Tatham T A, Gyorda A M, Barrett J E
Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, MD 20814.
Pharmacol Biochem Behav. 1994 Jun;48(2):491-5. doi: 10.1016/0091-3057(94)90558-4.
The effects of cocaine on punished and unpunished key peck responding of pigeons was examined before and after a history of treadle pressing maintained by shock postponement. In one schedule component, the first peck after 3 min produced grain. The alternate component was similar, but every 30 responses was also punished by a mild shock. Punished responding occurred at approximately 25% of the rate of unpunished responding. Cocaine (0.1-10.0 mg/kg IM) did not affect or decrease punished responding; unpunished responding was not systemically affected. Next, a foot treadle was installed and treadle presses postponed shocks for 25 s; shocks occurred every 5 s in the absence of pressing. The treadle was removed when shocks were reliably postponed. Next, the multiple schedule of key pecking was reinstated. At least one dose of cocaine now increased punished pecking; unpunished responding was not systematically altered. These results complement related findings with monkeys and show that pigeons are suitable subjects for studying the reversal of the effects of cocaine on punished responding by a history of postponing shock.
在通过电击延迟维持踏板按压的经历之前和之后，研究了可卡因对鸽子受惩罚和未受惩罚的啄键反应的影响。在一个程序组件中，3分钟后的第一次啄击会产生谷物。另一个组件类似，但每30次反应也会受到一次轻微电击的惩罚。受惩罚的反应发生率约为未受惩罚反应发生率的25%。可卡因（0.1 - 10.0毫克/千克，肌肉注射）对受惩罚的反应没有影响或使其减少；未受惩罚的反应未受到全身性影响。接下来，安装了一个脚踏板，踏板按压可使电击延迟25秒；在没有按压的情况下，每隔5秒就会出现一次电击。当电击被可靠延迟后，移除了踏板。接下来，恢复了啄键的多重程序。现在至少有一剂可卡因增加了受惩罚的啄击；未受惩罚的反应没有系统性改变。这些结果补充了与猴子相关的研究发现，并表明鸽子是研究可卡因对受惩罚反应的影响通过电击延迟经历而逆转的合适实验对象。
