title: D-cycloserine, sarcosine and D-serine diminish the expression of cocaine-induced conditioned place preference.
abstract: Reactivation of cocaine-associated memories plays a critical role in reinstating the cocaine-seeking behavior and causing relapse. Cocaine-induced conditioned place preference (CPP) was used as a behavioral paradigm indicative of cocaine-associated memory and repeated cocaine-free preference tests served as a behavioral procedure to retrieve such a memory in this study. Since D-cycloserine was reported to eradicate drug-associated memories, two other N-methyl-D-aspartate (NMDA) receptor agonists were assessed for their efficacy on facilitating the extinction of cocaine-induced CPP. Although D-cycloserine (30 mg/kg) abolished cocaine (10 mg/kg)-induced CPP, sarcosine (300 and 600 mg/kg) and D-serine (600 mg/kg) diminished the expression of such a cocaine memory. Sarcosine (600 mg/kg) and D-serine (600 mg/kg) did not affect the storage of this cocaine memory. It was of interest to note that D-cycloserine facilitated the extinction of cocaine-induced CPP in a fast and early-onset manner, while sarcosine and D-serine decreased cocaine-induced CPP expression in a delay-onset manner. D-cycloserine (30 mg/kg), D-serine (600 mg/kg) and sarcosine (600 mg/kg) did not affect the consolidation of cocaine (5 mg/kg)-induced CPP. Finally, sarcosine (at 600 mg/kg/day for 3 consecutive days) and D-serine (at 600 mg/kg/day for 3 consecutive days) did not produce observable aversive effect associated with their administration in a conditioned place aversion paradigm. Likewise, a similar dosing regimen of sarcosine or D-serine did not cause evident activity-impairing effect. In addition to D-cycloserine treatment, our results indicate that long-term treatment with D-serine and sarcosine may afford a therapeutic advance in suppressing the expression of cocaine-associated memory.
authors.affiliation: Institute of Behavioral Medicine, National Cheng Kung University College of Medicine, Tainan, Republic of China.
authors.forename: Fu-Yung
authors.initials: FY
authors.lastname: Yang
authors.forename: Yung-Shuan
authors.initials: YS
authors.lastname: Lee
authors.forename: Chianfang G
authors.initials: CG
authors.lastname: Cherng
authors.forename: Ling-Yi
authors.initials: LY
authors.lastname: Cheng
authors.forename: Wan-Ting
authors.initials: WT
authors.lastname: Chang
authors.forename: Jia-Ying
authors.initials: JY
authors.lastname: Chuang
authors.forename: Gour-Shenq
authors.initials: GS
authors.lastname: Kao
authors.forename: Lung
authors.initials: L
authors.lastname: Yu
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003042:Cocaine / Q000494:pharmacology*; D003213:Conditioning, Psychological / Q000187:drug effects; D003523:Cycloserine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005108:Extinction, Psychological / Q000187:drug effects; D008297:Male; D008568:Memory / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D012521:Sarcosine / Q000008:administration & dosage / Q000494:pharmacology*; D012694:Serine / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D012694:Serine; D003523:Cycloserine; D003042:Cocaine; D012521:Sarcosine