Lack of effect of dopamine receptor blockade on expression of ethanol-induced conditioned place preference in mice.
BACKGROUND
Self-administration studies have suggested that dopamine (DA) is important for the reinforcing effects of ethanol. However, ethanol place conditioning studies have less consistently demonstrated a role for DA in conditioned place preference.


OBJECTIVE
The purpose of the present study was to determine whether blockade of D(1), D(2) or D(3) DA receptors would impact the expression of the conditioned place preference induced by ethanol in DBA/2J mice.


METHODS
Mice underwent an unbiased place conditioning procedure with 2 g/kg ethanol. Prior to the preference test, mice were injected i.p. with SCH23390 (0, 0.015 or 0.03 mg/kg), raclopride (0, 0.3 or 0.6 mg/kg) or U99194A (0, 10 or 20 mg/kg).


RESULTS
Ethanol produced a significant conditioned place preference that was not affected by any of the dopamine antagonists tested. Each of the antagonists decreased locomotor activity, though U99194A was minimally effective.


CONCLUSIONS
These findings suggest that the conditioned reinforcing effects of ethanol in DBA/2J mice as assessed by place conditioning are mediated by non-dopaminergic mechanisms.
Dickinson
Shelly D
SD
Psychology Department, Amherst College, P.O. Box 5000, Amherst, MA 01002-5000, USA. sddickinson@amherst.edu
Lee
Elizabeth L
EL
Rindal
Kirsten
K
Cunningham
Christopher L
CL
D000818:Animals; D001245:Association Learning / Q000187:drug effects; D001552:Benzazepines / Q000494:pharmacology; D003214:Conditioning, Classical / Q000187:drug effects*; D018492:Dopamine Antagonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology*; D007189:Indans / Q000494:pharmacology; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D009042:Motivation; D009043:Motor Activity / Q000187:drug effects*; D020891:Raclopride / Q000494:pharmacology; D011954:Receptors, Dopamine / Q000187:drug effects* / Q000502:physiology
D001552:Benzazepines; D018492:Dopamine Antagonists; D007189:Indans; D011954:Receptors, Dopamine; C086335:(5,6-dimethoxyindan-2-yl)dipropylamine; D000431:Ethanol; D020891:Raclopride