Orbitofrontal cortical circuitry mediating post-decision confidence reports

你对你刚刚做出的决定有多大的信心？我们可以很容易地回答这个问题，估计我们所做的选择是正确的。在这里，我建议通过将大鼠的心理物理工具与新的光遗传学技术相结合，来研究这种信心报告的神经基础，从而允许记录和操纵大脑中已识别的神经回路的活动。在心理物理实验中，大鼠通过进入一个选择通道来学习对感觉刺激的身份做出选择，在这个选择通道中，它们必须等待延迟的奖励。老鼠通过在离开选择口岸之前愿意等待奖励的时间来表达他们对选择的信心，提供了决策后的信心报告。以前的研究表明，额叶皮质的一个亚区--眶前皮质(OFC)参与了大鼠信心报告的调节。然而，目前尚不清楚OFC中存在的不同细胞类型如何形成潜在的自信引导行为的神经回路。我的目标是用三个步骤来确定这个电路。首先，我将通过使用病毒示踪剂将OFC的投射映射到皮质下区域来识别OFC中的投射细胞类型。其次，我将电记录OFC中已识别细胞类型的单个神经元的活动，以确定它们在决策后置信度报告中携带的信息。在电生理记录过程中，通过光学激活特定细胞类型中的光敏通道，将使用光遗传学方法识别神经元。最后，使用同样的光遗传学方法，我将使用光刺激或光抑制来干扰OFC细胞类型的活动，以评估OFC细胞类型在驱动自信引导决策中的因果贡献。我希望这项提议将揭示大鼠决策信心的回路，并通过确定不同细胞类型的行为相关性，为解决在额叶皮质观察到的神经反应的多样性做出贡献。

How confident are you in the decision you just took? We are readily able to answer this question, providing an estimate of our certainty that the choice we made was correct. Here I propose to study the neural underpinnings of such confidence reports by combining psychophysical tools in rats with novel optogenetic techniques allowing for recording and manipulating the activity of identified neural circuits in the brain. In psychophysical experiments, rats learn to make a choice about the identity of a sensory stimulus by entering a choice port, in which they have to wait for a delayed reward. Rats express their confidence in the choice by the amount of time they are willing to wait for a reward before leaving the choice port, providing a post-decision confidence report. Previous work has implicated the orbitofrontal cortex (OFC), a sub region of frontal cortex, in mediating confidence reports in rats. However, it is unknown how different cell types present in OFC form the neural circuitry underlying confidence-guided behaviors. I aim to determine this circuitry in three steps. First I will identify the projection cell types in OFC by mapping the projections from OFC to subcortical areas using viral tracers. Second I will electrically record the activity of single neurons from identified cell types in OFC to determine the information they carry during post-decision confidence reports. Neurons will be identified using optogenetic methods by optically activating light-sensitive channels in defined cell types during electrophysiological recordings. Finally, using the same optogenetic approach, I will perturb the activity of OFC cell types using optical stimulation or inhibition to assess the causal contribution of OFC cell types in driving confidence-guided decisions. I expect that this proposal will uncover the circuitry mediating decision confidence in rats and contribute in resolving the diversity of neural responses observed in frontal cortex by determining the behavioral correlates of distinct cell types.