Winston C R, Leavell B J, Ardayfio P A, Beard C, Commissaris R L
Department of Pharmaceutical Sciences, College of Pharmacy and AHP, Wayne State University, Detroit, MI 48202, USA.
Physiol Behav. 2001 May;73(1-2):9-17. doi: 10.1016/s0031-9384(01)00443-7.
In the Fear-Potentiated Startle (FPS) paradigm, the reflexive response to a noise burst is enhanced when it is presented with a stimulus (typically a light) that previously had been paired with the presentation of an aversive stimulus, usually an electric shock. In the FPS paradigm, the conditioned effect is demonstrated under conditions of extinction, i.e., the light is not paired with the shock during FPS testing. Because of this, the FPS paradigm is of somewhat limited value as a longitudinal measure for studying classically conditioned enhancement of acoustic startle. The present studies report a simple and reliable nonshock procedure for studying classically conditioned potentiation of acoustic startle in the rat that does not utilize testing under conditions of extinction. Naive rats were exposed to 5-or 3-days/week startle test sessions for up to 20 weeks. Twenty (20) startle stimuli (115 dB noise bursts; 40 ms in duration) were presented during each session. Half of these startle stimuli were presented in darkness and half were immediately preceded by a 3500-ms presentation of a 15-W light. With this paradigm, the effects of pairing the light with the startle noise burst could be studied across many test sessions in the absence of extinction training. The light did not increase startle amplitude on the first few startle trials of the first test session. By the end of the first session, however, and continuing for many weeks of testing, startle responses in the presence of the light were significantly greater (by 30-40%) than in the absence of the light. The finding that the startle stimulus itself can serve as an unconditioned stimulus (UCS) to enhance subsequent startle responses replicates an earlier finding. The persistence of this Startle-Potentiated Startle (SPS) effect across multiple weeks of testing is in contrast to that earlier report.
在恐惧增强惊吓（FPS）范式中，当一个噪声猝发与先前曾与厌恶刺激（通常是电击）呈现配对的刺激（通常是光）同时呈现时，对该噪声猝发的反射性反应会增强。在FPS范式中，条件作用效应在消退条件下得到证明，即光在FPS测试期间不与电击配对。因此，作为研究经典条件作用增强听觉惊吓的纵向测量方法，FPS范式的价值在一定程度上有限。本研究报告了一种简单可靠的非电击程序，用于研究大鼠经典条件作用增强听觉惊吓，该程序不采用在消退条件下的测试。未经过训练的大鼠每周接受5天或3天的惊吓测试，持续长达20周。每次测试期间呈现20次惊吓刺激（115分贝噪声猝发；持续时间40毫秒）。这些惊吓刺激中有一半在黑暗中呈现，另一半在呈现前3500毫秒有一个15瓦的光。采用这种范式，可以在没有消退训练的情况下，通过多次测试来研究光与惊吓噪声猝发配对的效果。在第一次测试的最初几次惊吓试验中，光并没有增加惊吓幅度。然而，到第一次测试结束时，并在持续数周的测试中，有光时的惊吓反应比无光时显著更大（增加30 - 40%）。惊吓刺激本身可以作为无条件刺激（UCS）来增强后续惊吓反应这一发现重复了早期的一项发现。与早期报告相比，这种惊吓增强惊吓（SPS）效应在数周测试中的持续性有所不同。
