Mechanisms and impact of NMDA-receptor signaling during sensory processing in an echo-locating circuit

nmda受体在神经元可塑性中的作用已被证实。然而，它们在细胞内电压信号和感觉处理中的作用尚不清楚，但它们与动作电位放电率的放大有关。为了了解这种NMDA依赖性的放电率放大的细胞基础及其对感觉信息处理的影响，我们将在体内和体外记录外侧小丘背核（DNLL）的神经元-听觉脑干结构对双耳听力很重要。我们将确定突触的兴奋和抑制与nmda受体电导的相互作用，以了解它们对体外细胞内电压信号传导的贡献。使用体内药理学，我们将回答NMDA受体对声音驱动放电率的影响。因此，DNLL一方面作为读出核，其中nmda受体对传递双耳信息的影响将被量化。另一方面，我们将在体内检测DNLL水平上的直接双耳相互作用，以了解nmda受体对抑制和兴奋之间相互作用的影响。我们假设，这些相互作用可能是至关重要的，在终止一个长期持续的抑制，被认为是一个细胞相关的抑制声源在回声。

The role of NMDA-receptors in neuronal plasticity is well established. However, their role in intracellular voltage-signaling and sensory processing is less well characterized, yet they are implicated in amplifying action potential firing rates. To understand the cellular basis for this NMDA dependent amplification of firing rate, its influence on sensory information processing we will perform in vivo and in vitro recordings of neurons in the dorsal nucleus of the lateral lemniscus (DNLL) - an auditory brainstem structure important for binaural hearing. We will determine the synaptic interactions of excitation and inhibition with NMDA-receptor conductances to understand their contributions to intracellular voltage-signaling in vitro. Using in vivo pharmacology we will answer what impact NMDA receptors have on sound driven firing rates. Thereby, the DNLL serves on the one hand as a read out nucleus where the impact of NMDA-receptors on relaying binaural information will be quantified. On the other hand we will assay in vivo the direct binaural interactions at the level of the DNLL to understand the influence of NMDA-receptors on interactions between inhibition and excitation. We hypothesize that these interactions might be crucial in terminating a long lasting inhibition that is regarded as a cellular correlate for the suppression of sound sources during echoes.