Dickinson-Anson H, Mesches M H, Coleman K, McGaugh J L
Department of Psychobiology, University of California, Irvine 92717-3800.
Behav Neural Biol. 1993 Jul;60(1):1-4. doi: 10.1016/0163-1047(93)90638-x.
This experiment investigated the effect of intra-amygdala administration of the GABAergic antagonist bicuculline methiodide on benzodiazepine-induced amnesia. Male Sprague-Dawley rats were implanted bilaterally with cannulae aimed at the amygdala and allowed to recover for 1 week. Ten minutes before training in a continuous multiple trial inhibitory avoidance task a buffer solution or bicuculline methiodide (56 pmol/0.5 microliters) was injected bilaterally into the amygdala and this injection was immediately followed by a systemic injection of saline or midazolam (1.0 mg/kg). In comparison with saline controls, midazolam-treated animals required more trials to reach the acquisition criterion of remaining in the starting chamber for 100 s. The midazolam effect on acquisition was not attenuated by intra-amygdala infusion of bicuculline methiodide, suggesting that the midazolam-induced changes in acquisition behavior do not involve the amygdaloid GABAergic system. On a 48-h retention test the performance of the midazolam-treated animals was significantly poorer than that of the controls. However, the retention performance of animals given intra-amygdala injections of bicuculline methiodide prior to the systemic injection of midazolam was comparable to that of the saline controls. These results suggest that the amygdaloid GABAergic system mediates the impairing effects of midazolam on retention of inhibitory avoidance training.
本实验研究了向杏仁核内注射GABA能拮抗剂甲磺酸荷包牡丹碱对苯二氮䓬诱导失忆的影响。雄性Sprague-Dawley大鼠双侧植入针对杏仁核的套管，并使其恢复1周。在连续多次试验性抑制性回避任务训练前10分钟，将缓冲溶液或甲磺酸荷包牡丹碱（56皮摩尔/0.5微升）双侧注入杏仁核，随后立即全身注射生理盐水或咪达唑仑（1.0毫克/千克）。与生理盐水对照组相比，接受咪达唑仑治疗的动物需要更多次试验才能达到在起始室停留100秒的习得标准。向杏仁核内注入甲磺酸荷包牡丹碱并未减弱咪达唑仑对习得的影响，这表明咪达唑仑诱导的习得行为变化不涉及杏仁核GABA能系统。在48小时的记忆测试中，接受咪达唑仑治疗的动物的表现明显比对照组差。然而，在全身注射咪达唑仑之前接受杏仁核内注射甲磺酸荷包牡丹碱的动物的记忆表现与生理盐水对照组相当。这些结果表明，杏仁核GABA能系统介导了咪达唑仑对抑制性回避训练记忆的损害作用。
