Winter J C, Timineri D
Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, 14214-3000, USA.
Pharmacol Biochem Behav. 1999 Mar;62(3):543-7. doi: 10.1016/s0091-3057(98)00190-7.
Stimulus control was established in a group of nine rats using a dose of EGb 761 of 10 mg/kg, administered i.p., 15 min before training. A two-lever operant task using a fixed-ratio 10 schedule of sweetened milk reinforcement was used. Based upon a criterion for the presence of stimulus control of five consecutive sessions during which 83% or more of all responses were on the appropriate lever, a mean of 24 sessions was required to reach criterion performance. Subsequently, it was observed that EGb 761-induced stimulus control is significantly antagonized by the selective 5-HT1A antagonist WAY-100635, but is unaffected by the 5-HT2 antagonist pirenperone. Furthermore, EGb 761 generalized to the selective 5-HT1A agonist, 8-hydroxy-dipropylaminotetralin [8-OH-DPAT], and this generalization was blocked by WAY-100635. The present results indicate that EGb 761 is able to induce stimulus control when administered via the intraperitoneal route, and that its stimulus effects are mediated in part by activity at the 5-HT1A receptor.
在一组9只大鼠中建立刺激控制，在训练前15分钟腹腔注射10mg/kg剂量的EGb 761。采用固定比率10的甜牛奶强化的双杠杆操作性任务。基于连续五个实验阶段存在刺激控制的标准，即所有反应的83%或更多发生在适当杠杆上，达到标准表现平均需要24个实验阶段。随后观察到，EGb 761诱导的刺激控制被选择性5-HT1A拮抗剂WAY-100635显著拮抗，但不受5-HT2拮抗剂匹仑哌隆的影响。此外，EGb 761能推广到选择性5-HT1A激动剂8-羟基-二丙基氨基四氢萘[8-OH-DPAT]，且这种推广被WAY-100635阻断。目前的结果表明，EGb 761经腹腔注射给药时能够诱导刺激控制，其刺激作用部分是由5-HT1A受体的活性介导的。
