Emerging research demonstrates that exercise is favorably associated with several cognitive outcomes, including episodic memory function. The majority of the mechanistic work describing the underlying mechanisms of this effect has focused on chronic exercise engagement. Such mechanisms include, e.g., chronic exercise-induced neurogenesis, gliogenesis, angiogenesis, cerebral circulation, and growth factor production. Less research has examined the mechanisms through which acute (vs. chronic) exercise subserves episodic memory function. The purpose of this review is to discuss these potential underlying mechanisms, which include, e.g., acute exercise-induced (via several pathways, such as vagus nerve and muscle spindle stimulation) alterations in neurotransmitters, synaptic tagging/capturing, associativity, and psychological attention.
Authors:A. Bravo, L. Ponce, P. Párraga, R. Oliva, and K. Proaño
In this study we analyzed the performance of three wheat varieties in relation to gluten content under high-altitude growing conditions in the Andes of Ecuador. A field experiment was conducted at 3058 meters above sea level during 2009 using adapted wheat cultivar Cojitambo, cv. Carnavalero, and cv. Sibambe. Transcript accumulations of High Molecular Weight Glutenin Subunits (HMW-GS) genes were also evaluated during grain development using qRT-PCR. We recorded the expression profile of HMW-GS genes during 41 days and showed a coordinated pattern of induction with significant higher levels at 82–86 days. Transcript accumulation of 1Dx5, 1Dy10, 1Bx7, 1Ax1, and 1By9 genes were analyzed in more details during this period. The assay highlighted the specific contribution of 1Bx7, 1Dy10, and 1Dx5 during gluten formation in Ecuadorian wheat varieties. Under Andean highlands conditions, cv. Carnavalero showed the higher values of total agglomerated protein upon hydration and higher levels of expression of particular HMW-GS genes. The data suggest a correlation between wet gluten content and HMW-GS genes expression. Our study contributes to understand gluten formation in wheat endosperm under high-altitude conditions in the Andes.
Authors:M. Jung, I. Brizes, S. Wages, P. Ponce, M. Kang, and P.D. Loprinzi
No previous studies have evaluated the potential combined effects of acute exercise and acute hypoxia exposure on memory function, which was the purpose of this study. Twenty-five participants (Mage = 21.2 years) completed two laboratory visits in a counterbalanced order, involving 1) acute exercise (a 20-min bout of moderate-intensity exercise) and then 30 min of exposure to hypoxia (FIO2 = 0.12), and 2) exposure to hypoxia alone (FIO2 = 0.12) for 30 min. Following this, participants completed a cued-recall and memory interference task (AB/AC paradigm), assessing cued-recall memory (recall 1 and recall 2) and memory interference (proactive and retroactive interference). For cued-recall memory, we observed a significant main effect for condition, with Exercise + Hypoxia condition having significantly greater cued-recall performance than Hypoxia alone. Memory interference did not differ as a function of the experimental condition. This experiment demonstrates that engaging in an acute bout of exercise prior to acute hypoxia exposure had an additive effect in enhancing cued-recall memory performance.