Identification of cell-type specific visual circuits in the ventral lateral geniculate nucleus

项目摘要 关于视觉世界的信息由视网膜捕获并由视网膜神经节细胞（RGC）传输到视网膜。 哺乳动物脑的多种视网膜受体区域，包括丘脑，下丘脑， 和中脑区域。这些长距离视网膜投射有一个组织逻辑， 有超过30种形态和功能不同的亚型， 并且有时是相互排斥的视网膜受体区域。许多这些视网膜受体核对于 特定视觉行为的执行。了解视觉信息是如何被处理和传输的 从视网膜到这些大脑区域需要对两者中的全部细胞群进行详细的表征。 区域和调查的类型的电路，他们组装成。这就要求我们对一个 视网膜和大脑中的细胞“零件清单”。对于皮层下视觉系统的某些部分， 目录存在。然而，对于某些视网膜受体细胞核，细胞部件列表要么特征不佳， 或者失踪一个这样的区域仍然缺乏特征性的是腹外侧膝状体核（vLGN）， 啮齿类动物的第三大视网膜受体区域。因此，我们的目标是应用最先进的单细胞 分辨率转录组测序与跨突触病毒追踪，以确定，在一个公正的方式，所有 vLGN中的视网膜受体细胞的类型。在初步研究中已经确定了两种这样的细胞类型 （Pvalb+和Penk+细胞），并且令人惊讶的是，这些细胞类型占据vLGN的不同的相邻亚层。这些 解剖学分区表明，该区域的视网膜受体细胞的亚型特异性层状分布 对于在并行通道中接收、处理和传输光衍生信号可能是重要的， 大脑我们将通过识别这两种亚型的具体输入和输出来检验这一假设。 vLGN神经元。

PROJECT SUMMARY Information about the visual world is captured by the retina and transmitted by retinal ganglion cells (RGCs) to a diverse array of retino-recipient regions of the mammalian brain, including those in thalamic, hypothalamic, and midbrain regions. There is an organizational logic to these long-range retinal projections where RGCs, of which there are more than three dozen morphologically and functionally distinct subtypes, project to distinct and sometimes mutually exclusive retinorecipient regions. Many of these retinorecipient nuclei are critical to the execution of specific visual behaviors. To understand how visual information is processed and transmitted from the retina to these brain regions requires a detailed characterization of the full cohort of cells in both regions and an investigation into the types of circuits they are assembled into. This requires us to catalogue a cellular “parts list” in both the retina and brain. For some parts of the subcortical visual system, such a catalogue exists. However, for some retino-recipient nuclei the cellular parts list is either poorly characterized or missing. One such region that remains poorly characterized is the ventral lateral geniculate nucleus (vLGN), the third largest retino-recipient region in rodents. Therefore, our goal is to apply state-of-the-art single cell resolution transcriptomic sequencing with trans-synaptic viral tracing to identify, in an unbiased fashion, all types of retino-recipient cells in the vLGN. Two such cell types have been identified in preliminary studies (Pvalb+ and Penk+ cells) and surprisingly, these cell types occupy distinct, adjacent sublamina of vLGN. These anatomical divisions suggest that subtype-specific laminar distribution of retino-recipient cells in this region may be important for receiving, processing, and transmitting light-derived signals in parallel channels through the brain. We will test this hypothesis by identifying the specific inputs and outputs of these two subtypes of vLGN neurons.