Investigation into the Characteristics of Metabolite and Protein Changes and Associated Pathways in Ketamine-induced Conditioned Place Preference Rat Model Based on Multiomics Analysis

Background: Ketamine demonstrates therapeutic potential but also high abuse liability. The neurobiological mechanisms underlying its addiction remain unclear. This study employs integrated metabolomics and proteomics to investigate alterations in endogenous metabolites and proteins across brain regions and plasma in a rat model of ketamine addiction. Materials and Methods: A ketamine addiction model was established by repeated administration (20 mg/kg) in Sprague–Dawley rats, with behavioral validation through conditioned place preference (CPP). Prefrontal cortex (PFC), striatum, and plasma samples were analyzed using ultra-high-performance liquid chromatography-Q-Orbitrap mass spectrometry-based metabolomics and TMT-based quantitative proteomics. Multivariate statistics and joint multiomics pathway analysis were applied. Results: Ketamine administration induced significant CPP ( P < 0.05). Proteomics revealed 245 differentially expressed proteins in the PFC, enriched in dopaminergic, glutamatergic, and GABAergic synapses, and 188 in the striatum related to Alzheimer’s disease, retrograde endocannabinoid, and cAMP signaling. Plasma proteomics showed 156 differential proteins, primarily involved in complement, coagulation cascades, glycolysis, and gluconeogenesis. In the PFC, 60 metabolites were altered, like amino sugar and nucleotide sugar metabolism, while 132 metabolites in the striatum were linked to retrograde endocannabinoid signaling (ECS), dopaminergic synapse, and purine metabolism. Plasma metabolomics identified significant changes, such as arginine and proline metabolism. Joint multiomics pathway analysis highlighted consistent disruptions in glutamate/glutamine metabolism, retrograde ECS, purine metabolism, etc., across tissues. Conclusion: Ketamine addiction induces system-wide alterations in energy metabolism and neurotransmitter systems, with pronounced effects in the PFC and striatum, and detectable changes in plasma. These findings elucidate key enriched and interconnected metabolic pathways, advancing our mechanistic understanding of ketamine addiction and revealing potential targets for intervention.