Dykstra L A
J Pharmacol Exp Ther. 1979 May;209(2):297-303.
The effects of morphine, diazepam and chlorpromazine were examined on the discrimination of electric shock in squirrel monkeys. Two discrete responses measured discrimination of the presence or absence of shock at two different intensities, either at 0.35 mA or at an intensity determined to be close to each monkey's threshold (0.05 or 0.15 mA). The percentage of responses which were correct in the presence and the absence of shock were determined separately. Time to respond to the presence or the absence of shock was also determined. Morphine decreased the percentage of correct responses at both the lower (0.05--0.15 mA) and the higher (0.35 mA) shock intensities, although effects at the higher intensity were very slight. Morphine had little effect on correct responses in the absence of shock. In contrast, diazepam decreased the percentage of correct responses in the absence of shock without affecting correct responses in the presence of shock, and chlorpromazine decreased the percentage of correct responses both in the presence and absence of shock. All three drugs increased time to respond both to the presence of shock and to the absence of shock with chlorpromazine producing the largest increase. Only morphine increased time to respond in the absence of shock more than in the presence of shock.
研究了吗啡、地西泮和氯丙嗪对松鼠猴电击辨别能力的影响。通过两种离散反应来测量对两种不同强度电击（0.35毫安或接近每只猴子阈值的强度，即0.05或0.15毫安）存在或不存在的辨别能力。分别测定了有电击和无电击时正确反应的百分比。还测定了对电击存在或不存在的反应时间。吗啡在较低（0.05 - 0.15毫安）和较高（0.35毫安）电击强度下均降低了正确反应的百分比，不过在较高强度下的影响非常轻微。吗啡对无电击时的正确反应影响很小。相比之下，地西泮降低了无电击时正确反应的百分比，而不影响有电击时的正确反应，氯丙嗪则降低了有电击和无电击时正确反应的百分比。这三种药物均增加了对电击存在和不存在的反应时间，其中氯丙嗪的增加幅度最大。只有吗啡在无电击时比有电击时增加的反应时间更多。
