Effect of perinatally supplemented flavonoids on brain structure, circulation, cognition, and metabolism in C57BL/6J mice.

Evidence suggests that flavanol consumption can beneficially affect cognition in adults, but little is known about the effect of flavanol intake early in life. The present study aims to assess the effect of dietary flavanol intake during the gestational and postnatal period on brain structure, cerebral blood flow (CBF), cognition, and brain metabolism in C57BL/6J mice. Female wild-type C57BL/6J mice were randomly assigned to either a flavanol supplemented diet or a control diet at gestational day 0. Male offspring remained on the corresponding diets throughout life and performed cognitive and behavioral tests during puberty and adulthood assessing locomotion and exploration (Phenotyper and open field), sensorimotor integration (Rotarod and prepulse inhibition), and spatial learning and memory (Morris water maze, MWM). Magnetic resonance spectroscopy and imaging at 11.7T measured brain metabolism, CBF, and white and gray matter integrity in adult mice. Biochemical and immunohistochemical analyses evaluated inflammation, synaptic plasticity, neurogenesis, and vascular density. Cognitive and behavioral tests demonstrated increased locomotion in Phenotypers during puberty after flavanol supplementation (p = 0.041) but not in adulthood. Rotarod and prepulse inhibition demonstrated no differences in sensorimotor integration. Flavanols altered spatial learning in the MWM in adulthood (p = 0.039), while spatial memory remained unaffected. Additionally, flavanols increased diffusion coherence in the visual cortex (p = 0.014) and possibly the corpus callosum (p = 0.066) in adulthood. Mean diffusion remained unaffected, a finding that corresponds with our immunohistochemical data showing no effect on neurogenesis, synaptic plasticity, and vascular density. However, flavanols decreased CBF in the cortex (p = 0.001) and thalamus (p = 0.009) in adulthood. Brain metabolite levels and neuroinflammation remained unaffected by flavanols. These data suggest that dietary flavanols results in subtle alterations in brain structure, locomotor activity and spatial learning. Comparison of these data to published findings in aging or neurodegeneration suggests that benefits of dietary flavanols may increase with advancing age and in disease.

Impact of dietary n-3 polyunsaturated fatty acids on cognition, motor skills and hippocampal neurogenesis in developing C57BL/6J mice.

Maternal intake of omega-3 polyunsaturated fatty acids (n-3 PUFA) is critical during perinatal development of the brain. Docosahexaenoic acid (DHA) is the most abundant n-3 PUFA in the brain and influences neuronal membrane function and neuroprotection. The present study aims to assess the effect of dietary n-3 PUFA availability during the gestational and postnatal period on cognition, brain metabolism and neurohistology in C57BL/6J mice. Female wild-type C57BL/6J mice at day 0 of gestation were randomly assigned to either an n-3 PUFA deficient diet (0.05% of total fatty acids) or an n-3 PUFA adequate diet (3.83% of total fatty acids) containing preformed DHA and its precursor α-linolenic acid. Male offspring remained on diet and performed cognitive tests during puberty and adulthood. In adulthood, animals underwent (31)P magnetic resonance spectroscopy to assess brain energy metabolites. Thereafter, biochemical and immunohistochemical analyses were performed assessing inflammation, neurogenesis and synaptic plasticity. Compared to the n-3 PUFA deficient group, pubertal n-3 PUFA adequate fed mice demonstrated increased motor coordination. Adult n-3 PUFA adequate fed mice exhibited increased exploratory behavior, sensorimotor integration and spatial memory, while neurogenesis in the hippocampus was decreased. Selected brain regions of n-3 PUFA adequate fed mice contained significantly lower levels of arachidonic acid and higher levels of DHA and dihomo-γ-linolenic acid. Our data suggest that dietary n-3 PUFA can modify neural maturation and enhance brain functioning in healthy C57BL/6J mice. This indicates that availability of n-3 PUFA in infant diet during early development may have a significant impact on brain development.

Effects of specific multi-nutrient enriched diets on cerebral metabolism, cognition and neuropathology in AßPPswe-PS1dE9 mice.

Recent studies have focused on the use of multi-nutrient dietary interventions in search of alternatives for the treatment and prevention of Alzheimer's disease (AD). In this study we investigated to which extent long-term consumption of two specific multi-nutrient diets can modulate AD-related etiopathogenic mechanisms and behavior in 11-12-month-old AßPPswe-PS1dE9 mice. Starting from 2 months of age, male AßPP-PS1 mice and wild-type littermates were fed either a control diet, the DHA+EPA+UMP (DEU) diet enriched with uridine monophosphate (UMP) and the omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), or the Fortasyn® Connect (FC) diet enriched with the DEU diet plus phospholipids, choline, folic acid, vitamins and antioxidants. We performed behavioral testing, proton magnetic resonance spectroscopy, immunohistochemistry, biochemical analyses and quantitative real-time PCR to gain a better understanding of the potential mechanisms by which these multi-nutrient diets exert protective properties against AD. Our results show that both diets were equally effective in changing brain fatty acid and cholesterol profiles. However, the diets differentially affected AD-related pathologies and behavioral measures, suggesting that the effectiveness of specific nutrients may depend on the dietary context in which they are provided. The FC diet was more effective than the DEU diet in counteracting neurodegenerative aspects of AD and enhancing processes involved in neuronal maintenance and repair. Both diets elevated interleukin-1ß mRNA levels in AßPP-PS1 and wild-type mice. The FC diet additionally restored neurogenesis in AßPP-PS1 mice, decreased hippocampal levels of unbound choline-containing compounds in wild-type and AßPP-PS1 animals, suggesting diminished membrane turnover, and decreased anxiety-related behavior in the open field behavior. In conclusion, the current data indicate that specific multi-nutrient diets can influence AD-related etiopathogenic processes. Intervention with the FC diet might be of interest for several other neurodegenerative and neurological disorders.