Faculty Opinions recommendation of The active heroin metabolite 6-acetylmorphine has robust reinforcing effects as assessed by self-administration in the rat.

Recent estimates suggest increased popularity of the concurrent use of opioids and stimulants, with over 50% of treatment-seeking opioid users reporting regular stimulant use. The goal of the current study was to determine how opioid dependence and withdrawal affect the reinforcing effects of fentanyl, cocaine, and methamphetamine. Male Sprague-Dawley rats were allowed to self-administer fentanyl under a progressive ratio (PR) schedule of reinforcement. Baseline evaluations of reinforcing effectiveness of fentanyl, cocaine, and methamphetamine were determined. Opioid dependence was then established by administering escalating doses of morphine (10–40 mg/kg) twice-daily for four days and subsequently maintained by once-daily injections of 40 mg/kg morphine. To evaluate the impact of opioid dependence and withdrawal on the self-administration of fentanyl, cocaine, and methamphetamine, sessions occurred either 12 or 20 h after the morphine, respectively. During opioid withdrawal, the fentanyl dose-response curve was shifted rightward with an increase in maximal effectiveness, whereas it was shifted rightward with a reduction in maximal effectiveness when evaluated in rats currently dependent on opioids, relative to baseline. The reinforcing effects of cocaine and methamphetamine were unchanged by either condition. The current studies provide direct evidence that the reinforcing effects of fentanyl are increased in opioid-withdrawn rats and reduced in opioid-dependent rats, relative to rats that are not physically dependent on opioids. These findings suggest that motivations to use opioids are dependent on the state of the individual whereas stimulants retain their reinforcing effects regardless of whether the individual is in an opioid-dependent or withdrawn state.

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Discrete-trials heroin self-administration produces sensitization to the reinforcing effects of cocaine in rats

Psychopharmacology ◽

10.1007/s00213-005-0288-9 ◽

2006 ◽

Vol 185 (2) ◽

pp. 150-159 ◽

Cited By ~ 16

Author(s):

Sara J. Ward ◽

Christopher Läck ◽

Drake Morgan ◽

David C. S. Roberts

Keyword(s):

Self Administration ◽

Discrete Trials ◽

Reinforcing Effects

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The Cannabinoid CB1 Antagonist N-Piperidinyl-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl) -4-methylpyrazole-3-carboxamide (SR-141716A) Differentially Alters the Reinforcing Effects of Heroin under Continuous Reinforcement, Fixed Ratio, and Progressive Ratio Schedules of Drug Self-Administration in Rats

Journal of Pharmacology and Experimental Therapeutics ◽

10.1124/jpet.102.047928 ◽

2003 ◽

Vol 306 (1) ◽

pp. 93-102 ◽

Cited By ~ 113

Author(s):

M. Solinas ◽

L. V. Panlilio ◽

K. Antoniou ◽

L. A. Pappas ◽

S. R. Goldberg

Keyword(s):

Fixed Ratio ◽

Progressive Ratio ◽

Self Administration ◽

Continuous Reinforcement ◽

Sr 141716A ◽

Cb1 Antagonist ◽

Reinforcing Effects

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Oral self-administration of pentobarbital by rhesus monkeys: relative reinforcing effects under concurrent signalled differential-reinforcement-of-low-rates schedules

Drug and Alcohol Dependence ◽

10.1016/0376-8716(92)90055-h ◽

1992 ◽

Vol 30 (3) ◽

pp. 215-225 ◽

Cited By ~ 14

Author(s):

Richard A. Meisch ◽

Gregory A. Lemaire ◽

Edward B. Cutrell

Keyword(s):

Rhesus Monkeys ◽

Differential Reinforcement ◽

Self Administration ◽

Reinforcing Effects

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Methylphenidate self-administration increases the potency and reinforcing effects of releasers through a dopamine transporter mechanism

Drug and Alcohol Dependence ◽

10.1016/j.drugalcdep.2014.02.088 ◽

2014 ◽

Vol 140 ◽

pp. e24-e25

Author(s):

Erin Calipari ◽

M.J. Ferris ◽

A. Salahpour ◽

M.G. Caron ◽

D.C. Roberts ◽

...

Keyword(s):

Dopamine Transporter ◽

Self Administration ◽

Reinforcing Effects

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Evidence for a vocal signature in the rat and its reinforcing effects: a key role for the subthalamic nucleus

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2021.2260 ◽

2021 ◽

Vol 288 (1965) ◽

Author(s):

Cassandre Vielle ◽

Christian Montanari ◽

Yann Pelloux ◽

Christelle Baunez

Keyword(s):

Subthalamic Nucleus ◽

Social Factors ◽

Lever Press ◽

Emotional Valence ◽

Ultrasonic Vocalizations ◽

Drug Consumption ◽

Self Administration ◽

Vocal Signature ◽

Reinforcing Effects

Although rodents have a well-structured vocal form of communication, like humans and non-human primates, there is, to date, no evidence for a vocal signature in the well-known 50- and 22-kHz ultrasonic vocalizations (USVs) emitted by rats. Here, we show that rats can recognize the identity of the USV emitter since they choose to preferentially self-administer playback of 50-kHz USVs emitted by a stranger rat over those of their cagemate. In a second experiment, we show that only stranger, but not familiar, 50-kHz USVs reduce cocaine self-administration. Finally, to study the neurobiological substrate of these processes, we have shown that subthalamic nucleus (STN)-lesioned rats did not lever press much for any USV playback, whatever their emotional valence, nor did they seem able to differentiate familiar from stranger peer. Advocating for the existence of a vocal signature in rats, these results highlight the importance of ultrasonic communication in the socio-affective influence of behaviour, such as the influence of proximal social factors on drug consumption and confirm the role of the STN on this influence.

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