Tags

Type your tag names separated by a space and hit enter

Involvement of dopamine D2 autoreceptors in the ventral tegmental area on alcohol and saccharin intake of the alcohol-preferring P rat.
Alcohol Clin Exp Res. 2000 Apr; 24(4):476-83.AC

Abstract

BACKGROUND

The ventral tegmental area (VTA) dopamine (DA) system is considered to be involved in mediating the actions of ethanol (EtOH). The objective of the present study was to examine the role of VTA DA D2 receptors in regulating EtOH intake of alcohol-preferring P rats.

METHODS

EtOH (10% v/v) and saccharin (SACC, 0.0125% g/v) intake during 2 hr of limited access was assessed after microinjections of the D2 agonist quinpirole and the D2 antagonist sulpiride into the anterior VTA (AVTA) of female P rats. Both EtOH-SACC alternate-day-access conditions and daily availability of EtOH and SACC solutions to separate groups of subjects were used. A second D2 agonist, quinelorane, and coadministration of 2.0 microg sulpiride with 2.0 microg quinpirole were tested in animals given limited access to EtOH. Finally, the effects of quinpirole injected 2 mm dorsal to the VTA and within the posterior VTA (PVTA) were assessed under EtOH-SACC alternate-day-access conditions.

RESULTS

Microinjections of 2.0-6.0 microg quinpirole into the AVTA dose dependently decreased EtOH intake 40-80% during the first 30 min of the limited access sessions but did not alter SACC intake. Injections of 2.0-4.0 microg quinelorane into the AVTA also reduced EtOH intake in the first 30 min. Administration of 0.5-2.0 microg sulpiride into the AVTA had no effect on either EtOH or SACC intakes but did attenuate the effects of quinpirole on reducing EtOH intake. Injections of 2.0-4.0 quinpirole 2 mm dorsal to the VTA did not alter EtOH or SACC intakes. Posterior VTA injections of quinpirole decreased EtOH and SACC intakes approximately 25-30% and 60-70%, respectively, in the first 30 min. None of the treatments altered intakes during the 30-120 min period.

CONCLUSIONS

The data suggest that DA neuronal activity within the AVTA may be important for maintaining EtOH drinking in P rats, whereas DA neuronal activity within the PVTA may be involved in regulating general drinking and/or motivational behaviors. Overall, the results confirm the involvement of mesolimbic DA in EtOH self-administration and suggest that there is functional heterogeneity within the VTA regulating drinking behavior of the P rat.

Authors+Show Affiliations

Department of Psychiatry, Indiana University School of Medicine, Indianapolis, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

10798583

Citation

Nowak, K L., et al. "Involvement of Dopamine D2 Autoreceptors in the Ventral Tegmental Area On Alcohol and Saccharin Intake of the Alcohol-preferring P Rat." Alcoholism, Clinical and Experimental Research, vol. 24, no. 4, 2000, pp. 476-83.
Nowak KL, McBride WJ, Lumeng L, et al. Involvement of dopamine D2 autoreceptors in the ventral tegmental area on alcohol and saccharin intake of the alcohol-preferring P rat. Alcohol Clin Exp Res. 2000;24(4):476-83.
Nowak, K. L., McBride, W. J., Lumeng, L., Li, T. K., & Murphy, J. M. (2000). Involvement of dopamine D2 autoreceptors in the ventral tegmental area on alcohol and saccharin intake of the alcohol-preferring P rat. Alcoholism, Clinical and Experimental Research, 24(4), 476-83.
Nowak KL, et al. Involvement of Dopamine D2 Autoreceptors in the Ventral Tegmental Area On Alcohol and Saccharin Intake of the Alcohol-preferring P Rat. Alcohol Clin Exp Res. 2000;24(4):476-83. PubMed PMID: 10798583.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Involvement of dopamine D2 autoreceptors in the ventral tegmental area on alcohol and saccharin intake of the alcohol-preferring P rat. AU - Nowak,K L, AU - McBride,W J, AU - Lumeng,L, AU - Li,T K, AU - Murphy,J M, PY - 2000/5/8/pubmed PY - 2000/8/1/medline PY - 2000/5/8/entrez SP - 476 EP - 83 JF - Alcoholism, clinical and experimental research JO - Alcohol Clin Exp Res VL - 24 IS - 4 N2 - BACKGROUND: The ventral tegmental area (VTA) dopamine (DA) system is considered to be involved in mediating the actions of ethanol (EtOH). The objective of the present study was to examine the role of VTA DA D2 receptors in regulating EtOH intake of alcohol-preferring P rats. METHODS: EtOH (10% v/v) and saccharin (SACC, 0.0125% g/v) intake during 2 hr of limited access was assessed after microinjections of the D2 agonist quinpirole and the D2 antagonist sulpiride into the anterior VTA (AVTA) of female P rats. Both EtOH-SACC alternate-day-access conditions and daily availability of EtOH and SACC solutions to separate groups of subjects were used. A second D2 agonist, quinelorane, and coadministration of 2.0 microg sulpiride with 2.0 microg quinpirole were tested in animals given limited access to EtOH. Finally, the effects of quinpirole injected 2 mm dorsal to the VTA and within the posterior VTA (PVTA) were assessed under EtOH-SACC alternate-day-access conditions. RESULTS: Microinjections of 2.0-6.0 microg quinpirole into the AVTA dose dependently decreased EtOH intake 40-80% during the first 30 min of the limited access sessions but did not alter SACC intake. Injections of 2.0-4.0 microg quinelorane into the AVTA also reduced EtOH intake in the first 30 min. Administration of 0.5-2.0 microg sulpiride into the AVTA had no effect on either EtOH or SACC intakes but did attenuate the effects of quinpirole on reducing EtOH intake. Injections of 2.0-4.0 quinpirole 2 mm dorsal to the VTA did not alter EtOH or SACC intakes. Posterior VTA injections of quinpirole decreased EtOH and SACC intakes approximately 25-30% and 60-70%, respectively, in the first 30 min. None of the treatments altered intakes during the 30-120 min period. CONCLUSIONS: The data suggest that DA neuronal activity within the AVTA may be important for maintaining EtOH drinking in P rats, whereas DA neuronal activity within the PVTA may be involved in regulating general drinking and/or motivational behaviors. Overall, the results confirm the involvement of mesolimbic DA in EtOH self-administration and suggest that there is functional heterogeneity within the VTA regulating drinking behavior of the P rat. SN - 0145-6008 UR - https://www.unboundmedicine.com/medline/citation/10798583/Involvement_of_dopamine_D2_autoreceptors_in_the_ventral_tegmental_area_on_alcohol_and_saccharin_intake_of_the_alcohol_preferring_P_rat_ L2 - https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0145-6008&date=2000&volume=24&issue=4&spage=476 DB - PRIME DP - Unbound Medicine ER -