TY - JOUR
T1 - Factors affecting ethanol-induced conditioned place preference and locomotor sensitization in mice
AU - Shimizu, Chikako
AU - Oki, Yasuhiro
AU - Mitani, Yutaka
AU - Nakamura, Takeshi
AU - Nabeshima, Toshitaka
N1 - Publisher Copyright:
© 2015 The Pharmaceutical Society of Japan.
PY - 2015/12/1
Y1 - 2015/12/1
N2 - The rewarding effects of alcohol can lead to progressively heavier and more frequent drinking. Since studies of reward have mainly focused on responses to higher alcohol doses, the relations between reward and moderate/sustained alcohol exposure remain unknown. Our objective was to evaluate factors affecting the reward value of low alcohol doses and risk factors for increasing alcohol doses due to reward progression caused by alcohol exposure patterns. We thus performed conditioned place preference (CPP) and ethanol (EtOH)-induced locomotor sensitization tests in mice. Low-dose EtOH (0.5 or 1 g/kg twice/week)-induced CPP was stronger than that produced by saline control treatment, but the effect decreased with increasing numbers of conditioning trials. Moderate-dose/long-term EtOH exposure induced a weaker CPP than high-dose/short-term EtOH (2 g/kg twice/week) exposure with the same total EtOH dose (8 g/kg/experiment). Acamprosate calcium, an anti-relapse drug, preclusively reduced EtOH-induced CPP. EtOH induced CPP and locomotor sensitization in black but not white chamber, although the initial preference and the basal locomotion in each chamber were equal. Therefore the brightness of the chamber had an effect on EtOHinduced sensitization. Moreover, additional studies indicated that EtOH-induced locomotor sensitization also depends on the dose but not the administration interval. Paired associative learning with EtOH exposure is a potent factor influencing the level of reward produced by EtOH. Moreover, exposure to high doses of alcohol, even on an intermittent schedule, carries a higher risk of addiction than exposure to moderate doses over longer periods.
AB - The rewarding effects of alcohol can lead to progressively heavier and more frequent drinking. Since studies of reward have mainly focused on responses to higher alcohol doses, the relations between reward and moderate/sustained alcohol exposure remain unknown. Our objective was to evaluate factors affecting the reward value of low alcohol doses and risk factors for increasing alcohol doses due to reward progression caused by alcohol exposure patterns. We thus performed conditioned place preference (CPP) and ethanol (EtOH)-induced locomotor sensitization tests in mice. Low-dose EtOH (0.5 or 1 g/kg twice/week)-induced CPP was stronger than that produced by saline control treatment, but the effect decreased with increasing numbers of conditioning trials. Moderate-dose/long-term EtOH exposure induced a weaker CPP than high-dose/short-term EtOH (2 g/kg twice/week) exposure with the same total EtOH dose (8 g/kg/experiment). Acamprosate calcium, an anti-relapse drug, preclusively reduced EtOH-induced CPP. EtOH induced CPP and locomotor sensitization in black but not white chamber, although the initial preference and the basal locomotion in each chamber were equal. Therefore the brightness of the chamber had an effect on EtOHinduced sensitization. Moreover, additional studies indicated that EtOH-induced locomotor sensitization also depends on the dose but not the administration interval. Paired associative learning with EtOH exposure is a potent factor influencing the level of reward produced by EtOH. Moreover, exposure to high doses of alcohol, even on an intermittent schedule, carries a higher risk of addiction than exposure to moderate doses over longer periods.
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U2 - 10.1248/bpb.b15-00626
DO - 10.1248/bpb.b15-00626
M3 - Article
C2 - 26377735
AN - SCOPUS:84948691254
SN - 0918-6158
VL - 38
SP - 1935
EP - 1945
JO - Biological and Pharmaceutical Bulletin
JF - Biological and Pharmaceutical Bulletin
IS - 12
ER -