Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Brain Behav Immun. 2011 Nov;25(8):1607-16. doi: 10.1016/j.bbi.2011.05.008. Epub 2011 May 24.
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 1000 μg 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)-1β and IL-6, at 3 and 18 h after injections. FSL-1 administration induced a dose-dependent fever (∼1°C) for two days, lethargy (∼78%) for four days, anorexia (∼65%) for three days and body mass stunting (∼6%) for at least four days. Eighteen hours after FSL-1 administration, when concentrations of IL-1β, 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.
为了研究学习和记忆的潜在后果，我们通过给大鼠注射成纤维细胞刺激脂肽-1（FSL-1）模拟了支原体感染的影响，FSL-1 是支原体唾液的发热成分。我们测量了体温、笼内活动、食物摄入以及在 Morris 水迷宫中的空间学习和记忆的影响。雄性 Sprague-Dawley 大鼠植入无线电转发器以测量腹部温度和笼内活动。恢复后，大鼠被随机分配接受腹腔内（I.P.）注射 FSL-1（500 或 1000μgkg-1 在 1mlkg-1 磷酸盐缓冲盐水；PBS）或载体（PBS，1mlkg-1）。每天测量体重和食物摄入量。注射后 18 小时开始在迷宫中进行训练，并连续进行四天。第五天评估空间记忆。在其他大鼠中，我们在注射后 3 小时和 18 小时测量了脑促炎细胞因子白细胞介素（IL）-1β和 IL-6 的浓度。FSL-1 给药导致两天的剂量依赖性发热（约 1°C）、四天的昏睡（约 78%）、三天的厌食（约 65%）和至少四天的体重停滞（约 6%）。FSL-1 给药后 18 小时，当下丘脑和海马体中的 IL-1β浓度升高，而大鼠发热、昏睡和厌食时，在迷宫中的学习没有受到影响。也没有记忆障碍。我们的结果支持这样的证据，即在模拟感染期间，学习和记忆受损并非不可避免。
