Opioid addiction is characterized by compulsive drug seeking and taking behavior, which is thought to result from persistent neuroadaptations. However, there is a lack of information about the changes at both the cellular and molecular levels occurring after cessation of drug administration. The aim of our study was to determine alterations of both phosphoproteome and proteome in selected brain regions of the rats (brain cortex, hippocampus, striatum, and cerebellum) 3 months after cessation of 10-day morphine treatment. Phosphoproteome profiling was performed by Pro-Q® Diamond staining. The gel-based proteomic approach accompanied by label-free quantification (MaxLFQ) was used for characterization of proteome changes. The phosphoproteomic analysis revealed the largest change in the hippocampus (14); only few altered proteins were detected in the forebrain cortex (5), striatum (4), and cerebellum (3). The change of total protein composition, determined by 2D electrophoresis followed by LFQ analysis, identified 22 proteins with significantly altered expression levels in the forebrain cortex, 19 proteins in the hippocampus, 12 in the striatum and 10 in the cerebellum. The majority of altered proteins were functionally related to energy metabolism and cytoskeleton reorganization. As the most important change we regard down-regulation of 14-3-3 proteins in rat cortex and hippocampus. Our findings indicate that i) different parts of the brain respond in a distinct manner to the protracted morphine withdrawal, ii) characterize changes of protein composition in these brain parts, and iii) enlarge the scope of evidence for adaptability and distinct neuroplasticity proceeding in the brain of drug-addicted organism.

Department of Physiology Faculty of Science Charles University Vinicna 7 128 43 Prague 2 Czech Republic

Laboratory of Membrane Receptors Department of Biomathematics Institute of Physiology of the Czech Academy of Sciences Videnska 1083 142 20 Prague 4 Czech Republic

Laboratory of Translational Metabolism Institute of Physiology of the Czech Academy of Sciences Videnska 1083 142 20 Prague 4 Czech Republic

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The Dose-Dependent Effects of Multifunctional Enkephalin Analogs on the Protein Composition of Rat Spleen Lymphocytes, Cortex, and Hippocampus; Comparison with Changes Induced by Morphine

Alterations in the Proteome and Phosphoproteome Profiles of Rat Hippocampus after Six Months of Morphine Withdrawal: Comparison with the Forebrain Cortex

Proteomic Analysis Unveils Expressional Changes in Cytoskeleton- and Synaptic Plasticity-Associated Proteins in Rat Brain Six Months after Withdrawal from Morphine