PREEXPOSURE SENSITIZES RATS TO THE REWARDING EFFECTS OF COCAINE
PREEXPOSURE SENSITIZES RATS TO THE REWARDING EFFECTS OF COCAINE
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DOI：
10.1016/0091-3057(90)90552-s
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发表时间：
1990-12-01
影响因子：
3.6
通讯作者：
SCHENK, S
中科院分区：
文献类型：
--
作者：
HORGER, BA;SHELTON, K;SCHENK, S
在暴露前阶段，大鼠每天注射一次盐酸可卡因（10 mg/kg，IP）或生理盐水溶剂，连续12天。 在预处理阶段长期暴露于可卡因的大鼠对随后注射可卡因的运动激活作用的反应比用盐水长期治疗的大鼠更敏感。 在自我给药试验中，盐水预处理组相对于非活性杠杆未表现出对产生可卡因输注的杠杆的显著偏好，表明试验剂量（0.225和0.45 mg/kg/输注）为可卡因奖励的亚阈值。 相比之下，预先暴露于可卡因的受试者有更高的强化反应率，并表现出对导致可卡因输注的杠杆的偏好。 较高的应答率不太可能是由于非特异性活性升高，因为在9天的测试中，非活性杠杆应答保持较低且相对不变。 因此，可卡因预暴露大鼠的反应增强表明药物的强化效果增加了。 这些数据表明，可卡因的行为效应的敏感性可以提高，可卡因滥用的诱发因素可以操纵。
During a preexposure period rats were injected once daily with either cocaine HCl (10 mg/kg, IP) or the saline vehicle for 12 consecutive days. Rats that were chronically exposed to cocaine during the pretreatment phase were more responsive to the motor activating effects of a subsequent injection of cocaine than were rats chronically treated with saline. In self-administration testing, saline-pretreated groups did not exhibit a significant preference for a lever producing a cocaine infusion relative to an inactive lever, suggesting that doses tested (0.225 and 0.45 mg/kg/infusion) were subthreshold for cocaine reward. In contrast, subjects preexposed to cocaine had a higher rate of reinforced responses and exhibited a preference for a lever that resulted in a cocaine infusion. It was unlikely that the higher response rate was due to an elevation in nonspecific activity since inactive lever responding remained low and relatively invariant over the 9 days of testing. Thus the enhanced responding in the cocaine-preexposed rats suggests that the reinforcing effectiveness of the drug had increased. These data indicate that sensitivity to cocaine's behavioral effects can be enhanced and that predisposing factors to cocaine abuse can be manipulated.