The peripheral dopamine 2 receptor antagonist domperidone attenuates ethanol enhancement of dopamine levels in the nucleus accumbens. (1st February 2022)

• Record Type: Journal Article
• Authors: Obray, James Daniel; Jang, Eun Young; Klomp, Anneke M.; Small, Christina A.; Richardson, Aaron P.; LeBaron, Joshua J.; Lee, Jin Gyeom; Yorgason, Jordan T.; Yang, Chae Ha; Steffensen, Scott C.
• Is Part Of: Alcoholism. Volume 46:Number 3(2022)
• Page Start: 396
• Page End: 409
• Publication Date: 2022-02-01
• Subjects: domperidone -- dopamine -- dopamine 2 receptor -- ethanol -- microdialysis; Alcoholism -- Periodicals; Alcoholism -- Periodicals; Alcoolisme; Electronic journals; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 616.861005
• DOI: 10.1111/acer.14775
• Languages: English
• ISSNs: 0145-6008

Abstract

Abstract: Background: Dopamine neuron firing in the ventral tegmental area (VTA) and dopamine release in the nucleus accumbens have been implicated in reward learning. Ethanol is known to increase both dopamine neuron firing in the VTA and dopamine levels in the nucleus accumbens. Despite this, some discrepancies exist between the dose of ethanol required to enhance firing in vivo and ex vivo . In the present study we investigated the effects of peripheral dopamine 2 subtype receptor antagonism on ethanol's effects on dopamine neurotransmission. Methods: Plasma catecholamine levels were assessed following ethanol administration across four different doses of EtOH. Microdialysis and voltammetry were used to assess the effects of domperidone pretreatment on ethanol‐mediated increases in dopamine release in the nucleus accumbens. A place conditioning paradigm was used to assess conditioned preference for ethanol and whether domperidone pretreatment altered this preference. Open‐field and loss‐of‐righting reflex paradigms were used to assess the effects of domperidone on ethanol‐induced sedation. A rotarod apparatus was used to assess the effects of domperidone on ethanol‐induced motor impairment. Results: Domperidone attenuated ethanol's enhancement of mesolimbic dopamine release under non‐physiological conditions at intermediate (1.0 and 2.0 g/kg) doses of ethanol. Domperidone also decreased EtOH‐induced sedation at 2.0 g/kg. Domperidone did not alter ethanol conditioned place preference nor did it affect ethanol‐induced motor impairment. Conclusions: These results show that peripheral dopamine 2 receptors mediate some of the effects of ethanol on nonphysiological dopamine neurotransmission, although these effects are not related to the rewarding properties of ethanol. Abstract : We found that antagonism of peripheral dopamine 2 receptors using domperidone attenuated ethanol induced dopamine release in the nucleus accumbens following an acute dose of ethanol. Domperidone also reduced the sedating effects of a moderate dose of ethanol (2 g/kg, ip). These findings provide evidence that peripheral dopamine 2 receptors are involved in mediating some of the effects of ethanol on dopamine neurotransmission, although these effects are not related to the rewarding properties of ethanol.