Morphine-dopamine interaction: Ventral tegmental morphine increases nucleus accumbens dopamine release

Leone, Paola; Pocock, Dorothy M.-E.; Wise, Roy A.

doi:10.1016/0091-3057(91)90210-s

Cited by 200 publications

(103 citation statements)

References 23 publications

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“…132 Acute administration of morphine directly into the VTA induces release of DA in the NAc as measured by microdialysis in rats. 133 This coincides with increased firing of dopaminergic neurons in the VTA with acute IV morphine. 134 Naloxone reversed this effect.…”

Section: Molecular Changes In the Ventral Tegmental Areamentioning

confidence: 68%

Molecular Changes in Opioid Addiction: The Role of Adenylyl Cyclase and cAMP/PKA System

Chan

Lutfy

2016

Progress in Molecular Biology and Translational Science

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Section: Molecular Changes In the Ventral Tegmental Areamentioning

confidence: 68%

Molecular Changes in Opioid Addiction: The Role of Adenylyl Cyclase and cAMP/PKA System

Chan

Lutfy

2016

Progress in Molecular Biology and Translational Science

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“…The POMc projections arising from the ventrolateral part of the ArcN project to the VTA and the NAcb (Chronwall, 1985), and have been suggested to control basal DA release in the NAcb (Spanagel et al, 1992). The release of DA in the NAcb seems to be evoked indirectly by the activation of mu opioid receptors located on VTA GABAergic interneurons (Leone et al, 1991;Longoni et al, 1991;Spanagel et al, 1992). This neurochemical pathway has also been proposed to explain ethanol-induced increases in DA release in the NAcb, as opioid receptor antagonists prevented ethanol-induced activation of VTA DA neurons (Gonzales and Weiss, 1998;Tanda and Di Chiara, 1998).…”

Section: Discussionmentioning

confidence: 99%

The Role of Opioid Receptor Subtypes in the Development of Behavioral Sensitization to Ethanol

Pastor

Aragón

2005

Neuropsychopharmacol

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Nonspecific blockade of opioid receptors has been found to prevent development of behavioral sensitization to ethanol. Whether this effect is achieved through a specific opioid receptor subtype, however, is not clear. The present study investigated, for the first time, the role of specific opioid receptor subtypes in the development of ethanol-(2.5 g/kg/day; six sessions) induced locomotor sensitization in mice. We confirmed previous results showing that the nonspecific antagonism of opioid receptors (naltrexone; 0-2 mg/kg) prevented the development of behavioral sensitization to ethanol, an effect attained at doses presumed to occupy only mu opioid receptors. This was confirmed by using the selective mu opioid receptor antagonist CTOP (0-1.5 mg/kg), which also blocked sensitization to ethanol. The selective delta receptor antagonist, naltrindole (0-10 mg/kg), however, did not alter sensitization. We further assessed the role of mu opioid receptors in sensitization to ethanol by exploring the involvement of mu 1 , mu 1 + 2 , and mu 3 opioid receptor subtypes. Results of these experiments revealed that the blockade of mu 1 (naloxonazine; 0-30 mg/kg) or mu 3 opioid receptors (3-methoxynaltrexone; 0-6 mg/kg) did not prevent locomotor sensitization to ethanol. Using naloxonazine under treatment conditions that block mu 1 + 2 opioid receptor subtypes we observed a retarded sensitization. The present data suggest that the concurrent inactivation of all mu opioid receptor subtypes may be required to prevent the neural adaptations underlying the development of behavioral sensitization to ethanol. In addition, these results support previous data suggesting a putative role for the mu opioid receptor endogenous ligand, b-endorphin, and the hypothalamic arcuate nucleus in ethanol sensitization.

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“…These findings are in agreement with previous observations that MOR in the VTA are not located on DA neurons (Garzon and Pickel, 2001), suggesting an indirect relationship. Furthermore, pharmacological studies have shown that MOR agonists inhibit GABA neuron firing, stimulate DA neuron firing, and increase DA release into the NAc (Matthews and German, 1984;Leone et al, 1991;Johnson and North, 1992). In the current study, analysis of matinginduced internalization was restricted to the rostral portion of the VTA, where the majority of MOR-containing cell bodies are located.…”

Section: Discussionmentioning

confidence: 99%

Sexual Behavior and Sex-Associated Environmental Cues Activate the Mesolimbic System in Male Rats

Balfour

Coolen

2003

Neuropsychopharmacol

165

125

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The mesolimbic system plays an important role in the regulation of both pathological behaviors such as drug addiction and normal motivated behaviors such as sexual behavior. The present study investigated the mechanism by which this system is endogenously activated during sexual behavior. Specifically, the effects of sexual experience and sex-related environmental cues on the activation of several components of the mesolimbic system were studied. The mesolimbic system consists of a dopaminergic projection from the ventral tegmental area (VTA) to the nucleus accumbens (NAc). Previous studies suggest that these neurons are under tonic inhibition by local GABA interneurons, which are in turn modulated by mu opioid receptor (MOR) ligands. To test the hypothesis that opioids are acting in the VTA during sexual behavior, visualization of MOR internalization in VTA was used as a marker for ligand-induced activation of the receptor. Significant increases in MOR internalization were observed following copulation or exposure to sex-related environmental cues. The next goal was to determine if sexual behavior activates dopamine neurons in the VTA, using tyrosine hydroxylase as a marker for dopaminergic neurons and Fos-immunoreactivity as a marker for neuronal activation. Significant increases in the percentage of activated dopaminergic neurons were observed following copulation or exposure to sex-related environmental cues. In addition, mating and sex-related cues activated a large population of nondopaminergic neurons in VTA as well as neurons in both the NAc Core and Shell. Taken together, our results provide functional neuroanatomical evidence that the mesolimbic system is activated by both sexual behavior and exposure to sex-related environmental cues.

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Morphine-dopamine interaction: Ventral tegmental morphine increases nucleus accumbens dopamine release

Cited by 200 publications

References 23 publications

Molecular Changes in Opioid Addiction: The Role of Adenylyl Cyclase and cAMP/PKA System

Molecular Changes in Opioid Addiction: The Role of Adenylyl Cyclase and cAMP/PKA System

The Role of Opioid Receptor Subtypes in the Development of Behavioral Sensitization to Ethanol

Sexual Behavior and Sex-Associated Environmental Cues Activate the Mesolimbic System in Male Rats

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