Neurobehavioral Effects of Fermented Rice Bran Extract in Zebrafish Larvae Model

Rice bran (RB) is a promising food ingredient that can improve biological function. In this study, we investigated the effects of RB, both unfermented (RB30) and fermented (RBF30), with five different microorganisms on the neurobehavioral activity in zebrafish larvae. Analytical methods such as LC-UV and LC-MS were performed for the analysis of RB30 and RBF30 extracts. Interestingly, niacin content, which is known to improve brain functions such as cognition and emotion, was found to be higher in RBF30 than in RB30. Furthermore, niacin content was highly increased in the RBF30-exposed fish, compared to those in the control fish. Therefore, we profiled behavioral patterns and various neurochemistry in zebrafish larvae following supplementation with RBF30 as well as performed calcium imaging on Tg (huC:GAL4-VP16); (UAS:GCaMP7a) zebrafish larvae to determine the correlation of neural activity. RBF30 revealed greater stimulation of locomotor activity without negatively affecting decision-making behavior in zebrafish larvae, as compared to RB30 or niacin. Its behavioral activation is mainly linked with the elevations of neural activity and several neurochemicals such as serotonergic and dopaminergic systems that are implicated in the control of anxiety and stress. Taken together, these results suggest that RBF30 could be a food material that improves the behavioral health by modulating neural activity and brain neurochemistry.