Functional diversity of somatostatin interneurons in visual cortical circuits

项目摘要： GABA能中间神经元对新皮层回路的正常发育和功能至关重要。在 特别是，表达肽生长抑素（SST-INs）的细胞被认为在这两个过程中起着关键作用。 自发的和感觉诱发的神经元活动，主要是通过它们对树突的强烈抑制， 兴奋性锥体神经元然而，不同类型的SST-IN在深层皮质中的功能作用， 层仍然未知。此外，尽管SST-INs在成年动物皮层浅层中的作用 已经得到很好的表征，它们在颗粒下层的功能是未知的。我们的初步数据显示 SST-Ins的性质在不同的皮质层上变化，因此可以起到不同的作用。进一步 探索这一观察，我们建议联合收割机的方法，包括光遗传学 操纵，2光子和病毒追踪。我们将测试以下假设：（1）SST-IN人群中， 视觉皮层的表层和深层有不同的反应，并受到行为的不同调节。 由于突触前输入的差异。(2)SST-IN种群在各层中的功能不同 并且在它们对感觉处理的影响上有所不同。我们的研究结果将提供前所未有的洞察力， SST-INs的功能及其与新皮层视觉处理的关系。

Project Summary: GABAergic interneurons are central to the normal development and function of neocortical circuits. In particular, cells that express the peptide somatostatin (SST-INs) are thought to play critical roles in both spontaneous and sensory-evoked neuronal activity, primarily via their robust inhibition of the dendrites of excitatory pyramidal neurons. However, the functional roles of the diverse classes of SST-INs in deep cortical layers remain unknown. Furthermore, whereas the role of SST-INs in superficial cortical layers of adult animals has been well characterized, their function in the infragranular layers is unknown. Our preliminary data suggest the properties of SST-Ins vary across different cortical layers and thus may serve different roles. To further explore this observation, we propose to combine a number of methodological approaches, including optogenetic manipulations, 2-photon and viral tracing. We will test the following hypotheses: (1) SST-IN populations in superficial and deep layers of visual cortex have distinct responses and differentially regulated by behavioral state due to differences in presynaptic inputs. (2) SST-IN populations are functionally distinct across the layers and differ in their impact on sensory processing. Our results will provide an unprecedented level of insight into the function of SST-INs and their relationship to visual processing in the neocortex.