Phasic signaling in the bed nucleus of the stria terminalis during fear learning predicts within- and across-session cued fear expression
Phasic signaling in the bed nucleus of the stria terminalis during fear learning predicts within- and across-session cued fear expression
复制标题
DOI：
10.1101/lm.050807.119
复制
发表时间：
2020-03-01
影响因子：
2
通讯作者：
Halladay, Lindsay R.
中科院分区：
文献类型：
--
作者：
Bjorni, Max;Rovero, Natalie G.;Halladay, Lindsay R.
虽然许多过去的研究结果表明终纹床核（BNST）介导持续负面情绪的表达，但最近的研究强调了BNST更复杂的作用，除了防御反应外，还包括恐惧学习。由于BNST被认为是编码模糊或不可预测的威胁，它似乎是合理的，它可能参与编码早期线索的恐惧学习，特别是紧接着第一个音调-电击配对时，条件刺激-非条件刺激（CS-US）的偶然性是不完全明显的。为了研究这一点，我们进行了在体电生理记录研究，以检查神经动力学的BNST单位在线索恐惧收购和回忆。我们确定了两个功能不同的BNST神经元亚群，编码的审讯间隔（ITI），并可能有助于内和跨会话恐惧学习。"斜坡"细胞活动在线索恐惧收购平行增加冻结表达的小鼠学习CS-US应急，而"相位"细胞编码休克后（USpost）时期（30秒后，遇到脚休克），只有在早期试验。重要的是，相位单位响应的幅度第一USpost期间预测不仅冻结表达响应随后的CS在收购过程中，但CS冻结诱发24小时后在CS检索。这些发现首次表明，BNST活动可能作为一个有益的信号在线索恐惧学习。
While results from many past studies have implicated the bed nucleus of the stria terminalis (BNST) in mediating the expression of sustained negative affect, recent studies have highlighted a more complex role for BNST that includes aspects of fear learning in addition to defensive responding. As BNST is thought to encode ambiguous or unpredictable threat, it seems plausible that it may be involved in encoding early cued fear learning, especially immediately following a first tone-shock pairing when the conditioned stimulus-unconditioned stimulus (CS-US) contingency is not fully apparent. To investigate this, we conducted in vivo electrophysiological recording studies to examine neural dynamics of BNST units during cued fear acquisition and recall. We identified two functionally distinct subpopulations of BNST neurons that encode the intertrial interval (ITI) and may contribute to within- and across-session fear learning. "Ramping" cell activity during cued fear acquisition parallels the increase in freezing expression as mice learn the CS-US contingency, while "Phasic" cells encode postshock (USpost) periods (30 sec following encounter with footshock) only during early trials. Importantly, the magnitude of Phasic unit responsivity to the first USpost period predicted not only freezing expression in response to the subsequent CS during acquisition, but also CS freezing evoked 24 h later during CS retrieval. These findings suggest for the first time that BNST activity may serve as an instructive signal during cued fear learning.