Neuroscience Graduate Program, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA.
Department of Psychology, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA.
Cereb Cortex. 2024 Aug 1;34(8). doi: 10.1093/cercor/bhae328.
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.
新任务通常是分阶段学习的,每个阶段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,大多数关于目标导向学习的啮齿动物神经相关性研究都集中在单个结果测量和单个脑区上。在这里,我们从新手到专家在一个头部固定的操作性条件反射胡须辨别任务中,对老鼠进行了纵向研究。除了跟踪刺激辨别这一主要行为结果外,我们还跟踪和比较了一系列基于对象和基于时间的行为测量。这些行为分析在这个任务中确定了多个部分重叠的学习阶段,与初始反应实施、早期刺激-反应泛化和晚期反应抑制一致。为了开始理解这些学习过程的神经基础,我们在学习过程中对背侧新皮层进行了宽场 Ca2+成像,并将行为测量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测量之间存在明显且广泛的相关性。例如,感觉辨别能力的提高与目标刺激诱发的反应相关皮质的激活以及分心刺激诱发的全局皮质抑制有关。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,并为这些不同学习过程的神经元调节产生了假设。