Davis J L, Pico R M
Brain Res. 1987 Mar 17;406(1-2):10-6. doi: 10.1016/0006-8993(87)90763-3.
In a single 10-s training trial, hatchling chicks were conditioned to suppress their spontaneous peck response to a small spherical target by coating it with an aversive liquid. A 24-h test trial employing a dry target demonstrated a robust memory for the training manifested in passive avoidance behavior. Leupeptin, a low-molecular-weight antiprotease, injected i.c.v. 1 h or 15 min prior to training attenuated the long-term avoidance response but not the initial training-induced peck suppression. Leupeptin had no effect on memory if given posttraining. A dose response experiment revealed that a 100- or 200-micrograms dose of leupeptin reliably impaired conditioned avoidance, whereas a 25 or 50-micrograms dose was ineffective. A dipeptide leupeptin analog (L-leucyl-L-arginine) possessed one-half the potency of the tripeptide in the memory task, and a different protease inhibitor (aprotinin) failed to effect the conditioned avoidance behavior. The mechanisms by which leupeptin may exert its influence in this behavioral paradigm and others are discussed.
在一次10秒的训练试验中，通过给幼雏小鸡的一个小的球形目标物涂上厌恶液体，使其条件性地抑制对该目标物的自发啄食反应。在一次24小时的测试试验中，使用干燥目标物，结果显示出在被动回避行为中表现出对训练的强大记忆。亮抑蛋白酶肽，一种低分子量抗蛋白酶，在训练前1小时或15分钟脑室内注射，可减弱长期回避反应，但不影响最初训练诱导的啄食抑制。如果在训练后给予亮抑蛋白酶肽，则对记忆没有影响。剂量反应实验表明，100微克或200微克剂量的亮抑蛋白酶肽能可靠地损害条件性回避，而25微克或50微克剂量则无效。一种二肽亮抑蛋白酶肽类似物（L-亮氨酰-L-精氨酸）在记忆任务中的效力是三肽的一半，而另一种蛋白酶抑制剂（抑肽酶）对条件性回避行为没有影响。本文讨论了亮抑蛋白酶肽可能在这种行为范式及其他范式中发挥作用的机制。
