Exposure to an enriched environment increases neurogenesis in the dentate gyrus of adult rodents. Environmental enrichment, however, typically consists of many components, such as expanded learning opportunities, increased social interaction, more physical activity and larger housing. We attempted to separate components by assigning adult mice to various conditions: water-maze learning (learner), swim-time-yoked control (swimmer), voluntary wheel running (runner), and enriched (enriched) and standard housing (control) groups. Neither maze training nor yoked swimming had any effect on bromodeoxyuridine (BrdU)-positive cell number. However, running doubled the number of surviving newborn cells, in amounts similar to enrichment conditions. Our findings demonstrate that voluntary exercise is sufficient for enhanced neurogenesis in the adult mouse dentate gyrus.

http://www.neurogenesisresearch.com/Runing_and_Neurogenesis_Nat.pdf

Running increases cell proliferation and neurogenesis in the adult mouse dentate gyrus.

Running increases neurogenesis in the dentate gyrus of the hippocampus, a brain structure that is important for memory function. Consequently, spatial learning and long-term potentiation (LTP) were tested in groups of mice housed either with a running wheel (runners) or under standard conditions (controls). Mice were injected with bromodeoxyuridine to label dividing cells and trained in the Morris water maze. LTP was studied in the dentate gyrus and area CA1 in hippocampal slices from these mice. Running improved water maze performance, increased bromodeoxyuridine-positive cell numbers, and selectively enhanced dentate gyrus LTP. Our results indicate that physical activity can regulate hippocampal neurogenesis, synaptic plasticity, and learning.

/pdf/running-enhances-neurogenesis-learning-and-long-term-3fsv8gc8b9.pdf

Running enhances neurogenesis, learning, and long-term potentiation in mice

Exercise: a behavioral intervention to enhance brain health and plasticity

Neuronal plasticity is a central theme of modern neurobiology, from cellular and molecular mechanisms of synapse formation in Drosophila to behavioural recovery from strokes in elderly humans. Although the methods used to measure plastic responses differ, the stimuli required to elicit plasticity are thought to be activity-dependent. In this article, we focus on the neuronal changes that occur in response to complex stimulation by an enriched environment. We emphasize the behavioural and neurobiological consequences of specific elements of enrichment, especially exercise and learning.

Neural consequences of environmental enrichment.

Context: Dementia is common, costly, and highly age related. Little attention has been paid to the identification of modifiable lifestyle habits for its prevention. Objective: To explore the association between physical activity and the risk of cognitive impairment and dementia. Design, Setting, and Subjects: Data come from a community sample of 9008 randomly selected men and women 65 years or older, who were evaluated in the 1991-1992 Canadian Study of Health and Aging, a prospective cohort study of dementia. Of the 6434 eligible subjects who were cognitively normal at baseline, 4615 completed a 5-year follow-up. Screening and clinical evaluations were done at both waves of the study. In 1996-1997, 3894 remained without cognitive impairment, 436 were diagnosed as having cognitive impairment‐no dementia, and 285 were diagnosed as having dementia. MainOutcomeMeasure: Incident cognitive impairment and dementia by levels of physical activity at baseline. Results: Compared with no exercise, physical activity was associated with lower risks of cognitive impairment, Alzheimer disease, and dementia of any type. Significant trends for increased protection with greater physical activity were observed. High levels of physical activity were associated with reduced risks of cognitive impairment (age-, sex-, and education-adjusted odds ratio, 0.58; 95% confidence interval, 0.41-0.83), Alzheimer disease (odds ratio, 0.50; 95% confidence interval, 0.28-0.90), and dementia of any type (odds ratio, 0.63; 95% confidence interval, 0.40-0.98). Conclusion: Regular physical activity could represent an important and potent protective factor for cognitive decline and dementia in elderly persons. Arch Neurol. 2001;58:498-504

/pdf/physical-activity-and-risk-of-cognitive-impairment-and-4oegy3td3q.pdf

Physical activity and risk of cognitive impairment and dementia in elderly persons.

Physical exercise induces FGF-2 and its mRNA in the hippocampus

Spatial learning and physical activity contribute to the induction of fibroblast growth factor: neural substrates for increased cognition associated with exercise

Brain-derived neurotrophic factor (BDNF) promotes neuron survival, enhances sprouting, protects neurons against insult, and may be involved in several aspects of learning and memory. In this study, rats trained to locate a submerged platform in a water maze had elevated levels of BDNF messenger ribonucleic acid (mRNA) in the hippocampus (p .05). These findings suggest that learning can impact BDNF mRNA expression localized to the brain areas involved in the processing of spatial information. Furthermore, behaviors such as physical activity and learning may help maintain and protect neurons at risk in aging and neurodegenerative disease via increased BDNF expression.

Vannarith So

Papers

Physical exercise induces FGF-2 and its mRNA in the hippocampus

Spatial learning and physical activity contribute to the induction of fibroblast growth factor: neural substrates for increased cognition associated with exercise

Learning upregulates brain-derived neurotrophic factor messenger ribonucleic acid: a mechanism to facilitate encoding and circuit maintenance?