uptake by the plants. We found that total phenolics were not affected. However, plants that received VOCs had higher saponin concentrations in both leaves and roots, and fewer root nodules than untreated plants. Although the concentrations of soil minerals did not differ between treatments, soil C/N ratio was significantly higher in the soil of communicated plants. Thus, the aboveground plant-to-plant communication led to reductions in root nodule symbiosis and soil nutrient concentrations. Our results suggest that there are broader effects of induced chemical defenses in aboveground plant organs upon belowground microbial interactions and soil nutrients, and emphasize that plant response based on plant-to-plant communications are a bridge between above- and below-ground ecosystems.

Effectiveness of an Out-of-Pocket Cost Removal Intervention on Health Check Attendance in Japan.

Annual health checks are important for identifying individuals at high risk for cardiometabolic diseases. However, there are socioeconomic disparities in health check attendance rates, and an intervention to lower financial barriers could be useful for increasing health check utilization. In this study, we aimed to evaluate the effectiveness of an out-of-pocket cost removal intervention on health check attendance in Japan. Data were obtained on beneficiaries of the National Health Insurance system of Yokohama City, Kanagawa Prefecture, Japan. In 2018, Yokohama started an intervention to remove out-of-pocket costs for specific health checks for all National Health Insurance beneficiaries. We analyzed data from 2015-2018 (131,295 people aged 40-74 years; 377,660 observations). A generalized estimating equation showed that people were more likely to receive specific health checks in 2018 (after the out-of-pocket cost removal intervention started) than in 2017 (immediately before the intervention; odds ratio [95% confidence interval] = 1.167 [1.149-1.185]), after adjusting for age, gender, tax exemption, and residential area. Stratified analyses revealed that the effectiveness of the out-of-pocket cost removal intervention was greater among the older age group and those who did not receive a tax exemption (i.e., those with relatively higher income). The present study showed that the out-of-pocket cost removal intervention could promote specific health check utilization. This indicates that removing financial barriers could motivate people's behavior regarding health check attendance.