Abstract
Chronic sleep deprivation (CSD) is a pervasive global public health concern known to disrupt synaptic plasticity, impair memory consolidation, and induce cognitive deficits localized predominantly within the hippocampus. Although sleep loss is acknowledged to remodel the structural integrity of neural circuits, the precise molecular dynamics governing presynaptic vesicle machinery remain incompletely understood. In this study, we conducted a rigorous quantitative proteomic analysis of isolated synaptosomes and synaptic vesicle-enriched fractions from the hippocampus of C57BL/6J mice subjected to 72 hours of continuous sleep deprivation using a gentle handling protocol. Employing tandem mass tag (TMT) labeling coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS), we quantified 2,842 non-redundant proteins, identifying 147 significantly dysregulated synaptic proteins. Notably, core components of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex, including synaptobrevin-2 (VAMP2) and syntaxin-1A, alongside regulatory proteins such as synapsin-1, synaptotagmin-1, and complexin-2, exhibited pronounced downregulation. Pathway enrichment analysis revealed marked disruptions in vesicle docking, calcium-triggered exocytosis, and neurotransmitter recycling cascades. Immunoblotting and confocal immunofluorescence assays corroborated the depletion of key SNARE constituents in CA1 and CA3 subfields. These quantitative molecular findings indicate that prolonged wakefulness attenuates synaptic efficacy by destabilizing vesicle trafficking and priming machinery, offering mechanistic insight into the neurobiological underpinnings of cognitive decline following sleep disruption.
