Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu 30013, Taiwan.
Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu 30013, Taiwan; Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan.
Neurobiol Learn Mem. 2023 Oct;204:107800. doi: 10.1016/j.nlm.2023.107800. Epub 2023 Jul 29.
Hyperactive orbitofrontal cortical activation is commonly seen in patients of obsessive-compulsive disorder (OCD). Previous studies from our laboratory showed that for rats with aberrant activation of the orbitofrontal cortex (OFC) during the extinction phase, they were unable to use contexts as the reference for proper retrieval of fear memory during renewal test. This result supported the phenomenon that many OCD patients show poor regulation of fear-related behavior. Since there are robust anatomical connections of the OFC with the fear-circuit, we aim to further examine whether the OFC is actively engaged in fear regulation under normal circumstances. In this study, the lateral or medial OFC was inactivated during the extinction phase using the ABA fear renewal procedure. We found that these animals showed intact fear renewal during retrieval test with their freezing levels equivalent to the control rats, revealing that the OFC did not have decisive roles in extinction acquisition. Together with our previous study, we suggest that the OFC only interferes with fear regulation when it becomes pathophysiologically hyperactive.
眶额皮层过度活跃在强迫症（OCD）患者中很常见。我们实验室之前的研究表明，对于眶额皮层（OFC）在消退阶段异常活跃的大鼠，它们无法在更新测试中使用环境作为正确检索恐惧记忆的参考。这一结果支持了许多 OCD 患者表现出对恐惧相关行为的调节不良的现象。由于 OFC 与恐惧回路之间存在强大的解剖连接，我们旨在进一步研究在正常情况下 OFC 是否积极参与恐惧调节。在这项研究中，使用 ABA 恐惧更新程序在消退阶段使外侧或内侧 OFC 失活。我们发现，这些动物在检索测试中表现出完整的恐惧更新，其冻结水平与对照大鼠相当，表明 OFC 在消退获得中没有决定性作用。结合我们之前的研究，我们认为只有当眶额皮层变得病理生理学上过度活跃时，它才会干扰恐惧调节。
