Saraco M G, Maldonado H
Facultad de Ciencias Exactas y Naturales, Depto de Biología, Buenos Aires University, Argentina.
Pharmacol Biochem Behav. 1995 Jun-Jul;51(2-3):223-9. doi: 10.1016/0091-3057(94)00325-d.
A shadow moving overhead acts as a danger stimulus and elicits an escape response in the crab Chasmagnathus granulatus that habituates promptly and for a long period. The effect of acute ethanol treatment on this long-term memory was analyzed. A single injection of 0.01, 0.05, or 0.1 micrograms ethanol (ET)/g given 30 min before iterated presentation of a visual danger stimulus failed to affect short-term habituation. Posttraining ethanol (0.01 to 0.1 microgram/g) produces a dose-dependent impairment of long-term habituation, but pretraining ethanol had no amnestic effect. However, a retention deficit confined to context memory was disclosed with both pre- and posttraining ethanol. Results from experiments with double injection (posttraining and pretesting injections) account for the retention impairment in terms of true amnesia (failure to acquire memory) but not due to state-dependence or retrieval deficit. The nonamnestic effect of pretraining ethanol upon long-term habituation is explained by a nonespecific depressing effect caused by interaction between iterative presentation of the danger stimulus and drug-induced internal state during training.
头顶上方移动的阴影作为一种危险刺激，会引发颗粒招潮蟹的逃避反应，且这种反应会迅速且长时间地产生习惯化。分析了急性乙醇处理对这种长期记忆的影响。在反复呈现视觉危险刺激前30分钟，单次注射0.01、0.05或0.1微克乙醇（ET）/克，并未影响短期习惯化。训练后注射乙醇（0.01至0.1微克/克）会导致长期习惯化出现剂量依赖性损伤，但训练前注射乙醇没有遗忘效应。然而，训练前和训练后注射乙醇均显示出仅限于情境记忆的记忆保持缺陷。两次注射（训练后和测试前注射）实验的结果表明，记忆保持损伤是由于真正的遗忘（未能形成记忆），而非状态依赖性或检索缺陷。训练前注射乙醇对长期习惯化的非遗忘效应，是由训练期间危险刺激的反复呈现与药物诱导的内部状态之间的相互作用所导致的非特异性抑制作用来解释的。
