Updated project metadata. This project employed ultrasensitive proteomics in the discovery setting utilizing microanalytical capillary electrophoresis electrospray ionization (CE-ESI) and trapped ion mobility high-resolution mass spectrometry (TimsTOF HRMS) to quantify proteomic changes during development in the suprachiasmatic nucleus (SCN), before and after the onset of photoreceptor-dependent visual function. Results from this work highlight the maturation of oligodendrocyte myelination as well as extracellular matrix proteins with implications for critical-period plasticity. This work marks the first integration of ultrasensitive proteomics by CE-ESI TimsTOF HRMS with super-resolution STORM microscopy provide, expanding analytical resources to help better understand the brain and vision.