Effect of enriched environment on the pain threshold and depressive behavior in mice with chronic constriction injury / 临床麻醉学杂志

ABSTRACT

Objective To observe the effect of enriched environment (EE) on the pain threshold and depression like behavior in mice with chronic constriction injury (CCI) and the underly ing mechanism.Methods Sixty C57/BL6 mice were equally randomized into five groups:sham operation group (group Sham),CCI+standard environment(SE) group (group CS),CCI+EE group (group CE),CCI+EE+temozolomide group (group CET),CCI+EE+lipopolysaccharide group (group CEL).The paw withdraw threshold (PWT),paw withdraw latency,forced swim test (FST)and sucrose preference test (SPT) were evaluated,after the operation,meanwhile the hippocampal bromodeoxyuridine (Brdu),ki67 and doublecortin (ICX) positive cells,tumor necrosis factor-α (TNF-α) and interleukin-1β(IL-1β) were determined.Results Compared with group Sham,the PWT,PWL,sucrose consumption and Brdu,Ki67,DCX positive cells were significantly decreased,the immobility time and levels of TNF-α and IL-1β were obviously increased in group CS (P＜0.05).Compared with group CE,the PWT,PWL,sucrose consumption and Brdu,Ki67,DCX positive cells were significantly decreased in groups CS and CEL.The immobility time was obviously increased in groups CS,CET and CEL,moreover,the levels of TNF-α and IL-1β were significantly increased in groups CS and CEL (P＜0.05).Conclusion EE can improve the neuropathic pain,depression-like behavior and neural regeneration in mice with CCI.The inhibition of neural regeneration can block EE-induced improvement of depression-like behavior,but does not affect the pain threshold in mice with CCI.The augmentation of central inflammation can attenuate EE-induced improvement of pain threshold and depression-like behavior in mice with CCI.