Modulation of spatial representations within the early auditory pathway by active sensing

通过主动传感调节早期听觉通路内的空间表征

• 批准号: 504753924
• 负责人: Privatdozent Dr. Michael Pecka
• 金额: --
• 依托单位: Lehrstuhl für Neurobiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/504753924?language=en
• 关键词: Modulation; spatial; representations; within; early

Localizing and identifying sensory objects while navigating the environment are fundamental brain functions. However, how individual objects are neuronally represented during unrestricted self-motion is mostly unexplored. Based on an earlier project funded by the DFG, we recently developed a new freely moving experimental paradigm to study auditory processing and sound perception (Sensory Island Task, SIT). Using SIT, we observed previously unreported spatial sound-source representations in primary auditory cortex (A1): the egocentric angle preference of A1 neurons changed significantly depending on the task-specific identity of the sound-source, revealing a novel cortical computation principle for naturalistic sensing during self-motion. These profoundly new findings raise fundamental questions about the underlying circuits and mechanisms. Specifically, the recurrent connectivity between the midbrain hub of the Inferior Colliculus (IC), the Medial Geniculate Body (MGB) in the thalamus and A1 has been suggested to be involved in the transformation and selective gating of sensory information to form perceptual representations. It follows that this network is a prime candidate for the organization of the new spatial representations that we have identified. Thus, to gain a mechanistic understanding of our findings of identity-specific spatial tuning in A1, we aim to study how the same behavioral paradigm affect spatial representations in IC and MGB. To this end, we plan to record chronically in these brain regions during active localization and unrestricted self-motion in SIT. Inspired by our findings in A1, we will determine to what extent spatial representations differ from traditionally observed pure egocentric tuning. Moreover, using targeted optogenetic manipulations, we will dissect the role of the prominent feedback of A1 to IC and MGB for the generation of spatial representations during SIT as well as for behavioral performance.

在环境中导航时定位和识别感官对象是大脑的基本功能。然而，在不受限制的自我运动过程中，单个物体是如何以神经元的形式呈现的，大多是未被探索的。在DFG资助的一个早期项目的基础上，我们最近开发了一种新的自由移动的实验范式来研究听觉加工和声音感知(Sensory Island Task，SIT)。利用SIT，我们在初级听觉皮质(A1)观察到了以前未报道的空间声源表征：A1神经元的自我中心角度偏好显著地取决于声源的任务特异性身份，揭示了一种新的皮质计算原理，用于在自我运动中进行自然感觉。这些深刻的新发现提出了关于潜在电路和机制的根本问题。具体地说，下丘的中脑中枢(IC)、丘脑的内侧膝状体(MGB)和A1之间的经常性连接被认为参与了感觉信息的转换和选择性选通，以形成知觉表征。因此，该网络是组织我们已经确定的新的空间表示的主要候选者。因此，为了机械地理解我们在A1中的身份特定空间调节的发现，我们的目标是研究相同的行为范式如何影响IC和MGB中的空间表征。为此，我们计划在SIT中进行主动定位和不受限制的自我运动期间，在这些脑区进行慢性记录。受到我们在A1中的发现的启发，我们将确定空间表示与传统观察到的纯粹自我中心调整的不同程度。此外，利用有针对性的光遗传操作，我们将剖析A1对IC和MGB的显著反馈在SIT期间空间表征的生成以及对行为表现的作用。