Welzl H, Kuhn G, Huston J P
Institute of Physiological Psychology, University of Düsseldorf, Federal Republic Germany.
Neuropharmacology. 1989 Oct;28(10):1017-23. doi: 10.1016/0028-3908(89)90112-3.
A micropipette-system was used to investigate intracranial self-injection of morphine in the rat. The system consisted of a glass micropipette (tip dia 5 microns) connected by flexible tubing and a swivel to a pressure source. Using nose-poking through a hole in one wall of the cage as the operant, rats self-injected quantities as small as 50 ng/5 nl of morphine into the ventral tegmental area. In contrast, rats in the saline-treated group and yoked-control group did not increase their rates of nose-poking behaviour above baseline levels. Intermittent reinforcement in the morphine-treated group resulted in a further increase in the rate of nose-poking. Histological inspection of the site of injection revealed minimal damage to brain tissue and likely confinement of the injected solution to the area around the tip of the pipette.
使用微量移液器系统研究大鼠颅内自我注射吗啡的情况。该系统由一根玻璃微量移液器（尖端直径5微米）组成，通过柔性 tubing 和一个旋转接头连接到压力源。以通过笼子一侧壁上的孔戳鼻子作为操作行为，大鼠将低至50纳克/5纳升的吗啡自我注射到腹侧被盖区。相比之下，生理盐水处理组和配对对照组的大鼠戳鼻子行为的频率并未高于基线水平。吗啡处理组的间歇性强化导致戳鼻子频率进一步增加。对注射部位的组织学检查显示对脑组织的损伤极小，并且注入的溶液可能局限于移液器尖端周围的区域。
