The anti-relapse compound acamprosate inhibits the development of a conditioned place preference to ethanol and cocaine but not morphine

Abstract

The effects of the anti-relapse compound acamprosate (calcium acetylhomotaurinate) on the conditioned rewarding effects of ethanol, cocaine and morphine were studied using the conditioned place preference (CPP) paradigm. During 3 days of drug conditioning, mice were pretreated with saline or acamprosate (30, 100 or 300 mg kg(-1) i.p.) 10 min prior to the administration of ethanol (2 g kg(-1) i.p.), cocaine (15 mg kg(-1) i.p.) or morphine (10 mg kg(-1) i.p.), and subsequently confined to one of two distinct conditioning chambers. On the following day, mice were tested for the expression of CPP. Acamprosate dose-dependently reduced the development of CPP to ethanol and cocaine but not morphine. When tested as the conditioning drug, acamprosate alone produced neither a conditioned place preference nor aversion. These data suggest that acamprosate can suppress the conditioned rewarding effects of ethanol and certain classes of abused substances.

Figure 1

Effect of acamprosate on CPP produced by ethanol (A, 2 g kg⁻¹), cocaine (B, 15 mg kg⁻¹) and morphine (C, 10 mg kg⁻¹). Mouse strains used for each CPP procedure are given in each panel. Acamprosate was given i.p. 10 min prior to the administration of the conditioning drug. (D) Absence of CPP or aversion when acamprosate alone was used as the conditioning drug in C57BL/6J or DBA/2J mice. Data are presented as mean±s.e. ^*P<0.05 vs saline pretreated group. n=8–12 for all groups.