Blundell Jacqueline, Adamec Robert, Burton Paul
Department of Psychology, Memorial University, St. John's, NF, Canada.
Physiol Behav. 2005 Sep 15;86(1-2):233-43. doi: 10.1016/j.physbeh.2005.07.012.
Effects on behavioral response to predator stress of competitive block of NMDA receptors with doses of .1, 1.0 and 10 mg/kg of CPP (3-(2-carboxypiperazin4-yl)propyl-l-phosphonic acid) were studied. An affect test battery assessed behavioral response to stress and employed hole board, elevated plus maze, light/dark box, social interaction, social avoidance and response to acoustic startle tests. Doses of 1-10 mg/kg of CPP administered ip 30 min prior to predator stress blocked the effects of predator stress on some but not all behaviors measured 8-9 days later. Predator stress normally reduces open arm exploration and risk assessment in the plus maze, decreases entries into the lighted arm of the light dark box and delays habituation of the acoustic startle response. CPP blocked all of these effects of predator stress. A dose of 10 mg/kg of CPP was required for all behaviors except habituation to startle. Block of effects on habituation to startle occurred at 1 and 10 mg/kg. Behaviors in which effects of predator stress were not blocked by CPP included reduction in unprotected head dips in the elevated plus maze and reduced social interaction. In addition, predator stress was without effect on social avoidance measured with the Haller test. These findings extend previous work showing NMDA receptor dependence of effects of predator stress on behavior in the elevated plus maze and on amplitude of acoustic startle response. Novel findings include NMDA receptor dependence of predator stress effects on light dark box behavior and startle habituation. Taken together, the findings add to a body of evidence showing that a syndrome of behavioral changes follows predator stress. Components of this syndrome of behavioral changes likely depend on changes in separable neural substrates initiated in part by NMDA receptors as well as by other neurochemical means.
研究了分别给予剂量为0.1、1.0和10mg/kg的CPP（3-(2-羧基哌嗪-4-基)丙基-1-膦酸）竞争性阻断NMDA受体对捕食者应激行为反应的影响。采用一套行为测试组合来评估对应激的行为反应，包括使用洞板试验、高架十字迷宫试验、明暗箱试验、社交互动试验、社交回避试验以及对听觉惊吓试验的反应。在捕食者应激前30分钟腹腔注射1-10mg/kg的CPP剂量，可阻断捕食者应激对8-9天后所测量的部分而非全部行为的影响。捕食者应激通常会减少高架十字迷宫中的开放臂探索和风险评估，减少进入明暗箱亮臂的次数，并延迟听觉惊吓反应的习惯化。CPP可阻断捕食者应激的所有这些影响。除惊吓习惯化外，所有行为均需要10mg/kg的CPP剂量。对惊吓习惯化影响的阻断发生在1mg/kg和10mg/kg剂量时。CPP未阻断捕食者应激影响的行为包括高架十字迷宫中无保护头部下垂次数的减少和社交互动的减少。此外，捕食者应激对用哈勒试验测量的社交回避没有影响。这些发现扩展了先前的研究工作，表明捕食者应激对高架十字迷宫行为和听觉惊吓反应幅度的影响依赖于NMDA受体。新发现包括捕食者应激对明暗箱行为和惊吓习惯化的影响依赖于NMDA受体。综上所述，这些发现增加了一系列证据，表明捕食者应激后会出现行为变化综合征。这种行为变化综合征的组成部分可能部分取决于由NMDA受体以及其他神经化学途径引发的可分离神经基质的变化。
