The effects of an enriched environment on psychological and behavioral symptoms of senescence / 中华物理医学与康复杂志

ABSTRACT

Objective To investigate the effects of an enriched environment (EE) on the psychological and behavioral symptoms of senescence and on the level of plasmic adrenocorticotropic hormone (ACTH) and serum corticosteroid (Cor). MethodsTwenty male senescence-prone SAMP8 mice of 3 months old were divided randomly into an enriched environment (EE) group and a standard environment (SE) group.Five male senescence-resistant SAMR1 mice of the same age served as the control group.Behavioral symptoms were assessed after 2 months using autonomic activity and elevated-plus maze (EPM) test performance.Plasma ACTH and serum Cor were detected using radio-immunologic methods. ResultsAverage autonomic activity frequency and EPM open-arm times were significantly lower with the SAMP8 mice than among the control group,and the autonomic activity frequency was significantly higher in the EE group than in the SE group of SAMP8 mice.The average EPM open-arm times of the EE group and the SE were not significantly different.Average ACTH and Cor levels were both significantly lower in the SAMP8 mice,and the level of ACTH was significantly higher in the EE group than in the SE group.There was no significant difference in these groups' average Cor levels. ConclusionsThe SAMP8 mice of 5 months demonstrated significant mental and behavioral abnormalities,as well as down-regulated plasma levels of ACTH and Cor.EE An enhanced environment can reduce behavioral disturbance through up-regulating ACTH.