Developmental Connectomics of the Mouse Cerebellum

作者：Nagaraju Dhanyasi, Yaron Meirovitch, Vikrant Kapoor, Alyssa M. Wilson, Shuohong Wang, Donglai Wei, Richard Schalek, Rong Ma, Yuelong Wu, Akhila Manthena, Diégo Cordero Cervantes, Zudi Lin, Yunlei Liu, Sanjana Chimaladinne, Benjamin Morris, Indu A. Vaddiparti, Yan Zhu, Sanjana Dokiburra, Riti Parampalli, Fuming Yang, Daniel R. Berger, Hanspeter Pfister, Venkatesh N. Murthy, Jeff W. Lichtman · 发表于：bioRxiv (Cold Spring Harbor Laboratory) · 年份：2025 · DOI：10.1101/2025.09.15.676403 · 被引用次数：2 · 研究领域：Mitochondrial Function and Pathology、Neonatal and fetal brain pathology、Neuroscience and Neuropharmacology Research

Abstract To uncover the developmental processes that establish the precise patterns of synaptic connectivity in the CNS, we employed a connectomic approach in the mouse cerebellar cortex between birth and 2 weeks of age. There were dramatic quantitative and qualitative changes in the structure and connectivity of cerebellar cells. Parallel fiber synapses onto Purkinje cells increased ∼500-fold, with the most rapid growth taking place a week after birth. To support this profound synaptogenesis, Purkinje cells generated thousands of transient parallel fiber-oriented filopodia that received nascent synapses from parallel fibers. Importantly, we find that granule cells initiate synaptic output onto Purkinje cells only after receiving mossy fiber input, revealing a sequential, input-dependent logic for circuit assembly. In sharp contrast to the concurrent pruning of climbing fiber inputs, parallel fiber connectivity expanded and became highly individualized during development. Despite anatomical overlap, neighboring Purkinje cells share significantly fewer parallel fiber inputs than expected by chance. Moreover, parallel fibers themselves diverged spatially, further enforcing selective input allocation and resulting in highly specific parallel fiber cohorts for each Purkinje cell. Our findings uncover a mechanistic sequence in which early afferent activity and transient cellular structures guide the selective wiring and expansion of parallel fiber input to Purkinje cells, establis...