AMPA Receptor Plasticity in Accumbens Core Contributes to Incubation of Methamphetamine Craving

• Published in: Biological psychiatry (1969) Vol. 80; no. 9; pp. 661 - 670
• Main Authors: Scheyer, Andrew F, Loweth, Jessica A, Christian, Daniel T, Uejima, Jamie, Rabei, Rana, Le, Tuan, Dolubizno, Hubert, Stefanik, Michael T, Murray, Conor H, Sakas, Courtney, Wolf, Marina E
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2016
• Subjects: Animals; Ca2+-permeable AMPA receptors; Craving - drug effects; Craving - physiology; Cues; Drug-Seeking Behavior; Excitatory Postsynaptic Potentials - drug effects; Extended-access drug self-administration; Incubation of craving; Long-Term Synaptic Depression - drug effects; Male; Metabotropic glutamate receptor 1 (mGluR1); Methamphetamine; Methamphetamine - administration & dosage; Nucleus accumbens; Nucleus Accumbens - drug effects; Nucleus Accumbens - metabolism; Psychiatry; Rats; Rats, Sprague-Dawley; Receptors, AMPA - antagonists & inhibitors; Receptors, AMPA - metabolism; Receptors, AMPA - physiology; Receptors, Metabotropic Glutamate - metabolism; Spermine - administration & dosage; Spermine - analogs & derivatives; Substance Withdrawal Syndrome - metabolism; Substance Withdrawal Syndrome - physiopathology; Nucleus accumbens; Extended-access drug self-administration; Ca 2+-permeable AMPA receptors; Metabotropic glutamate receptor 1 (mGluR1); Methamphetamine; Incubation of craving; Ca2+-permeable AMPA receptors; Ca(2+)-permeable AMPA receptors
• ISSN: 0006-3223; 1873-2402
• DOI: 10.1016/j.biopsych.2016.04.003

Abstract Background The incubation of cue-induced drug craving in rodents provides a model of persistent vulnerability to craving and relapse in human addicts. After prolonged withdrawal, incubated cocaine craving depends on strengthening of nucleus accumbens (NAc) core synapses through incorporation of Ca2+ -permeable alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (CP-AMPARs). Through metabotropic glutamate receptor 1 (mGluR1)–mediated synaptic depression, mGluR1 positive allosteric modulators remove CP-AMPARs from these synapses and thereby reduce cocaine craving. This study aimed to determine if similar plasticity accompanies incubation of methamphetamine craving. Methods Rats self-administered saline or methamphetamine under extended-access conditions. Cue-induced seeking tests demonstrated incubation of methamphetamine craving. After withdrawal periods ranging from 1 to >40 days, rats underwent one of the following procedures: 1) whole-cell patch clamp recordings to characterize AMPAR transmission, 2) intra–NAc core injection of the CP-AMPAR antagonist 1-naphthyl acetyl spermine followed by a seeking test, or 3) systemic administration of a mGluR1 positive allosteric modulator followed by a seeking test. Results Incubation of methamphetamine craving was associated with CP-AMPAR accumulation in NAc core, and both effects were maximal after ~1 week of withdrawal. Expression of incubated craving was decreased by intra–NAc core 1-naphthyl acetyl spermine injection or systemic mGluR1 positive allosteric modulator administration. Conclusions These results are the first to demonstrate a role for the NAc in the incubation of methamphetamine craving and describe adaptations in synaptic transmission associated with this model. They establish that incubation of craving and associated CP-AMPAR plasticity occur much more rapidly during withdrawal from methamphetamine compared with cocaine. However, a common mGluR1-based therapeutic strategy may be helpful for recovering cocaine and methamphetamine addicts.