Infralimbic cortex activity is required for the expression but not the acquisition of conditioned safety
Infralimbic cortex activity is required for the expression but not the acquisition of conditioned safety
复制标题
DOI：
10.1007/s00213-020-05527-7
复制
发表时间：
2020-05-04
影响因子：
3.4
通讯作者：
Fendt, Markus
中科院分区：
文献类型：
--
作者：
Kreutzmann, Judith C.;Jovanovic, Tanja;Fendt, Markus
区分危险和安全的能力对于跨物种的生存至关重要。危险信号预示着潜在威胁事件的发生，而安全信号则表明不发生令人厌恶的事件，从而减少恐惧和压力反应。虽然条件安全的神经基础仍有待阐明，恐惧消退研究提供的证据表明，边缘下皮层（IL）调节恐惧抑制。在本研究中，通过局部注射蝇蕈醇暂时灭活雄性和雌性大鼠中的IL。利用惊吓反应研究了IL失活对条件安全性获得和表达的影响。在调节前暂时灭活IL不影响获得条件安全性，而在表达试验期间IL灭活完全阻断雄性和雌性大鼠中条件安全性的表达。在表达测试过程中，邻近的边缘前叶（PL）皮层的失活并不影响安全记忆的表达。我们的研究结果表明，IL是表达安全记忆的关键脑区。由于患有焦虑症的患者通常无法利用安全提示来抑制恐惧，因此本研究结果具有临床相关性，并可能有助于焦虑相关精神疾病的治疗优化。
The ability to discriminate between danger and safety is crucial for survival across species. Whereas danger signals predict the onset of a potentially threatening event, safety signals indicate the non-occurrence of an aversive event, thereby reducing fear and stress responses. While the neural basis of conditioned safety remains to be elucidated, fear extinction studies provide evidence that the infralimbic cortex (IL) modulates fear inhibition. In the current study, the IL was temporarily inactivated with local muscimol injections in male and female rats. The effect of IL inactivation on the acquisition and expression of conditioned safety was investigated utilizing the startle response. Temporary inactivation of the IL prior to conditioning did not affect the acquisition of conditioned safety, whereas IL inactivation during the expression test completely blocked the expression of conditioned safety in male and female rats. Inactivation of the neighboring prelimbic (PL) cortex during the expression test did not affect the expression of safety memory. Our findings suggest that the IL is a critical brain region for the expression of safety memory. Because patients suffering from anxiety disorders are often unable to make use of safety cues to inhibit fear, the present findings are of clinical relevance and could potentially contribute to therapy optimization of anxiety-related psychiatric disorders.