Orexin type-2 receptor blockade prevents the nicotine-induced excitation of nucleus accumbens core neurons in rats: An electrophysiological perspective.
Nicotine
Nucleus accumbens core
Orexin system
Single unit recording
TCS-OX2-29
Journal
Pharmacological reports : PR
ISSN: 2299-5684
Titre abrégé: Pharmacol Rep
Pays: Switzerland
ID NLM: 101234999
Informations de publication
Date de publication:
Apr 2019
Apr 2019
Historique:
received:
07
07
2018
revised:
11
12
2018
accepted:
29
12
2018
pubmed:
5
3
2019
medline:
18
6
2019
entrez:
5
3
2019
Statut:
ppublish
Résumé
The nucleus accumbens core (NAcc) expresses both orexin and nicotinic acetylcholine receptors (nAChRs). Orexin is among important neurotransmitters, which regulates addictive properties of drugs of abuse including nicotine. The role of orexin-2 receptor (OX2R) in the regulation of NAcc neural activity in response to nicotine has not yet been studied. Hence, in this study, we examined whether the OX2R antagonist (TCS-OX2-29) can adjust the effects of nicotine on electrical activity of NAcc neurons, in urethane-anesthetized rats, using the single unit recording. Neuronal firing of NAcc was recorded for 15 min, then TCS-OX2-29 (OX2R-antagonist; 1, 3 and 10 ng/rat) or DMSO were microinjected into NAcc, just 5 min before subcutaneous (sc) administration of nicotine (0.5 mg/kg) or saline. The spontaneous firing activity was recorded for 70 min, after nicotine injection. The results demonstrated that nicotine significantly excites the NAcc neurons and interestingly, the administration of TCS-OX2-29 (3 and 10 ng/rat) into the NAcc, inhibited nicotine-induced increases of NAcc neuronal responses. Furthermore, administration of TCS-OX2-29 (10 ng/rat), just 5 min before sc administration of saline instead of nicotine, did not significantly alter the neuronal responses, compared to the saline-control group. Our results showed that, although OX2R blockade alone did not affect neuronal activity in the NAcc, it was able to prevent the exciting effects of nicotine on NAcc neuronal activity. Therefore, we proposed that orexin has a potential modulator effect, in response to nicotine.
Sections du résumé
BACKGROUND
BACKGROUND
The nucleus accumbens core (NAcc) expresses both orexin and nicotinic acetylcholine receptors (nAChRs). Orexin is among important neurotransmitters, which regulates addictive properties of drugs of abuse including nicotine. The role of orexin-2 receptor (OX2R) in the regulation of NAcc neural activity in response to nicotine has not yet been studied. Hence, in this study, we examined whether the OX2R antagonist (TCS-OX2-29) can adjust the effects of nicotine on electrical activity of NAcc neurons, in urethane-anesthetized rats, using the single unit recording.
METHODS
METHODS
Neuronal firing of NAcc was recorded for 15 min, then TCS-OX2-29 (OX2R-antagonist; 1, 3 and 10 ng/rat) or DMSO were microinjected into NAcc, just 5 min before subcutaneous (sc) administration of nicotine (0.5 mg/kg) or saline. The spontaneous firing activity was recorded for 70 min, after nicotine injection.
RESULTS
RESULTS
The results demonstrated that nicotine significantly excites the NAcc neurons and interestingly, the administration of TCS-OX2-29 (3 and 10 ng/rat) into the NAcc, inhibited nicotine-induced increases of NAcc neuronal responses. Furthermore, administration of TCS-OX2-29 (10 ng/rat), just 5 min before sc administration of saline instead of nicotine, did not significantly alter the neuronal responses, compared to the saline-control group.
CONCLUSION
CONCLUSIONS
Our results showed that, although OX2R blockade alone did not affect neuronal activity in the NAcc, it was able to prevent the exciting effects of nicotine on NAcc neuronal activity. Therefore, we proposed that orexin has a potential modulator effect, in response to nicotine.
Identifiants
pubmed: 30831442
pii: S1734-1140(18)30413-4
doi: 10.1016/j.pharep.2018.12.013
pii:
doi:
Substances chimiques
1-(3,4-dihydro-6,7-dimethoxy-2(1H)-isoquinolinyl)-3,3-dimethyl-2-((4-pyridinylmethyl)amino)-1-butanone
0
Isoquinolines
0
Orexin Receptor Antagonists
0
Orexin Receptors
0
Orexins
0
Pyridines
0
Nicotine
6M3C89ZY6R
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
361-366Informations de copyright
Copyright © 2018 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier B.V. All rights reserved.