What are the neurobiological mechanisms mediating operant self-learning?

在操作性学习中，有两种进化上保守的机制，一种是主体学习环境中的因果关系（世界学习），另一种是主体学习自己行为的结果（自我学习）。调节世界学习的神经生物学机制已经被很好地理解了：它们在进化上是保守的，因此与许多其他学习实验（如经典条件反射）中的机制几乎相同。然而，我们对操作性自我学习的神经生物学知之甚少。在前一个资助期的成功结合分子生物学和行为实验，隔离的操作性自我学习组件的基础上，我们提出了一个类似的项目，以进一步阐明基因和神经元参与操作性自我学习。上一个资助期提供的结果表明，FoxP依赖的可塑性是不需要在大脑中，但在腹神经索的运动神经元，支配特定的直接翼转向肌肉。我们还发现，FoxP阳性神经元中需要非典型蛋白激酶C（aPKC）的基因产物。本资助期的一个核心研究问题将是确定FoxP/aPKC通路的更多组成部分，这些组成部分介导运动神经元的可塑性，而运动神经元是操作性自我学习的基础。为此，我们将使用两种分子技术，DamID和TurboID。通过DamID，我们将确定FoxP结合和调节的靶基因。通过TurboID，我们将鉴定aPKC相互作用的靶蛋白。这两种技术中最有前途的候选基因将被操纵和测试，用于操作性自我学习。除了这些分子技术，我们已经从文献中产生了一系列候选基因，以确定FoxP/aPKC以外的可塑性机制。最后，我们还将与北京的Liu教授合作，验证他筛选出的参与操作性活动的大脑神经元的候选人，这是一个导致自我学习的过程。Liu实验室已经在大脑中发现了操作性自我学习所需的神经元，无论它们是否表达FoxP。在我们的合作中，我们将独立复制该实验室的结果，北京的实验室将复制我们最有希望的候选品系实验。

In operant learning, two evolutionarily conserved mechanisms are engaged, one where the subject learns about causal relations in the environment (world-learning) and another where the subject learns about the outcomes of their own behavior (self-learning). The neurobiological mechanisms mediating world-learning are well understood: they are evolutionarily conserved and thus nearly identical to those in many other learning experiments such as classical conditioning. However, we know very little about the neurobiology of operant self-learning. Building on the previous funding period’s successful combination of molecular biology and a behavioral experiment that isolates the operant self-learning component, we propose an analogous project to further elucidate the genes and neurons involved in operant self-learning. The previous funding period provided results that suggest that FoxP-dependent plasticity is not required in the brain but in motor neurons in the ventral nerve cord that innervate specific direct wing steering muscles. We also discovered that the gene product of the atypical protein kinase C (aPKC) is required in FoxP-positive neurons. One core research question for this funding period will be to identify more components of the FoxP/aPKC pathway mediating the plasticity in motor neurons that underlies operant self-learning. To this end, we will use two molecular techniques, DamID and TurboID. With DamID we will identify the target genes that FoxP binds to and regulates. With TurboID, we will identify the target proteins that aPKC interacts with. The most promising candidate genes from these two techniques will be manipulated and tested for operant self-learning. In addition to these molecular techniques, we have generated a list of candidate genes from the literature, in order to identify plasticity mechanisms beyond FoxP/aPKC. Finally, in cooperation with Prof. Dr. Li Liu in Beijing, we will also validate the candidates identified in his screen for brain neurons involved in operant activity, the process that leads to self-learning. The Liu laboratory has already discovered neurons in the brain that are required for operant self-learning, irrespective of whether they express FoxP or not. In our collaboration, we will independently replicate the results from this laboratory and the laboratory in Beijing will replicate our most promising candidate line experiments.