Heldt Scott A, Falls William A
Department of Psychology, Northern Illinois University, DeKalb, IL, USA.
Behav Brain Res. 2003 Sep 15;144(1-2):175-85. doi: 10.1016/s0166-4328(03)00092-5.
The inferior colliculus (IC) is the major source of auditory information involved in processing the behavioral significance of acoustic stimuli. In the current study, we assessed whether the IC is a critical source of information which mediates the expression of fear and the inhibition of fear conditioned to an auditory stimulus. Fear and the inhibition of fear were tested by measuring fear-potentiated startle. In Experiment 1, we demonstrated that rats which received electrolytic lesions of the IC failed to show fear-potentiated startle in the presence of a noise previously conditioned to elicit fear. In Experiment 2, we demonstrated that rats with similarly placed lesions of the IC failed to inhibit fear-potentiated startle in the presence of a noise previously conditioned to inhibit fear to a light. Thus, in both Experiments 1 and 2, lesions of the IC disrupted the behavioral significance of the noise stimulus. Together with previous findings, these results are consistent with the view that the IC is a common source of diverging auditory information used to mediate the fear eliciting and safety signal properties conditioned to auditory stimuli.
下丘（IC）是参与处理声学刺激行为意义的主要听觉信息来源。在本研究中，我们评估了IC是否是介导恐惧表达以及对听觉刺激条件性恐惧抑制的关键信息源。通过测量恐惧增强惊吓反应来测试恐惧和恐惧抑制。在实验1中，我们证明接受IC电解损伤的大鼠在先前条件性引发恐惧的噪声存在时未能表现出恐惧增强惊吓反应。在实验2中，我们证明具有类似位置IC损伤的大鼠在先前条件性抑制对光的恐惧的噪声存在时未能抑制恐惧增强惊吓反应。因此，在实验1和实验2中，IC损伤均破坏了噪声刺激的行为意义。与先前的研究结果一起，这些结果与以下观点一致，即IC是用于介导对听觉刺激条件性引发恐惧和安全信号特性的发散听觉信息的共同来源。
