Neuropeptide trefoil factor 3 increases reward effects of cocaine in rats / 中华行为医学与脑科学杂志

ABSTRACT

Objective To investigate the role of neuropeptide trefoil factor 3 (TFF3) in cocaine reward responses and the underlying mechanism.Methods Fifty SD rats were divided into 6 groups including Control group,Cocaine group,Cocaine + TFF3 (0.01 mg/kg) group,cocaine + TFF3 (0.1 mg/kg) group,cocaine + TFF3 (0.5 mg/kg) group and TFF3 (0.1 mg/kg) group,ip,n=7 ～ 9),and were treated with TFF3 / saline (ip),30 min later,rats were injected with cocaine (10 mg/kg ip) followed by 1 h hypedocomotion test.Immediately after behavioral test,rats (n=4～6) were decapitated and tissues of nucleus accumbens (NAc) were isolated and prepared for neurotransmitters analysis by HPLC; Another twenty one rats were divided into control and TFF3-treatment group,and the rats were trained with a modified 2-day cocaine CPP conditioning procedure.During cocaine CPP conditioning process,saline or TFF3 (0.1 mg/kg ip) was injected 30 min prior to cocaine injection (5 mg/kg ip).Results Systemic administration of TFF3 (0.1 mg/kg,ip) significantly increased the cocaine-induced locomotor activity (Total distance in 1 hour were (180±41) cm,(359±53) cm,(590±75) cm,(153±27) cm for Control,Vehicle + Cocaine,TFF3+Cocaine and TFF3+Vehicle groups respectively) and augmented cocaine rewarding effects in CPP(Post-training CPP score were (98± 18) s,(187±24) s for Vehicle + Cocaine,TFF3+Cocaine groups respectively).TFF3 (0.1 mg/kg ip) administration increased the dopamine concentration in the NAc induced by cocaine injection ((0.65±0.1) ng/ml,(1.24±0.14) ng/ml,(1.75±0.23) ng/ml,(0.74±0.21) ng/ml for Control,Cocaine,TFF3 + Cocaine and TFF3 + Vehicle groups respectively).Conclusion TFF3 is involved in regulation of behavioral response to cocaine,which is associated with the increasing of dopamine in the NAc.