Spatial learning-specific remodeling of the hippocampal palmitoylome

Synaptic plasticity in the hippocampus is a fundamental mechanism underlying learning and memory. The formation and stabilization of memory traces involve temporally distinct processes, ranging from rapid changes occurring within minutes to long-lasting adaptations that persist for days. Early phases rely on activity-dependent modulation of synaptic efficacy through signaling cascades and post-translational modifications. In contrast, later phases require structural remodeling and sustained changes in synaptic protein composition that support memory consolidation. Here, we sought to characterize the time-resolved dynamics of the hippocampal palmitoyl-proteome during spatial learning. Wistar rats performed spatial learning for 1 hour or 5 days in Morris water maze. Control groups were either cage control animals or yoked animals that were allowed to swim in Morris water maze but in the absence of the platform and external cues.Hippocampi were homogenized immediately after probe test. Using acyl-biotin exchange (ABE) combined with tandem mass tag (TMT)-based quantitative proteomics, we analyzed S-palmitoylation following acute learning (1 h) and repeated training (5 days). We identified distinct sets of synaptic proteins undergoing dynamic palmitoylation (differentially palmitoylated proteins, DPPs) across learning phases and mapped specific cysteine residues targeted by this modification. These findings provide a proteome-wide view of S-palmitoylation dynamics in vivo and highlight its role in learning and memory formation.