Guillermain Y, Micallef J, Possamaï C, Blin O, Hasbroucq T
Centre de Recherches en Neurosciences Cognitives, Centre National de la Recherche Scientifique, 13402 Marseille Cedex 20, France.
Neurosci Lett. 2001 Apr 27;303(1):29-32. doi: 10.1016/s0304-3940(01)01695-0.
Ketamine is an N-methyl-D-aspartate antagonist that induces cognitive dysfunctions. The purpose of the present study was to investigate the effects of a subanesthetic dose of ketamine on human information processing, using the additive factor method. During perfusion of a subanesthetic dose of ketamine (0.5 mg/kg over 60 min) or a placebo (randomized double-blind, cross-over design), eight adults (aged 22-33, mean=27) performed a two-choice visual reaction time (RT) task. Signal intensity, stimulus-response mapping, and foreperiod duration were manipulated. The effects of these three variables were found to be additive on RT, indicating that three independent stages - namely, stimulus preprocessing, response selection and motor selection- were manipulated. Ketamine altered RT performance in a specific way: it interacted with foreperiod duration but its effect was additive with those of signal intensity and stimulus-response mapping. These results show that ketamine specifically affects the stage of motor adjustment, which suggests that the glutamatergic system plays an important role in motor processes.
氯胺酮是一种可诱发认知功能障碍的N-甲基-D-天冬氨酸拮抗剂。本研究的目的是使用相加因素法研究亚麻醉剂量的氯胺酮对人类信息处理的影响。在输注亚麻醉剂量的氯胺酮（60分钟内输注0.5毫克/千克）或安慰剂（随机双盲、交叉设计）期间，八名成年人（年龄22-33岁，平均年龄=27岁）进行了二选一视觉反应时（RT）任务。对信号强度、刺激-反应映射和预备期持续时间进行了操控。发现这三个变量对反应时的影响是相加的，表明操控了三个独立阶段，即刺激预处理、反应选择和运动选择。氯胺酮以一种特定的方式改变了反应时表现：它与预备期持续时间相互作用，但其效应与信号强度和刺激-反应映射的效应是相加的。这些结果表明，氯胺酮特异性地影响运动调整阶段，这表明谷氨酸能系统在运动过程中起重要作用。
