Yavas Ersin, Fanselow Michael S
Department of Psychology, Bartın University, Bartın, Turkey.
Staglin Center for Brain and Behavioral Health, Department of Psychology, UCLA, Los Angeles, California, USA.
Integr Zool. 2025 Mar;20(2):394-406. doi: 10.1111/1749-4877.12892. Epub 2024 Sep 1.
Pavlovian fear conditioning serves as a valuable method for investigating species-specific defensive reactions (SSDRs) such as freezing and flight responses. The present study examines the role of white noise under different experimental conditions. Given that white noise has been shown to elicit both conditional (associative) and unconditional (nonassociative) defensive responses, we compared the response to noise following three separate training conditions: shock-only, white noise paired with shock, and context-only. Results showed that baseline freezing level significantly changed across groups: Both the shock-only group and the white noise paired with shock group froze more than the context-only group on the test day. White noise evoked differential freezing between groups on day 2: The shock-only group froze more than the context-only group although both groups were never exposed to white noise during training. Further, an activity burst triggered by white noise was similar for the shock-only and white noise paired with shock groups during testing, although shock-only group was never exposed to white noise stimuli during training. This aligned with c-fos data, indicating similar c-fos activity levels across different periaqueductal gray (PAG) regions for both shock-only and white noise paired with shock groups. However, the driving force behind c-fos activation-whether freezing, activity burst, or a combination of both-remains uncertain, warranting further analysis to explore specific correlations between SSDRs and c-fos activity within the PAG and related brain areas.
巴甫洛夫式恐惧条件反射是研究特定物种防御反应（SSDRs）（如僵住和逃跑反应）的一种有价值的方法。本研究考察了在不同实验条件下白噪声的作用。鉴于白噪声已被证明能引发条件性（联想性）和无条件性（非联想性）防御反应，我们比较了在三种不同训练条件后对噪声的反应：仅电击、白噪声与电击配对、仅情境。结果显示，各实验组的基线僵住水平有显著变化：在测试当天，仅电击组和白噪声与电击配对组的僵住程度均高于仅情境组。在第2天，白噪声在各实验组中引发了不同的僵住反应：仅电击组的僵住程度高于仅情境组，尽管两组在训练期间都从未接触过白噪声。此外，在测试期间，白噪声引发的活动爆发在仅电击组和白噪声与电击配对组中相似，尽管仅电击组在训练期间从未接触过白噪声刺激。这与c-fos数据一致，表明仅电击组和白噪声与电击配对组在不同的导水管周围灰质（PAG）区域的c-fos活动水平相似。然而，c-fos激活背后的驱动力——无论是僵住、活动爆发，还是两者的结合——仍不确定，需要进一步分析以探索PAG及相关脑区内SSDRs与c-fos活动之间的具体相关性。
