PDF(Pubmed)
Abstract：
New tasks are often learned in stages with each stage reflecting a different learning challenge. Accordingly, each learning stage is likely mediated by distinct neuronal processes. And yet, most rodent studies of the neuronal correlates of goal-directed learning focus on individual outcome measures and individual brain regions. Here, we longitudinally studied mice from naïve to expert performance in a head-fixed, operant conditioning whisker discrimination task. In addition to tracking the primary behavioral outcome of stimulus discrimination, we tracked and compared an array of object-based and temporal-based behavioral measures. These behavioral analyses identify multiple, partially overlapping learning stages in this task, consistent with initial response implementation, early stimulus-response generalization, and late response inhibition. To begin to understand the neuronal foundations of these learning processes, we performed widefield Ca2+ imaging of dorsal neocortex throughout learning and correlated behavioral measures with neuronal activity. We found distinct and widespread correlations between neocortical activation patterns and various behavioral measures. For example, improvements in sensory discrimination correlated with target stimulus evoked activations of response-related cortices along with distractor stimulus evoked global cortical suppression. Our study reveals multidimensional learning for a simple goal-directed learning task and generates hypotheses for the neuronal modulations underlying these various learning processes.
摘要：
新任务通常是分阶段学习的，每个阶段都反映了不同的学习挑战。因此，每个学习阶段都可能由不同的神经元过程介导。然而，大多数啮齿动物对目标导向学习的神经元相关性的研究集中在个体结局指标和个体大脑区域。这里,我们纵向研究了小鼠从幼稚到专家的头部固定表现，操作调理晶须辨别任务。除了跟踪刺激歧视的主要行为结果，我们跟踪并比较了一系列基于对象和基于时间的行为度量。这些行为分析确定了多个，在这个任务中部分重叠的学习阶段，与初始响应实施一致，早期刺激-反应概括，和后期反应抑制。为了开始理解这些学习过程的神经元基础，我们在整个学习过程中对背侧新皮质进行了宽视野Ca2+成像,并将行为测量值与神经元活动相关联.我们发现新皮层激活模式与各种行为措施之间存在明显而广泛的相关性。例如,感觉辨别的改善与目标刺激引起的反应相关皮质的激活以及干扰刺激引起的整体皮质抑制相关。我们的研究揭示了一个简单的目标导向学习任务的多维学习，并为这些各种学习过程背后的神经元调制生成了假设。
