Abnormalities in motor adaptation to different types of perturbations in schizophreniaperturbations in schizophrenia.

Schizophrenia is a mental health disorder that often includes psychomotor disturbances, impacting how individuals adjust their motor output based on the cause of motor errors. While previous motor adaptation studies on individuals with schizophrenia have largely focused on large and consistent perturbations induced by abrupt experimental manipulations, such as donning prism goggles, the adaptation process to random perturbations, either caused by intrinsic motor noise or external disturbances, has not been examined - despite its ecological relevance. Here, we used a unified behavioral task paradigm to examine motor adaptation to perturbations of three causal structures among individuals in the remission stage of schizophrenia, youth with ultra-high risk of psychosis, adults with active symptoms, and age-matched controls. Results showed that individuals with schizophrenia had reduced trial-by-trial adaptation and large error variance when adapting to their own motor noise. When adapting to random but salient perturbations, they showed intact adaptation and normal causal inference of errors. This contrasted with reduced adaptation to large yet consistent perturbations, which could reflect difficulties in forming cognitive strategies rather than the often-assumed impairments in procedural learning or sense of agency. Furthermore, the observed adaptation effects were correlated with the severity of positive symptoms across the diagnosis groups. Our findings suggest that individuals with schizophrenia face challenges in accommodating intrinsic perturbations when motor errors are ambiguous but adapt with intact causal attribution when errors are salient.

Geographic differences and variation of functional components of brown rice in 690 mini-core collections from global germplasms.

Objective: To understand the geographic differences and variations in the functional components of brown rice cores collected from global rice germplasms. Methods: Four functional components, γ-aminobutyric acid (GABA), resistant starch (RS), total flavonoids, and alkaloids, in brown rice from 690 mini-core collections from 31 countries from five continents and the International Rice Research Institute, were analyzed using a spectrophotometry colorimetric method, and the results were statistically validated. Conclusion: The highest average amounts of functional components were obtained in Asian germplasms, except for GABA, and total flavonoids were highest in brown rice from Europe and Oceania, followed by Asia. The highest coefficient of variation for GABA was observed in Asia; that for RS and total flavonoids was observed in Africa, followed by Asia; and that for alkaloids was observed in America, followed by Asia. Overall, Asian countries were the most prominent and representative zones with the highest genotypic potential for functional components of brown rice. Forty-one rice accessions with enriched functional components originated mostly from biodiversity-rich areas in China, followed by those in the Philippines. Late sowing favored the enrichment of these components in brown rice. The current study provides a reference for rice breeding with enriched functional constituents, and guidelines for screening functional rice that could be used for human chronic disease research.

Genome-Wide Association Study Reveals the Genetic Basis of Total Flavonoid Content in Brown Rice.

Flavonoids have anti-inflammatory, antioxidative, and anticarcinogenic effects. Breeding rice varieties rich in flavonoids can prevent chronic diseases such as cancer and cardio-cerebrovascular diseases. However, most of the genes reported are known to regulate flavonoid content in leaves or seedlings. To further elucidate the genetic basis of flavonoid content in rice grains and identify germplasm rich in flavonoids in grains, a set of rice core collections containing 633 accessions from 32 countries was used to determine total flavonoid content (TFC) in brown rice. We identified ten excellent germplasms with TFC exceeding 300 mg/100 g. Using a compressed mixed linear model, a total of 53 quantitative trait loci (QTLs) were detected through a genome-wide association study (GWAS). By combining linkage disequilibrium (LD) analysis, location of significant single nucleotide polymorphisms (SNPs), gene expression, and haplotype analysis, eight candidate genes were identified from two important QTLs (qTFC1-6 and qTFC9-7), among which LOC_Os01g59440 and LOC_Os09g24260 are the most likely candidate genes. We also analyzed the geographic distribution and breeding utilization of favorable haplotypes of the two genes. Our findings provide insights into the genetic basis of TFC in brown rice and could facilitate the breeding of flavonoid-rich varieties, which may be a prevention and adjuvant treatment for cancer and cardio-cerebrovascular diseases.