Extended Voluntary Running Inhibits Exercise-Induced Adult Hippocampal Progenitor Proliferation in the Spontaneously Hypertensive Rat

Abstract

. Extended voluntary running inhibits exercise induced adult hippocampal progenitor proliferation in the spontaneously hypertensive rat. J Neurophysiol 93: 2406 -2414, 2005. First published December 22, 2004 doi:10.1152/ jn.01085.2004. Previous work has shown that voluntary running increases cell proliferation and neurogenesis in the dentate gyrus of the adult hippocampus. Here we report that long-term running for 24 days results in a down-regulation of hippocampal progenitor proliferation to one-half the level of nonrunning controls compared with a fivefold increase in progenitor proliferation seen after 9 days of voluntary running (short-term running). The negative effects seen on proliferation after 24 days of running were prevented by restricting daily running distances (by 30 -50%) during 24 days. Long-term running for 24 days increases the response of the hypothalamicpituitary-adrenal axis, with an increase in adrenal gland weight and increased plasma corticosterone levels, as well as decreased thymus weight, indicating a stress response as a possible mediator of decreased progenitor proliferation. Furthermore, the negative effects seen on the observed stress response after 24 days of running were prevented by restricting daily running distance. Short-term running did not alter these stress parameters compared with nonrunning controls. However, it increased phosphorylated cyclic AMP response element binding protein (pCREB) in the dentate gyrus, an increase that was not seen in nonrunning controls or after 24 days of running. Taken together, these data suggest that voluntary running does not always enhance proliferation and that the decrease in progenitor proliferation seen in long-term running is possibly mediated by mechanisms involving a stress response in the animal. However, a moderate level of long-term running was able to prevent the negative stress-related changes seen in unrestricted long-term running.

Exercise as a pro-cognitive, pro-neurogenic and anti-inflammatory intervention in transgenic mouse models of Alzheimer’s disease

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Cerebral Vasomotor Reactivity during Hypo- and Hypercapnia in Sedentary Elderly and Masters Athletes

“…It is possible that life-long high volume, high intensity aerobic exercise training may not be optimal for protecting brain perfusion from the age-related decline. 24,25 In this regard, our recent study demonstrated that 3 months of moderate aerobic exercise training increased global CBF in the elderly women over 60 years. 26 Thus, further longitudinal studies are needed to determine if indeed there is a 'dose-response' relationship between exercise training and brain perfusion.…”

Voluntary running rescues adult hippocampal neurogenesis after irradiation of the young mouse brain

“…Irradiation-induced decreases in neurogenesis have been linked to significant hyperactivity and cognitive impairments (16)(17)(18)(19). Voluntary running is known to increase cell proliferation and neurogenesis in the hippocampus of rodents (20)(21)(22), with concomitant improvements in cognitive function, spatial memory, and learning (23)(24)(25). Exercise also significantly alters the microenvironment of the hippocampus in rodents, with increased growth factor expression (26,27) and synaptic plasticity (28,29).…”