Dissociation between learning and memory impairment and other sickness behaviours during simulated Mycoplasma infection in rats

作者：Swanepoel Tanya^*; Harvey Brian H; Harden Lois M; Laburn Helen P; Mitchell Duncan

来源：Brain, Behavior, and Immunity, 2011, 25(8): 1607-1616.

DOI：10.1016/j.bbi.2011.05.008

• Rat
• Systemic infection
• Learning and memory
• Morris Water Maze
• Interleukin (IL)-1 beta
• IL-6
• Hippocampus
• Hypothalamus
• Fibroblast-stimulating lipopeptide-1

To investigate potential consequences for learning and memory, we have simulated the effects of Mycoplasma infection, in rats, by administering fibroblast-stimulating lipopepide-1 (FSL-1), a pyrogenic moiety of Mycoplasma salivarium. We measured the effects on body temperature, cage activity, food intake, and on spatial learning and memory in a Morris Water Maze. Male Sprague-Dawley rats had radio transponders implanted to measure abdominal temperature and cage activity. After recovery, rats were assigned randomly to receive intraperitoneal (I.P.) injections of FSL-1 (500 or 10001 mu g kg(-1) in 1 ml kg(-1) phosphate-buffered saline; PBS) or vehicle (PBS, 1 ml kg(-1)). Body mass and food intake were measured daily. Training in the Maze commenced 18 h after injections and continued daily for four days. Spatial memory was assessed on the fifth day. In other rats, we measured concentrations of brain pro-inflammatory cytokines, interleukin (IL)-1 beta and IL-6, at 3 and 18 h after injections. FSL-1 administration induced a dose-dependent fever (similar to 1 degrees C) for two days, lethargy (similar to 78%) for four days, anorexia (similar to 65%) for three days and body mass stunting (similar to 6%) for at least four days. Eighteen hours after FSL-1 administration, when concentrations of IL-1 beta, but not that of IL-6, were elevated in both the hypothalamus and the hippocampus, and when rats were febrile, lethargic and anorexic, learning in the Maze was unaffected. There also was no memory impairment. Our results support emerging evidence that impaired learning and memory is not inevitable during simulated infection.

• 出版日期2011-11
• 单位西北大学