Paschall Gayla Y, Davis Michael
Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
Learn Mem. 2002 Nov-Dec;9(6):395-401. doi: 10.1101/lm.50602.
Recently, we reported that discrete (4-sec) olfactory cues paired with footshock serve as effective conditioned stimuli (CSs) for potentiating the acoustic startle response in rats using the fear-potentiated startle paradigm. Because odors are such salient cues for the rat, and because of the robust olfactory conditioning observed previously, the current studies investigated second-order fear conditioning using olfactory and visual cues. In Experiments 1 and 2, we used a small number of first-order and second-order training trials on separate days to investigate second-order fear-potentiated startle. Significant potentiated startle was observed in animals receiving Paired/Paired training in both studies, but surprisingly, control animals in the Unpaired/Paired group (Exp. 1) also showed significant potentiated startle to a light S2 at testing. These findings are addressed in the Discussion. Overall, the results of both experiments suggest that olfactory cues serve as efficient S1 and S2 stimuli in second-order fear-potentiated startle paradigms when only a small number of first and second-order training trials are presented.
最近，我们报道了在使用恐惧增强惊吓范式时，与足部电击配对的离散（4秒）嗅觉线索可作为有效的条件刺激（CSs），用于增强大鼠的听觉惊吓反应。由于气味对大鼠来说是如此显著的线索，并且鉴于之前观察到的强大的嗅觉条件作用，当前的研究使用嗅觉和视觉线索研究了二级恐惧条件作用。在实验1和实验2中，我们在不同的日子里进行了少量的一级和二级训练试验，以研究二级恐惧增强惊吓。在两项研究中，接受配对/配对训练的动物都观察到了显著的增强惊吓，但令人惊讶的是，未配对/配对组（实验1）中的对照动物在测试时对光S2也表现出显著的增强惊吓。这些发现将在讨论中阐述。总体而言，两个实验的结果表明，当只进行少量的一级和二级训练试验时，嗅觉线索在二级恐惧增强惊吓范式中可作为有效的S1和S2刺激。
