TY - JOUR
T1 - The effects of naloxone on expression and acquisition of ethanol place conditioning in rats
AU - Bormann, Nancy M.
AU - Cunningham, Christopher L.
N1 - Funding Information:
This research was supported in part by NIAAA Grants AA07702 and AA07468. Portions of these data were presented at the annual meeting of the Research Society on Alcoholism (Washington, D.C., June 1996).
PY - 1997/12
Y1 - 1997/12
N2 - Naloxone has been shown to facilitate extinction of ethanol-induced conditioned place preference (CPP) in mice. The present study extended these findings by examining naloxone's effect on the expression (Experiment 1) and acquisition (Experiment 2) of place conditioning with ethanol in rats. In Experiment 1, alter place conditioning with ethanol (1.8 g/kg, IP), groups N0, N1.5, and N10 received 0, 1.5, or 10 mg/kg naloxone before testing. As expected, ethanol produced a robust conditioned place aversion (CPA). However, naloxone had no effect on expression of CPA. In contrast to studies with mice, the endogenous opioid system does not appear to be involved in the conditioned motivational effects of ethanol in rats. In Experiment 2, groups SE1 and SE2, NS(1.5), NE(1.5), and NE(10), received ethanol alone (1.2 g/kg), naloxone alone (1.5 mg/kg), naloxone 1.5 mg/kg plus ethanol, and naloxone 10 mg/kg plus ethanol during acquisition, respectively. All naloxone-treated groups exhibited CPA. Moreover, group NE(1.5) showed a stronger CPA than group NS(1.5). The CPA produced by coadministration of naloxone and ethanol was attributed to naloxone's effects on the neural processes underlying ethanol's unconditioned aversive effects, or to other nonspecific effects on ethanol's motivational properties.
AB - Naloxone has been shown to facilitate extinction of ethanol-induced conditioned place preference (CPP) in mice. The present study extended these findings by examining naloxone's effect on the expression (Experiment 1) and acquisition (Experiment 2) of place conditioning with ethanol in rats. In Experiment 1, alter place conditioning with ethanol (1.8 g/kg, IP), groups N0, N1.5, and N10 received 0, 1.5, or 10 mg/kg naloxone before testing. As expected, ethanol produced a robust conditioned place aversion (CPA). However, naloxone had no effect on expression of CPA. In contrast to studies with mice, the endogenous opioid system does not appear to be involved in the conditioned motivational effects of ethanol in rats. In Experiment 2, groups SE1 and SE2, NS(1.5), NE(1.5), and NE(10), received ethanol alone (1.2 g/kg), naloxone alone (1.5 mg/kg), naloxone 1.5 mg/kg plus ethanol, and naloxone 10 mg/kg plus ethanol during acquisition, respectively. All naloxone-treated groups exhibited CPA. Moreover, group NE(1.5) showed a stronger CPA than group NS(1.5). The CPA produced by coadministration of naloxone and ethanol was attributed to naloxone's effects on the neural processes underlying ethanol's unconditioned aversive effects, or to other nonspecific effects on ethanol's motivational properties.
KW - Aversion
KW - Conditioned place aversion
KW - Ethanol
KW - Locomotor activity
KW - Naloxone
KW - Opioid antagonist
KW - Place conditioning
KW - Rats
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U2 - 10.1016/S0091-3057(97)00304-3
DO - 10.1016/S0091-3057(97)00304-3
M3 - Article
C2 - 9408203
AN - SCOPUS:0031406537
SN - 0091-3057
VL - 58
SP - 975
EP - 982
JO - Pharmacology Biochemistry and Behavior
JF - Pharmacology Biochemistry and Behavior
IS - 4
ER -