Hikind Noam, Maroun Mouna
Department of Neurobiology and Ethology, Faculty of Science and Science Education, University of Haifa, Mount Carmel, Haifa, Israel.
Neurobiol Learn Mem. 2008 Jul;90(1):217-22. doi: 10.1016/j.nlm.2008.03.003. Epub 2008 Apr 28.
In auditory fear conditioning, repeated presentation of the tone in the absence of the shock leads to extinction of the acquired fear response. Both the medial prefrontal cortex (mPFC) and the basolateral amygdala (BLA) are involved in extinction. Here we examined this involvement by antagonizing D1 receptors in both regions, in the rat. We microinfused the D1 receptor antagonist, SCH23390, into the infra-limbic part of the mPFC (IL) or BLA at different time points. SCH23390 mircoinfused into the IL either before extinction acquisition or following short extinction training resulted in impairment of extinction consolidation. Microinfusion of SCH23390 into the BLA, prior to acquisition of extinction caused impairment in acquisition of extinction without affecting extinction consolidation. This is supported by the results showing that microinfusion of SCH23390 into the BLA following a short-training session did not affect consolidation. These results further strengthen the role of mPFC in consolidation of extinction while highlighting the role of the D1 receptors in this process.
在听觉恐惧条件反射中，在无电击的情况下重复呈现音调会导致习得的恐惧反应消退。内侧前额叶皮质（mPFC）和基底外侧杏仁核（BLA）均参与消退过程。在此，我们通过拮抗大鼠这两个区域中的D1受体来研究这种参与情况。我们在不同时间点将D1受体拮抗剂SCH23390微量注入mPFC的下缘脑区（IL）或BLA。在消退习得之前或经过短暂的消退训练后将SCH23390微量注入IL会导致消退巩固受损。在消退习得之前将SCH23390微量注入BLA会导致消退习得受损，但不影响消退巩固。这一结果得到了以下结果的支持，即在短暂训练后将SCH23390微量注入BLA并不影响巩固。这些结果进一步强化了mPFC在消退巩固中的作用，同时突出了D1受体在此过程中的作用。
