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Lark AR, Nass SR, Hahn YK, Gao B, Milne GL, Knapp PE, Hauser KF. HIV-1 Tat and morphine interactions dynamically shift striatal monoamine levels and exploratory behaviors over time. J Neurochem 2024; 168:185-204. [PMID: 38308495 PMCID: PMC10922901 DOI: 10.1111/jnc.16057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 12/28/2023] [Accepted: 01/10/2024] [Indexed: 02/04/2024]
Abstract
Despite the advent of combination anti-retroviral therapy (cART), nearly half of people infected with HIV treated with cART still exhibit HIV-associated neurocognitive disorders (HAND). HAND can be worsened by co-morbid opioid use disorder. The basal ganglia are particularly vulnerable to HIV-1 and exhibit higher viral loads and more severe pathology, which can be exacerbated by co-exposure to opioids. Evidence suggests that dopaminergic neurotransmission is disrupted by HIV exposure, however, little is known about whether co-exposure to opioids may alter neurotransmitter levels in the striatum and if this in turn influences behavior. Therefore, we assayed motor, anxiety-like, novelty-seeking, exploratory, and social behaviors, and levels of monoamines and their metabolites following 2 weeks and 2 months of Tat and/or morphine exposure in transgenic mice. Morphine decreased dopamine levels, but significantly elevated norepinephrine, the dopamine metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), and the serotonin metabolite 5-hydroxyindoleacetic acid, which typically correlated with increased locomotor behavior. The combination of Tat and morphine altered dopamine, DOPAC, and HVA concentrations differently depending on the neurotransmitter/metabolite and duration of exposure but did not affect the numbers of tyrosine hydroxylase-positive neurons in the mesencephalon. Tat exposure increased the latency to interact with novel conspecifics, but not other novel objects, suggesting the viral protein inhibits exploratory behavior initiation in a context-dependent manner. By contrast, and consistent with prior findings that opioid misuse can increase novelty-seeking behavior, morphine exposure increased the time spent exploring a novel environment. Finally, Tat and morphine interacted to affect locomotor activity in a time-dependent manner, while grip strength and rotarod performance were unaffected. Together, our results provide novel insight into the unique effects of HIV-1 Tat and morphine on monoamine neurochemistry that may underlie their divergent effects on motor and exploratory behavior.
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Affiliation(s)
| | | | | | - Benlian Gao
- Neurochemistry Core, Vanderbilt Brain Institute, Vanderbilt University
| | - Ginger L. Milne
- Neurochemistry Core, Vanderbilt Brain Institute, Vanderbilt University
| | - Pamela E. Knapp
- Department of Pharmacology & Toxicology
- Department of Anatomy and Neurobiology
- Institute for Drug and Alcohol Studies, Virginia Commonwealth University
| | - Kurt F. Hauser
- Department of Pharmacology & Toxicology
- Department of Anatomy and Neurobiology
- Institute for Drug and Alcohol Studies, Virginia Commonwealth University
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2
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Campos-Jurado Y, Martí-Prats L, Zornoza T, Polache A, Granero L, Cano-Cebrián MJ. Regional differences in mu-opioid receptor-dependent modulation of basal dopamine transmission in rat striatum. Neurosci Lett 2016; 638:102-108. [PMID: 27986497 DOI: 10.1016/j.neulet.2016.12.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 12/05/2016] [Accepted: 12/12/2016] [Indexed: 11/30/2022]
Abstract
The nigrostriatal dopamine system is implicated in the regulation of reward and motor activity. Dopamine (DA) release in dorsal striatum (DS) is controlled by the firing rate of DA neurons in substantia nigra pars compacta. However, influences at terminal level, such as those involving activation of mu opioid receptors (MORs), can play a key role in determining DA levels in striatum. Nonetheless, published data also suggest that the effect of opioid drugs on DA levels may differ depending on the DS subregion analyzed. In this study, in vivo microdialysis in rats was used to explore this regional dependence. Changes in basal DA levels induced by local retrodialysis application of DAMGO (selective MORs agonist) in three different subregions of DS along the rostro-caudal axis were studied. Our results indicate that whereas administration of 10μM DAMGO into the rostral and caudal DS significantly reduced DA levels, in medial DS an increase in DA levels was observed. These data reveal a regional-dependent MOR modulation of DA release in DS, similar to that described in the ventral striatum. Our findings may lead to a better understanding of the nigrostriatal DA system regulation.
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Affiliation(s)
- Y Campos-Jurado
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, University of Valencia, Valencia, Spain
| | - L Martí-Prats
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, University of Valencia, Valencia, Spain
| | - T Zornoza
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, University of Valencia, Valencia, Spain
| | - A Polache
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, University of Valencia, Valencia, Spain
| | - L Granero
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, University of Valencia, Valencia, Spain
| | - M J Cano-Cebrián
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, University of Valencia, Valencia, Spain.
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3
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Modulation of nucleus accumbens connectivity by alcohol drinking and naltrexone in alcohol-preferring rats: A manganese-enhanced magnetic resonance imaging study. Eur Neuropsychopharmacol 2016; 26:445-55. [PMID: 26851200 DOI: 10.1016/j.euroneuro.2016.01.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 12/31/2015] [Accepted: 01/15/2016] [Indexed: 11/23/2022]
Abstract
The nonselective opioid receptor antagonist naltrexone is now used for the treatment of alcoholism, yet naltrexone's central mechanism of action remains poorly understood. One line of evidence suggests that opioid antagonists regulate alcohol drinking through interaction with the mesolimbic dopamine system. Hence, our goal here was to examine the role of the nucleus accumbens connectivity in alcohol reinforcement and naltrexone's actions using manganese-enhanced magnetic resonance imaging (MEMRI). Following long-term free-choice drinking of alcohol and water, AA (Alko Alcohol) rats received injections of MnCl2 into the nucleus accumbens for activity-dependent tracing of accumbal connections. Immediately after the accumbal injections, rats were imaged using MEMRI, and then allowed to drink either alcohol or water for the next 24h. Naltrexone was administered prior to the active dark period, and the second MEMRI was performed 24h after the first scan. Comparison of signal intensity at 1 and 24h after accumbal MnCl2 injections revealed an ipsilateral continuum through the ventral pallidum, bed nucleus of the stria terminalis, globus pallidus, and lateral hypothalamus to the substantia nigra and ventral tegmental area. Activation was also seen in the rostral part of the insular cortex and regions of the prefrontal cortex. Alcohol drinking resulted in enhanced activation of these connections, whereas naltrexone suppressed alcohol-induced activity. These data support the involvement of the accumbal connections in alcohol reinforcement and mediation of naltrexone's suppressive effects on alcohol drinking through their deactivation.
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Lan KC, Chang AC, Liu SH, Ho IK, Lin-Shiau SY. Enhancing effects of morphine on methamphetamine-induced reinforcing behavior and its association with dopamine release and metabolism in mice. J Neurochem 2009; 109:382-92. [PMID: 19245664 DOI: 10.1111/j.1471-4159.2009.05998.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polydrug abuse has become a significant problem worldwide, and the combined use of methamphetamine (MA) and morphine (M) is now highly prevalent among addicts. In the present study, we investigated the neurobehavioral effects of repeated treatment regimens of these drugs (i.p. administration of 0.75 mg/kg/day MA, 5 mg/kg/day M, and their combination for five consecutive days followed by once weekly for five consecutive weeks) in mice. In addition, we used an in vivo microdialysis technique to study the changes in extracellular concentrations of dopamine (DA) and its metabolites in the mouse striatum after challenge administration of these drugs. The results showed that systemic M increased MA-induced conditioned place preference (CPP), as revealed by higher CPP values which were also maintained for a longer duration compared with those induced by an identical dose of MA or M alone. Subsequent to challenge with combined MA and M, mice exhibited an increase in stereotyped behavior, which appeared to be associated with an elevation of extracellular concentration of DA in the striatum. Our findings suggest that M not only produces synergistic effects on MA-induced CPP, but also interacts with MA to induce stereotyped behavioral sensitization which is mediated by an increase in DA outflow in the striatum. These findings provide insight into the behavioral and neurochemical basis responsible for the combined abuse liability of MA and M.
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Affiliation(s)
- Kuo-Cheng Lan
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
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Hipólito L, Sánchez-Catalán MJ, Zanolini I, Polache A, Granero L. Shell/core differences in mu- and delta-opioid receptor modulation of dopamine efflux in nucleus accumbens. Neuropharmacology 2008; 55:183-9. [PMID: 18582908 DOI: 10.1016/j.neuropharm.2008.05.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Revised: 04/16/2008] [Accepted: 05/11/2008] [Indexed: 10/22/2022]
Abstract
The mu- and delta-opioid receptors located at the terminal level in nucleus accumbens are involved in the opiate modulation of dopamine release in this brain area. However, recent studies suggest that the effects of opioid drugs on the core subregion of nucleus accumbens may completely differ from those observed in the shell. We used in vivo microdialysis to simultaneously apply selective mu- and delta-opioid receptor agonists and to measure extracellular levels of dopamine in three subregions of the accumbens, namely shell, core, and the transition zone between them. The regional analysis of these subregions of the accumbens demonstrated that basal levels of dopamine and its metabolites were higher in the core, and decreased from this subregion to the shell. Retrodialysis application to the core of both the selective mu-receptor agonist ([D-Ala(2), N-Me-Phe(4), Gly(5)-ol]-enkephalin (DAMGO) (1 micromol/L)) and of the selective delta-opioid receptor agonist ([D-Pen(2), D-Pen(5)]-enkephalin (DPDPE) (50 nmol/L)) increased the dialysate levels of dopamine. However, the application of these drugs to the shell significantly reduced the dopamine levels in this subregion. Local application of the same doses of these drugs in the transition zone between the shell and the core did not significantly affect the dopamine levels in dialysates. These results suggest that the opioid circuits modulating dopaminergic activity in the shell could differ from those in the core of the nucleus accumbens.
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Affiliation(s)
- Lucía Hipólito
- Departament de Farmacia i Tecnología Farmacèutica, Universitat de València, Avda Vicente Andrés Estellés s/n, 46100 Burjassot, Spain
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Kamerman PR, Becker N, Fick LG. Interactions between metoclopramide and morphine: enhanced antinociception and motor dysfunction in rats. Clin Exp Pharmacol Physiol 2007; 34:106-12. [PMID: 17201744 DOI: 10.1111/j.1440-1681.2007.04533.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1. Opioid analgesics and anti-emetics are often used concomitantly to treat pain and nausea and vomiting in people with malignant disease. We investigated interactions between the opioid analgesic morphine and the anti-emetic metoclopramide, a dopamine D2 receptor antagonist, on nociception and gross motor function. 2. To assess for antinociceptive interactions, 11 Sprague-Dawley rats were injected intraperitoneally with morphine (5.0 mg/kg) or saline in combination with metoclopramide (0.5, 1.5 and 5.0 mg/kg) or saline and, 30 min later, the tail-flick latencies to a noxious thermal stimulus (49 degrees C water) were measured. Immediately thereafter we induced reperfusion hyperalgesia in the rats' tails using a tourniquet cuff and tested nociception again. Because, in addition to its ability to block D2 receptors, metoclopramide is also a weak 5-HT(3) receptor antagonist, we assessed in a further 11 rats whether any antinociceptive interactions occurred between morphine (5.0 mg/kg) and ondansetron (0.2 and 2.0 mg/kg), an anti-emetic that selectively antagonizes 5-HT(3) receptors. To assess for motor interactions, we injected another group of nine rats with morphine (5.0 mg/kg) or saline in combination with metoclopramide (0.5 and 5.0 mg/kg) or saline and tested the ability of the animals to run on an 80 mm diameter rod rotating at 25 r.p.m. for 30 min. 3. Metoclopramide was not inherently analgesic or antihyperalgesic, but the highest dose of metoclopramide (5.0 mg/kg) enhanced the analgesic and antihyperalgesic effects of morphine. Neither dose of ondansetron was analgesic or antihyperalgesic or enhanced the antinociceptive actions of morphine. 4. Only the high dose of metoclopramide compromised running performance when administered with saline. However, coadministering morphine with metoclopramide (both doses) decreased motor performance. 5. Therefore, metoclopramide, possibly through its actions on D2 receptors and not 5-HT(3) receptors, enhances the analgesic and antihyperalgesic effects of morphine, but morphine exacerbates metoclopramide-induced motor dysfunction in rats.
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Affiliation(s)
- Peter R Kamerman
- School of Physiology, University of the Witwatersrand, Johannesburg, South Africa.
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Hagelberg N, Kajander JK, Någren K, Hinkka S, Hietala J, Scheinin H. Mu-receptor agonism with alfentanil increases striatal dopamine D2 receptor binding in man. Synapse 2002; 45:25-30. [PMID: 12112410 DOI: 10.1002/syn.10078] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Animal studies indicate that mu-opioids indirectly modulate neurotransmission in the nigrostriatal dopaminergic pathway. We used positron emission tomography (PET) to study the effects of alfentanil (a mu-opioid receptor agonist) on striatal dopamine D2 receptor binding in eight healthy male volunteers. D2 receptor binding was determined by using [(11)C]raclopride as radioligand. Each subject underwent two PET sessions on the same day, the first without the drug (control) and the second during alfentanil infusion. Alfentanil was administered as target-controlled infusion to maintain pseudo steady-state plasma concentration of 80 ng/ml throughout the PET session. A freeze lesion model was used for pain testing at the end of both PET sessions. A mechanical pain stimulus of 5 N was rated by the subjects using a visual analog scale. Regions of interest for the putamen, caudate nucleus, and cerebellum were drawn on MRI images and transferred to PET images. Alfentanil increased the binding potential of [(11)C]raclopride in the putamen by 6.0% (P = 0.04) and in the caudate nucleus by 7.4% (P = 0.008). Alfentanil caused a small reduction in respiratory rate (P = 0.046) and oxygen saturation (P < 0.001), and a moderate consistent increase in end-tidal CO(2) (P < 0.001). Pain scores were significantly smaller after alfentanil PET scan (median VAS 9 (0-42) vs. 23.5 (15-52), P = 0.008). These results indicate that pharmacologically relevant concentrations of alfentanil increase D2 dopamine receptor binding in the striatum in man. This increase is assumed to reflect reduced dopamine release.
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Affiliation(s)
- Nora Hagelberg
- Department of Anesthesiology and Intensive Care, Turku University Central Hospital, Turku, Finland
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Abstract
The effects of morphine on extracellular dopamine levels in brain have never been studied over a wide range of doses within a single study. This has made it difficult to make definitive interpretations of drug interactions with morphine. An inhibition of morphine-induced increases in dopamine could be interpreted as either antagonism or potentiation depending the shape of the morphine dose-response curve. Accordingly, the aim of the present study was to determine the effects of a wide range of morphine doses (0, 5, 10, 20 and 30 mg/kg, i.p.) on extracellular dopamine, DOPAC and HVA levels in the nucleus accumbens and striatum of awake and freely moving female Sprague-Dawley rats. The results show that, in both brain regions, the dose-response curve for morphine-induced increases in dopamine is non-monotonic while the dose-response curve for morphine-induced increases in DOPAC and HVA is monotonic in the nucleus accumbens. The results of this study are discussed in terms of their implications for interpreting drug interactions with morphine and with relationship to morphine's mode of action at mu and kappa opioid receptors.
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Affiliation(s)
- I M Maisonneuve
- Center for Neuropharmacology and Neuroscience, MC-136, Albany Medical College, 47 New Scotland Ave, Albany, NY 12208, USA.
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9
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Abstract
This paper is the twenty-second installment of the annual review of research concerning the opiate system. It summarizes papers published during 1999 that studied the behavioral effects of the opiate peptides and antagonists, excluding the purely analgesic effects, although stress-induced analgesia is included. The specific topics covered this year include stress; tolerance and dependence; learning, memory, and reward; eating and drinking; alcohol and other drugs of abuse; sexual activity, pregnancy, and development; mental illness and mood; seizures and other neurologic disorders; electrical-related activity; general activity and locomotion; gastrointestinal, renal, and hepatic function; cardiovascular responses; respiration and thermoregulation; and immunologic responses.
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Affiliation(s)
- A L Vaccarino
- Department of Psychology, University of New Orleans, New Orleans, LA 70148, USA.
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