Brebner K, Phelan R, Roberts D C
Institute of Neuroscience, Carleton University, Ottawa, ON, K1S 5B6, Canada.
Pharmacol Biochem Behav. 2000 Aug;66(4):857-62. doi: 10.1016/s0091-3057(00)00286-0.
The effect of microinjections of baclofen into the ventral tegmental area (VTA), nucleus accumbens, or striatum on cocaine self-administration reinforced on a progressive ratio schedule was investigated. Intra-VTA baclofen produced the most potent modulation of cocaine intake, causing a significant reduction in cocaine-reinforced break points at a dose (56 ng/side) that was substantially lower than doses necessary to produce comparable reductions in the nucleus accumbens or striatum. During the time that cocaine-reinforced responding was suppressed, rats demonstrated the capacity to complete several hundred responses on a concurrently available food-reinforced lever, indicating that the effect of baclofen on cocaine intake was not due to a generalized disruption in operant responding. The results indicate that GABA(B) receptors in the VTA may have the potential to modulate reward processes associated with cocaine use.
研究了向腹侧被盖区（VTA）、伏隔核或纹状体内微量注射巴氯芬对按累进比率程序强化的可卡因自我给药的影响。VTA内注射巴氯芬对可卡因摄入量产生了最有效的调节作用，在剂量（56 ng/侧）显著低于在伏隔核或纹状体内产生类似减少所需剂量时，就导致可卡因强化的断点显著降低。在可卡因强化反应受到抑制的期间，大鼠表现出能够在同时可用的食物强化杠杆上完成数百次反应的能力，这表明巴氯芬对可卡因摄入量的影响并非由于操作性反应的普遍破坏。结果表明，VTA中的GABA(B)受体可能具有调节与可卡因使用相关的奖赏过程的潜力。
