Environmental dependent influences on the developmental refinement of excitatory inputs at an ultra-fast coincidence detector neuron

双耳符合检测依赖于内侧上橄榄(MSO)神经元中精确的兴奋-抑制相互作用。这种精确度是通过出生后发育后期的变化实现的，这一时期的标志是在听觉系统中建立了突出的结构-功能关系。在出生后发育后期，对MSO神经元的兴奋性输入是如何精炼的尚不清楚。在这个提议中，我们计划通过量化兴奋性电流的发育变化和轴突输入模式的形态来机械地研究这些过程。为了揭开这些变化的驱动力，我们将在全方位白噪音中饲养的沙土鼠身上进行这些实验，全方位白噪音会抑制相关的感觉空间线索。相反，通过消融耳蜗会消除声音诱发活动的影响。应用这两种形式的感觉操作将使我们能够区分声音诱发的活动或空间线索的体验对于MSO中功能上重要的电路细化是至关重要的。因此，我们的研究将为驱动超快符合探测神经元突触兴奋发展的机制提供一个定量的见解，这对声源定位非常重要。

Binaural coincidence detection relies on the precise excitation-inhibition interaction in neurons of the medial superior olive (MSO). This precision is achieved through alterations during late postnatal development, a period marked by the establishment of prominent structure-function relationships in the auditory system. How excitatory inputs to MSO neurons refine during late postnatal development is unknown. In this proposal, we plan to mechanistically investigate these processes, through quantification of the developmental changes of excitatory currents and the morphology of axonal input patterns. To unravel what drives these changes we will perform these experiments in gerbils raised in omnidirectional white noise, which suppresses relevant sensory spatial cues. Conversely, the impact of sound-evoked activity will be eliminated using cochlear ablations. Applying both forms of sensory manipulation will allow us to distinguish whether sound evoked activity or the experience of spatial cues is crucial for functionally important circuit refinements in the MSO. Thus, our study will provide a quantitative insight into mechanisms that drive the development of synaptic excitation at an ultrafast coincidence detector neuron important for sound source localization.