Active neurons increase their energy supply by dilating nearby arterioles and capillaries to increase blood flow, but the mechanisms underlying neurovascular coupling are debated. In this paper, the authors show that different calcium-dependent signaling pathways regulate blood flow at the level of capillary pericytes and arteriole smooth muscle. Active neurons increase their energy supply by dilating nearby arterioles and capillaries. This neurovascular coupling underlies blood oxygen level–dependent functional imaging signals, but its mechanism is controversial. Canonically, neurons release glutamate to activate metabotropic glutamate receptor 5 (mGluR5) on astrocytes, evoking Ca2+ release from internal stores, activating phospholipase A2 and generating vasodilatory arachidonic acid derivatives. However, adult astrocytes lack mGluR5, and knockout of the inositol 1,4,5-trisphosphate receptors that release Ca2+ from stores does not affect neurovascular coupling. We now show that buffering astrocyte Ca2+ inhibits neuronally evoked capillary dilation, that astrocyte [Ca2+]i is raised not by release from stores but by entry through ATP-gated channels, and that Ca2+ generates arachidonic acid via phospholipase D2 and diacylglycerol lipase rather than phospholipase A2. In contrast, dilation of arterioles depends on NMDA receptor activation and Ca2+-dependent NO generation by interneurons. These results reveal that different signaling cascades regulate cerebral blood flow at the capillary and arteriole levels.
This study was designed to assess whether the combined effect of taste-congruent and incongruent extrinsic visual cues presented in virtual reality (VR) influences the perception of sweetness and product liking. Three VR environments (sweet-congruent, sweet-incongruent, and neutral) were created based on the evidence in existing literature. Participants tasted the same beverage in three VR environments and evaluated the environment and beverage liking, as well as perceived taste intensity (sweetness, sourness, and bitterness), congruency, comfort, and environment vividness. Frontal EEG alpha asymmetry (FAA) was also recorded as a complementary physiological measurement of overall liking. The results showed that the perceived sweetness of the beverage was significantly elevated in a sweet-congruent environment versus the other environments. Visual-taste congruency did not seem to have an effect on beverage liking and overall liking, whereas an increase in environment liking was found in the incongruent environment versus the other environments. These findings confirmed the significant influence of taste-specific visual cues on flavour perception, while the successful use of VR in the study provided insight into future applications of taste-specific VR environment in the modulation of flavour perception and sugar reduction.
Diet-related chronic disease is a global health epidemic giving rise to a high incidence of morbidity and mortality. With the rise of the digital revolution, there has been increased interest in using digital technology for eating behavioural change as a mean of diet-related chronic disease prevention. However, evidence on digital dietary behaviour change is relatively scarce. To address this problem, this review considers the digital interventions currently being used in dietary behaviour change studies. A literature search was conducted in databases like PubMed, Cochrane Library, CINAHL, Medline, and PsycInfo. Among 119 articles screened, 15 were selected for the study as they met all the inclusion criteria according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) search strategy. Four primary digital intervention methods were noted: use of personal digital assistants, use of the internet as an educational tool, use of video games and use of mobile phone applications. The efficiency of all the interventions increased when coupled with tailored feedback and counselling. It was established that the scalable and sustainable properties of digital interventions have the potential to bring about adequate changes in the eating behaviour of individuals. Further research should concentrate on the appropriate personalisation of the interventions, according to the requirements of the individuals, and proper integration of behaviour change techniques to motivate long-term adherence.
1 April 2021 in International Journal of Food Design
Immunocompromised post-bone marrow transplant patients must follow a restrictive diet after discharge to avoid microbiological risks in food. Despite the apparent health considerations, these restrictions can sometimes create confusion and apprehension during home meal preparation which has a negative impact on patients’ social dining experiences with families and friends and ultimately leads to adverse health effects such as appetite and weight loss. A user-friendly meal guidebook, specifically designed to fit patient’s needs, was developed to ensure a smooth transition from controlled hospital food to home-cooked meals without compromises in food safety and pleasure. With this guidebook, the objective of this uncommon collaboration between chefs and health professionals was to provide clear instructions to the patients on their diet and adapted recipes (six starters, eight main dishes and eight desserts) easy to do and share with the whole family. This design project represents a unique approach to addressing the food and nutrition needs of these transplant patients. Thus, this article presents an example of a multi-actor collaboration between health and culinary professionals who combined their expertise to help the patients feel less marginalized after their hospitalization and to support their recovery by providing adapted recipes that they can share with their family.