Development of hemispheric specialization pattern, a model of ontogenetic plasticity

大脑偏侧化，即大脑一侧对特定功能的支配，是动物王国神经元信息处理的核心特征，表明当大脑在两个大脑半球之间显示出劳动分工时，具有深刻的适应性优势。偏侧化处理是基于复杂的半球内和半球间机制，使独立的，半球特定的编码，但也交换，整合，或抑制信息。合作或独立处理的基本功能组织以及它的发展只是知之甚少。因此，本项目提案的目的是了解两个专门的大脑半球如何交流，产生适应性决策和行为控制，以及发育过程中基因与环境的相互作用如何塑造潜在的半球内和半球间过程。我们使用的不对称组织的视觉系统的鸽子作为一个模型来调查的影响，环境因素光，因为视觉不对称的出现依赖于有偏见的视觉刺激在胚胎发育过程中。特别是调查冲突情况下的反应选择（元控制）的任务，使我们能够探测内和半球间的过程，促进半球特定的专门的神经元回路的动态使用的相关性。我们要解决这个问题的三组实验比较元控制模式的鸽子和没有胚胎光的经验：实验一调查在多大程度上出现的半球优势冲突的选择取决于胚胎光刺激。实验二解决的问题，在多大程度上偏侧化模式的刺激分析依赖于个体发育的光的经验，并探讨了动力学和灵活性的元控制半球处理专业化。实验三旨在通过光遗传学的方法揭示冲突决策中半球优势的神经机制，为个体发育的感觉经验如何影响两个半球之间的有效互动提供重要线索。这可能至关重要地提高我们对侧化大脑的认知优势的理解，以及对发育和精神障碍的损害的理解。

Cerebral lateralization, the dominance of one brain side for a specific function, is a core feature of neuronal information processing in the animal kingdom indicating a profound fitness advantage when brains display a division of labour between the two brain halves. Lateralized processing is based on complex intra- and interhemispheric mechanisms enabling independent, hemispheric-specific encoding but also exchange, integration, or suppression of information. The underlying functional organization of cooperative or independent processing as well as its development is only poorly understood. It is therefore the aim of this project proposal to understand how two specialized brain halves communicate generating adaptive decisions and behavioural control and how gene-environment interactions during development shape the underlying intra- and interhemispheric processes. We use the asymmetrically organized visual system of pigeons as a model to investigate the impact of the environmental factor light since the emergence of visual asymmetries depend on biased visual stimulation during embryonic development. Especially tasks investigating response selection in conflict situations (metacontrol) enable us to probe the relevance of intra- and interhemispheric processes facilitating a dynamic use of hemispheric-specific specialized neuronal circuits. We want to address this topic by three sets of experiments comparing metacontrol pattern of pigeons with and without embryonic light experience:Experiment I investigates in how far the emergence of hemispheric dominance in conflict choices depends on embryonic light stimulation. Experiment II addresses the question in how far a lateralized mode of stimulus analysis depends on ontogenetic light experience and explores the dynamics and flexibility of metacontrol in relation to hemispheric processing specializations. Experiment III aims for unravelling the neuronal mechanisms underlying hemispheric dominance in conflict decisions by means of optogenetics.Our studies can provide important hints how ontogenetic sensory experience impacts efficient interactions between the two brain halves. This may crucially improve our understanding the cognitive advantages of a lateralized brain but also impairments in developmental and psychiatric disorders.