ArticlePsychopharmacology2005
Cocaine and heroin ('speedball') self-administration: the involvement of nucleus accumbens dopamine and mu-opiate, but not delta-opiate receptors.
Article in Psychopharmacology, 2005. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers.
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Who cites it
13 citing papers in PubMed, 41 citations in OpenAlex.
- Sustained release d-amphetamine reduces cocaine but not 'speedball'-seeking in buprenorphine-maintained volunteers: a test of dual-agonist pharmacotherapy for cocaine/heroin polydrug abusers.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2010Trial
- The need to incorporate polysubstance use in neuropsychopharmacology research: Biological lessons and new opportunities.Addiction neuroscience · 2026Article
- Mu-opioid and nociceptin receptors show divergent, cell-type-specific actions in the mesocorticolimbic reward system in opioid use disorder.Frontiers in cellular neuroscience · 2026Review
- Adulterants present in the San Diego county fentanyl supply: a laboratory analysis of seized law enforcement samples.BMC public health · 2024Article
- Goofballing of Opioid and Methamphetamine: The Science Behind the Deadly Cocktail.Frontiers in pharmacology · 2022Review
- Agonist-induced phosphorylation bar code and differential post-activation signaling of the delta opioid receptor revealed by phosphosite-specific antibodies.Scientific reports · 2020Article
- Dopamine D1 receptor antagonist reduces stimulant-induced conditioned place preferences and dopamine receptor supersensitivity.Naunyn-Schmiedeberg's archives of pharmacology · 2020Article
- Naloxone induces frequent jumping after chronic morphine and methamphetamine co-administration in rats.Basic and clinical neuroscience · 2014Article
- Upregulation of nerve growth factor in central amygdala increases sensitivity to opioid reward.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2012Article
- Powerful behavioral interactions between methamphetamine and morphine.Pharmacology, biochemistry, and behavior · 2011Article
- Reward processing by the opioid system in the brain.Physiological reviews · 2009Review
- Ethanol-induced delta-opioid receptor modulation of glutamate synaptic transmission and conditioned place preference in central amygdala.Neuroscience · 2009Article
- Self-administered heroin and cocaine combinations in the rat: additive reinforcing effects-supra-additive effects on nucleus accumbens extracellular dopamine.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2006Article
Corrections and comments
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Authors and funding
4 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
rationaleThe combined administration of heroin and cocaine ('speedball') is common among intravenous drug users. Dopamine receptors in the nucleus accumbens play a key role in cocaine self-administration; however, their role in speedball self-administration is unknown, as is the role of opiate receptors in this region.
objectivesThe effect of blocking dopamine D1, D2, mu-opiate or delta-opiate receptors in the nucleus accumbens on the intravenous self-administration of combined heroin and cocaine was examined in rats.
methodsRats with bilateral cannulae implanted into the nucleus accumbens were trained to self-administer intravenous speedball (ratio of cocaine/heroin, 17:1) under a progressive ratio (PR) schedule. Prior to their self-administration session, rats were then microinjected with the dopamine D1 receptor antagonist SCH 23390 (1 and 6 nmol side(-1)), the D2 receptor antagonist raclopride (3 and 10 nmol side(-1)), the mu-opiate receptor antagonist CTOP (0.1, 0.3 and 1.0 nmol side(-1)), the delta-opiate receptor antagonist naltrindole (1.0, 3.0 and 10 nmol side(-1)) or a cocktail of SCH 23390 (1 nmol side(-1)) and CTOP (0.1 nmol side(-1)) into the nucleus accumbens.
resultsMicroinjection of SCH 23390, raclopride or CTOP into the nucleus accumbens produced dose-dependent decreases in breakpoints under the PR schedule, while naltrindole was without effect. The highest dose of SCH 23390 also significantly reduced locomotor activity measured during speedball self-administration. The combination of SCH 23390 and CTOP significantly reduced breakpoints, while not affecting locomotor activity.
conclusionsThese results indicate that dopamine and mu-opiate receptors, but not delta-opiate receptors, in the nucleus accumbens are involved in the reinforcing effects of speedball. Combined administration of D1 and mu-opiate receptor antagonists may be more selective at reducing the reinforcing effects of speedball self-administration than either drug alone.
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