Aims: 

Several physiological functions, including stress hormone release are gender dependent. The aim of this study was to test the hypothesis that environmental enrichment used as a model of increased brain plasticity, induces gender-dependent effects on neuroendocrine activity in rats.

Methods: 

Wistar rats were housed under standard conditions or in big cages with repeated changing of environmental objects (3 times a week) for 6 weeks. Male and female rats were housed separately. Blood and tissues for hormone and/or brain derived neurotrophic factor (BDNF) analyses were samples following decapitation.

Results: 

Plasma corticosterone and the weight of adrenal glands were higher in female compared to male rats. Though corticosterone levels were not modified by housing in enriched environment, plasma ACTH increased significantly (p < 0.05) in male but not in female rats exposed to environmental enrichment. Oxytocin concentrations in plasma were higher in female than in male rats (p < 0.001). Oxytocin content in the posterior pituitary was not modified by any experimental condition. As expected, concentrations of BDNF in the hippocampus were significantly increased by exposure to enriched environment. Moreover, BDNF levels were higher in female than in male hippocampus and the influence of environmental enrichment was significantly more intensive in females than in males (p < 0.001).

Conclusion: 

Increase in neural plasticity as well as changes in neuroendocrine functions induced by housing the rats in enriched environment seem to be different in males and females. The study was supported by grants of APVV LPP-0194-0 and VEGA 5064.