Swimming exercise ameliorates mood disorder and memory impairment by enhancing neurogenesis, serotonin expression, and inhibiting apoptosis in social isolation rats during adolescence

Abstract

Social isolation during adolescence is associated with anxiety, depression, and memory impairment. Exercise has been reported as a positive effect on brain function, especially hippocampus. The present study examined the effect of swimming exercise on apoptosis, cell proliferation, and serotonin expression in social isolation rats during adolescence stage. Social isolation started at postnatal day 21 and continued for 6 weeks. The rats in the swimming group were forced to swim for 60 min once daily during 6 days per week for 6 consecutive weeks. The rats in the social isolation during adolescence showed anxiety, depression, short-term memory impairment. Social isolation facilitated apoptosis and inhibited cell proliferation and differentiation. Social isolation suppressed expression of serotonin, brain-derived neurotrophic factor, and tyrosine kinase B. Swimming exercise alleviated anxiety, depression, short-term impairment. Swimming exercise suppressed apoptosis, enhanced neurogenesis, and increased serotonin expression. In our study, swimming exercise ameliorates mood disorder and memory impairment by enhancing neurogenesis and serotonin expression and inhibiting apoptosis in social isolation.

Treadmill exercise ameliorates social isolation-induced memory impairment by enhancing silent information regulator-1 expression in rats

“…Compared to the rats that received 2 per cage, isolated rats had a significantly reduced BDNF concentration in the hippocampus, while no change was observed in other brain regions examined such as prefrontal cortex and striatum (Scaccianoce et al, 2006). BDNF and TrkB expression in the hippocampus was suppressed in the social isolation rats (Park et al, 2020). In this study, hippocampal BDNF and TrkB expression were decreased in the rats of the social isolation group compared to the control rats.…”

“…Social isolation and chronic unpredictable mild stress showed depressive behavior and exhibited mixed apoptosis/autophagy characteristics (Wang et al, 2019). Social isolation rats during adolescence showed increased in Bax expression and decreased in Bcl-2 expression compared to the group-housed rats (Park et al, 2020). In this study, Bax expression was increased, Bcl-2 expression was decreased, and cleaved caspase-3 expression in the hippocampus was increased in the rats of the social isolation group compared to the control rats.…”

“…Rodents have been widely used to assess developmental change in the fear and stress-related behaviors, and can exhibit a number of behavioral changes including anxiety response, decreased cognitive function, decreased motor activity, and aggressive behavior (Hefner and Holmes, 2007). During adolescence, the rats in the social isolation showed anxiety, depression, and short-term memory impairment, while swimming exercise relieved anxiety, depression, and short-term disability (Park et al, 2020).…”

Cognitive Consequences of Social Isolation During COVID-19: side effects and treatments

“…Regular treadmill exercise has improved isolation-induced depression-like behavior by regulating the hypothalamic-pituitary-adrenal (HPA) axis and this type of exercise has decreased stress hormones. Additionally, increased BDNF, NGF, serotonergic cells, and brain plasticity in the hippocampus have occurred after physical activity (22,106).…”

“…There is a connection between SI, learning, and memory impairments as well. Some studies have reported that environmental factors play a significant role in brain development and cognitive function in rodents, which directly affect learning and memory performance (22,23). Results suggest that SI as the lack of presence of others or the few numbers of meaningful relationships is vastly associated with many aspects of memory and learning impairment (24,25).…”