| dc.description.abstract | We assessed the antidepressant-like effects of environmental enrichment (EE) and
physical exercise (PE) compared with the selective serotonin reuptake inhibitor
fluoxetine against the depression-related neurobehavioral alterations induced by
postweaning social isolation (SI) in rats. After 1 month of SI, rats were submitted to PE
(treadmill), EE, or fluoxetine (10 mg/kg), which were compared with naïve SI and grouphoused
rats. After 1 month, behavior was analyzed in the open field (OFT), the sucrose
preference (SPT), and the forced swimming (FST) tests. Afterward, the hippocampal
serotonin contents, its metabolite, and turnover were measured. SI induced a depressionrelated
phenotype characterized by a marginal bodyweight gain, anxiety, anhedonia,
behavioral despair, and alterations of serotonin metabolism. EE produced the widest and
largest antidepressive-like effect, followed by PE and fluoxetine, which were almost
equivalent. The treatments, however, affected differentially the neurobehavioral domains
investigated. EE exerted its largest effect on anhedonia and was the only treatment
inducing anxiolytic-like effects. Fluoxetine, in contrast, produced its largest effect on
serotonin metabolism, followed by its anti-behavioral despair action. PE was a middleground
treatment with broader behavioral outcomes than fluoxetine, but ineffective to
reverse the serotonergic alterations induced by SI. The most responsive test to the
treatments was the FST, followed closely by the SPT. Although OFT locomotion and body
weight varied considerably between groups, they were barely responsive to PE and
fluoxetine. From a translational standpoint, our data suggest that exercise and recreational
activities may have broader health benefits than antidepressants to overcome
confinement and the consequences of chronic stress. | |
