Accurate discrimination between safe and dangerous stimuli is essential for survival. Prior research has begun to uncover the neural structures that are necessary for learning this discrimination, but exploration of brain regions involved in this learning process has been mostly limited to males. Recent findings show sex differences in discrimination learning, with reduced fear expression to safe cues in females compared to males. Here, we used male and female Sprague Dawley rats to explore neural activation, as measured by Fos expression, in fear and safety learning related brain regions. Neural activation after fear discrimination (Discrimination) was compared between males and females, as well as with fear conditioned (Fear Only) and stimulus presented (Control) conditions. Correlations of discrimination ability and neural activation were also calculated. We uncovered a correlation between central amygdala (CeA) activation and discrimination abilities in males and females. Anterior medial bed nucleus of the stria terminalis (BNST) was the only region where sex differences in Fos counts were observed in the Discrimination condition, and the only region where neural activation significantly differed between Fear Only and Discrimination conditions. Together, these findings indicate the importance of fear expression circuitry in mediating discrimination responses and generate important questions for future investigation.

准确区分安全刺激和危险刺激对于生存至关重要。先前的研究已经开始揭示学习这种辨别力所必需的神经结构，但对这种学习过程中涉及的大脑区域的探索主要仅限于男性。最近的研究结果表明，在歧视学习中存在性别差异，与男性相比，女性对安全线索的恐惧表达减少。在这里，我们使用雄性和雌性 Sprague Dawley 大鼠来探索恐惧和安全学习相关大脑区域的神经激活，如通过 Fos 表达测量的。在男性和女性之间以及恐惧条件（Fear Only）和刺激呈现（Control）条件下比较恐惧歧视（Discrimination）后的神经激活。还计算了辨别能力和神经激活的相关性。我们发现了中央杏仁核 (CeA) 激活与男性和女性的辨别能力之间的相关性。终纹前内侧床核 (BNST) 是唯一一个在歧视条件下观察到 Fos 计数性别差异的区域，也是唯一一个在恐惧和歧视条件下神经激活显着不同的区域。总之，这些发现表明恐惧表达回路在介导歧视反应中的重要性，并为未来的调查提出了重要的问题。终纹前内侧床核 (BNST) 是唯一一个在歧视条件下观察到 Fos 计数性别差异的区域，也是唯一一个在恐惧和歧视条件下神经激活显着不同的区域。总之，这些发现表明恐惧表达回路在介导歧视反应中的重要性，并为未来的调查提出了重要的问题。终纹前内侧床核 (BNST) 是唯一一个在歧视条件下观察到 Fos 计数性别差异的区域，也是唯一一个在恐惧和歧视条件下神经激活显着不同的区域。总之，这些发现表明恐惧表达回路在介导歧视反应中的重要性，并为未来的调查提出了重要的问题。