Effects of chronic treadmill running on neurogenesis in the dentate gyrus of the hippocampus of adult rat.
ABSTRACT Proliferating astrocytes and proliferating neuroblasts have been observed in the subgranular zone (SGZ) of the dentate gyrus (DG) in the hippocampus of adult rats under normal conditions. However, whether these proliferating cells are stimulated by running has not been determined. Using immunohistochemical techniques, we examined the effects of chronic treadmill running on proliferating astrocytes (PCNA+/GFAP+ cells), proliferating neuroblasts (PCNA+/DCX+ cells) and newly generated postmitotic neurons (DCX+/NeuN+ cells) in the DG of the hippocampus of adult rats and also characterized the morphological features of PCNA+/GFAP+ cells and PCNA+/DCX+ cells. PCNA+/GFAP+ cells with few processes and PCNA+/DCX+ cells without long processes were detected in the SGZ, and we determined that these are morphological features of the astrocytes and neuroblasts with proliferative ability. Chronic treadmill running (at a speed of 22 m/min, 30 min/days for 7 days) significantly increased the numbers of PCNA+/GFAP+ cells and DCX+/NeuN+ cells, and the number of PCNA+/DCX+ cells tended to increase by chronic treadmill running. These results indicate that chronic treadmill running stimulates the proliferation of astrocytes in the SGZ. Furthermore, the present study indicates that chronic treadmill running increases DCX+/NeuN+ cells that are detected in a transient stage during the neuronal maturation process. These events may be the cellular basis mediating both running-induced increases of new neurons in the DG of the hippocampus and running-induced improvement of learning and memory functions of adult rats.
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ABSTRACT: This study was designed to determine the relationship between physical activity and the task-switching aspect of executive function by investigating the modulating roles of age, modality of physical activity, and type of cognitive function using behavioral and event-related potential (ERP) assessments. Sixty-four participants were assigned to one of four groups based on age and history of physical activity: older adults performing endurance exercise (OEE), older adults practicing Tai Chi Chuan (OTC), older adults with a sedentary lifestyle (OSL), and young adults (YA). Study participants completed a task-switching task under homogeneous and heterogeneous conditions while ERPs were recorded. The results revealed that YA had shortest reaction times compared with the three older adults groups, with OSL exhibiting the longest reaction time. YA also exhibited shorter P3 latency than OSL. No differences were observed in P3 amplitude between YA, OEE, and OTC; however, all three groups had significantly larger P3 amplitude compared with OSL in both task conditions. In conclusion, age and participation in physical activity influence the relationship between physical activity and task-switching, and a positive relationship was observed regardless of the modality of physical activity and type of cognitive function. Our ERP findings support the model of the scaffolding theory of aging and cognition (STAC) and suggest that regular participation in endurance exercise and Tai Chi Chuan may have equivalent beneficial effects on cognition at the behavioral and neuroelectric levels.Frontiers in Aging Neuroscience 10/2014; 6:295. DOI:10.3389/fnagi.2014.00295 · 2.84 Impact Factor
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ABSTRACT: In this chapter, we review literature that examines the association among physical activity, aerobic fitness, cognition, and the brain in elementary school children (ages 7-10 years). Specifically, physical activity and higher levels of aerobic fitness in children have been found to benefit brain structure, brain function, cognition, and school achievement. For example, higher fit children have larger brain volumes in the basal ganglia and hippocampus, which relate to superior performance on tasks of cognitive control and memory, respectively, when compared to their lower fit peers. Higher fit children also show superior brain function during tasks of cognitive control, better scores on tests of academic achievement, and higher performance on a real-world street crossing task, compared to lower fit and less active children. The cross-sectional findings are strengthened by a few randomized, controlled trials, which demonstrate that children randomly assigned to a physical activity intervention group show greater brain and cognitive benefits compared to a control group. Because these findings suggest that the developing brain is plastic and sensitive to lifestyle factors, we also discuss typical structural and functional brain maturation in children to provide context in which to interpret the effects of physical activity and aerobic fitness on the developing brain. This research is important because children are becoming increasingly sedentary, physically inactive, and unfit. An important goal of this review is to emphasize the importance of physical activity and aerobic fitness for the cognitive and brain health of today's youth.Monographs of the Society for Research in Child Development 12/2014; 79(4):25-50. DOI:10.1111/mono.12129 · 5.50 Impact Factor
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ABSTRACT: Se reconoce que el ejercicio puede aumentar la neurogénesis adulta y este fenómeno podría evidenciarse en diferentes niveles (comportamental, celular, electrofisiológico). El objetivo del estudio fue evaluar el efecto de la estimulación de la neurogénesis hipocampal mediante el ejercicio, sobre la memoria de trabajo evaluada mediante una tarea de laberinto en T en ratas macho adultas de la sepa Wistar. Se utilizó un diseño experimental de dos grupos en el cual un grupo experimental GE (n = 12) fue sometido a un programa de ejercicio forzado durante 5 días, al mismo tiempo que se administró un marcador de síntesis de ADN (Bromo-deoxi-uridina [BrdU](50 mg/kg IP.), los animales control GC (n = 9) no fueron expuestos al ejercicio pero se les administró igual dosis de BrdU. Tres (3) animales (GE = 2; GC = 1) se sometieron a cirugía de implantación de electrodos en la corteza frontal medial (+3,0 mm AP; ± 0.5 mm ML; -3.0mm DV) e hipocampo (-3.0mm AP; ± 1.8mm ML; -3.5mm DV) para registro electroencefalográfico durante la ejecución en el laberinto en T. 6-8 semanas después de la aplicación del ejercicio se evaluó la memoria de trabajo en laberinto en T y se analizaron cuatro (4) días de elección evaluando la alternancia de las opciones como indicador de memoria de trabajo. No se encontró diferencia comportamental entre los grupos experimental y control en variables comportamentales (alternancia, índice de preferencia, tiempo de respuesta, tiempo de ensayo, consumo de comida). El registro electroencefalográfico de los animales no mostró una tendencia a la coherencia entre las áreas registradas, siendo éste un indicador fisiológico del proceso de elección. En cuanto a la cantidad de nuevas neuronas no se encontraron diferencias por grupos.12/2014, Degree: Master, Supervisor: Fernando Cardenas; Manuel Rojas