Prolonged Light and Synaptic Scaling in Xenopus Brain
This study aims to investigate how prolonged visual experience regulates homeostatic synaptic plasticity during neural development. Using the model organism Xenopus laevis tadpoles, we performed whole-brain transcriptomic profiling to compare animals reared under a standard light cycle (12 hours light/12 hours dark, 12LE) versus a prolonged light cycle (20 hours light/4 hours dark, 20LE).Prior electrophysiological and molecular data established that the 20LE condition leads to a reduction in miniature excitatory postsynaptic current (mEPSC) amplitude, dampened visually evoked responses, and downregulation of AMPA receptor subunits GluA1 and GluA2. This synaptic downscaling is driven by a two-stage process involving Rab5c-dependent receptor trafficking and class I HDAC-mediated epigenetic regulation, and is reversible upon return to normal light conditions.This RNA-Seq project is designed to uncover the genome-wide transcriptional mechanisms underlying these adaptations. Specifically, we seek to:Identify the global gene expression changes induced by prolonged light exposure.Define specific pathways related to synaptic transmission, AMPA receptor trafficking, chromatin modification (acetylation), and intrinsic neuronal excitability that are modulated by visual experience.Discover the upstream transcriptional regulatory networks that drive the observed electrophysiological and molecular phenotypes.By integrating transcriptomics with functional data, this study will provide a comprehensive molecular framework for understanding how environmental sensory input orchestrates transcriptional and post-transcriptional programs to guide the experience-dependent refinement and homeostasis of developing neural circuits.