Swimming exercise increases neurogenesis in the subventricular zone, and upregulates NGF and Synapsin I level in the olfactory bulb of the adult rats

Abstract

In this study, we investigated the effects of 8-weeks of swimming exercise on neurogenesis in the subventricular zone (SVZ) and on the levels of nerve growth factor (NGF) and synapsin I protein in the olfactory bulb (OB) of adult rats at a series of relevant time points (2 days, 1 week, 2 weeks, 4 weeks, 3 months, and 6 months). Ninety-six male Sprague Dawley rats were divided into 2 groups: (1) a control group (COG; n = 48, n = 8 for each time point) and (2) a swimming exercise group (SEG; total n = 48; n = 8 for each time point). SEG performed swimming exercise for 5 days per week over a period of 8 weeks. We found that the number of 5-bromo-2’-deoxyuridine-5’-monophosphate (BrdU)- and doublecortin (DCX)-positive cells was significantly higher in SEG than in COG at all time points (Day 2, Week 1, Week 2, Week 4, Month 3, and Month 6; p < 0.001). Furthermore, NGF and synapsin I protein levels were significantly higher in SEG on Day 2, and Weeks 1, 2, and 4 than in COG (p < 0.05 for each time point). Our findings suggest that regular swimming exercise in adult rats increases neurogenesis, neuronal survival, and neuronal maintenance in the SVZ; furthermore, swimming exercise increases the levels of NGF and synapsin I in the OB.

Aerobic Exercise Preserves Olfaction Function in Individuals with Parkinson’s Disease

“…The significant difference in UPSIT scores between the exercise and nonexercise groups suggests that aerobic exercise may be altering neurophysiological pathways or neurotransmitter function that regulate the physiologic or cognitive processes controlling olfaction [19, 20]. While we are not able to determine the exact mechanism underlying a sparring of olfaction, it is plausible, based on results from animal exercise studies, that the physiological changes (i.e., increased neurotrophins, neurotransmitters, and improved functional connectivity) and increases in cerebral blood flow associated with intensive aerobic exercise may have facilitated function of the olfaction system centrally or improved the higher level cognitive processes associated with odor detection [21, 28, 29].…”

“…There is preliminary evidence that exercise may have a positive impact on olfaction. In an 8-week swimming intervention in adult rats, synapsin and neurotrophic factors in the olfactory bulb were greater in the exercise group than the nonexercise control group [19]. In a longitudinal study of over 1800 older adults, those who exercised three times per week were at a lower risk of developing olfaction dysfunction over a 10-year follow-up period [20].…”

Dysfunction of the neurovascular unit in ischemic stroke and neurodegenerative diseases: An aging effect

“…Therefore, medication regimens should be carefully adjusted to achieve the best protection for aged NVU. In addition, physical exercises, such as running and swimming, have been demonstrated to stimulate neurogenesis (Chae et al, 2014; van Praag et al, 1999). Indeed, lifestyle shift could be the most efficient and economical strategy to prevent the incidence of stroke and to ameliorate ischemic brain injury in the geriatric population.…”

Factors that influence adult neurogenesis as potential therapy

“…They showed that neither swimming, nor maze training improved cell proliferation and neurogenesis in the dentate gyrus, however, a voluntary exercise in a running wheel doubled the number of proliferating cells and net neurogenesis in the dentate gyrus [ 157 ]. In contrast, an independent study showed that exposing rats to regular swimming exercise resulted in an increase in the progenitor cell proliferation and maturation in the SVZ [ 155 ]. Species specific differences, that is rats instead of mice, and also the frequency or the duration of swimming exercise may account for the discrepancies in findings on the extent of physical activity required to elicit augmented neurogenesis.…”