title: The effect of surgical and psychological stress on learning and memory function in aged C57BL/6 mice.
abstract: Postoperative cognitive dysfunction (POCD) is an important complication following major surgery and general anesthesia in older patients. However, the etiology of POCD remains largely to be determined. It is unknown how surgical stress and psychological stress affect the postoperative learning and memory function in geriatric patients. We therefore established a pre-clinical model in aged C57BL/6 mice and aimed to investigate the effects of surgical stress and psychological stress on learning and memory function and the possible roles of the protein kinase B/mammalian target of rapamycin (AKT/mTOR) pathway. The surgical stress was induced by abdominal surgery under local anesthesia, and the psychological stress was induced by a communication box. Cognitive functions and markers of the AKT/mTOR pathway were assessed at 1, 3 and 7 days following the stress. The impairments of learning and memory function existed for up to 7 days following surgical stress and surgical stress plus psychological stress, whereas the psychological stress did not affect the cognitive function alone or combined with surgical stress. Analysis of brain tissue revealed a significant involvement of the AKT/mTOR pathway in the impairment of cognition. These data suggested that surgical stress could induce cognitive impairment in aged mice and perioperative psychological stress is not a constitutive factor of POCD. The AKT/mTOR pathway is likely involved as one of the underlying mechanisms of the development of POCD.
authors.affiliation: Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: C
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Ultrasound, The Southern Building, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: C
authors.initials: C
authors.lastname: Li
authors.affiliation: Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: S
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing 100853, China; Department of Anesthesiology, Navy General Hospital, Beijing 100048, China.
authors.forename: P
authors.initials: P
authors.lastname: Li
authors.affiliation: Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: J
authors.initials: J
authors.lastname: Cao
authors.affiliation: Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing 100853, China. Electronic address: plamzk@126.com.
authors.forename: W
authors.initials: W
authors.lastname: Mi
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015151:Immunoblotting; D007858:Learning; D008568:Memory; D051379:Mice; D008810:Mice, Inbred C57BL; D011183:Postoperative Complications / Q000523:psychology*; D013315:Stress, Psychological / Q000150:complications*; D013514:Surgical Procedures, Operative / Q000523:psychology*
keywords: AKT/mTOR signaling pathway; learning; memory; postoperative cognitive dysfunction; psychological stress; surgical procedures