Maldonado-Irizarry C S, Stellar J R, Kelley A E
Department of Psychology, Northeastern University, Boston, MA 02115.
Pharmacol Biochem Behav. 1994 Aug;48(4):915-20. doi: 10.1016/0091-3057(94)90200-3.
Cocaine and GBR-12909, two dopamine reuptake blockers, were administered in a multiple current rate-frequency curve-shift test of intracranial self-stimulation (ICSS) reward in rats with medial forebrain bundle (MFB) electrodes. Acute injections of cocaine (0, 5, 15, 30 mg/kg, IP) increased ICSS reward at all currents (501, 316, 200 microAmps) as measured by decrease half-maximal frequency threshold. Cocaine also increased operant motor performance but only at the low current. In addition, cocaine increased dynamic interval at the highest dose at all currents. Similar treatment with GBR-12909 (0, 5, 10, 20 mg/kg, IP) significantly increased ICSS reward (decreased threshold) especially at the medium dose in all currents and had no significant effects on operant motor performance or dynamic interval. The major novel finding of the present study is that the rewarding effects of both drugs was not dependent on the choice of stimulation current, which is discussed as simplifying future psychophysical testing of psychostimulant drugs in the ICSS rate-frequency curve-shift paradigm.
在采用内侧前脑束（MFB）电极对大鼠进行颅内自我刺激（ICSS）奖赏的多电流频率曲线偏移测试中，给予可卡因和GBR - 12909这两种多巴胺再摄取阻滞剂。通过降低半数最大频率阈值来衡量，急性注射可卡因（0、5、15、30毫克/千克，腹腔注射）在所有电流（501、316、200微安）下均增加了ICSS奖赏。可卡因还增加了操作性运动表现，但仅在低电流时。此外，可卡因在所有电流下的最高剂量时增加了动态间隔。用GBR - 12909（0、5、10、20毫克/千克，腹腔注射）进行类似处理显著增加了ICSS奖赏（降低阈值），尤其是在所有电流下的中等剂量时，并且对操作性运动表现或动态间隔没有显著影响。本研究的主要新发现是，两种药物的奖赏作用不依赖于刺激电流的选择，这一点在ICSS频率曲线偏移范式中被认为简化了未来对精神兴奋剂药物的心理物理学测试。
