Andrade Chittaranjan, Thyagarajan S, Vinod P S, Srikanth S N, Rao N S K, Chandra J Suresh
Department of Psychopharmacology, National Institute of Mental Health and Neurosciences, Bangalore, India.
J ECT. 2002 Dec;18(4):197-202. doi: 10.1097/00124509-200212000-00006.
Animal models are frequently used to generate and test hypotheses about amnesia resulting from electroconvulsive therapy (ECT). Although many predictors of ECT-induced amnesia are known, their relative effects have been inadequately researched in the context of the animal models.
We sought to determine the relative retrograde amnestic effects of electroconvulsive shock (ECS) stimulus intensity (dose) and number on strong memories in rats. We also sought to identify dose-dependent ceiling amnestic effects, if any.
Adult rats (n = 144) were overtrained in a passive avoidance task using a step down apparatus. The rats were then randomized in a factorial design to receive one, two, or three once-daily bilateral ECS at 0-mC (sham ECS), 30-mC, 60-mC, 120-mC, or 180-mC doses. Recall of the pre-ECS training was assessed 1 day after the last ECS.
Retrograde amnesia was observed only in rats that received 3 ECS; dose-dependent amnestic effects did not emerge. Higher stimulus intensity was associated with a small (13%) but significant increase in motor seizure duration, but only at the first ECS; stimulus intensity did not influence the attenuation of seizure duration across repeated occasions of ECS.
With bilateral ECS, the number of ECSs administered is a more important variable than the ECS dose in weakening a strong, recently acquired, noxious memory; this finding may have important clinical implications. Higher stimulus intensity marginally increases motor seizure duration at the first ECS but does not influence the decrease in seizure duration across repeated ECSs.
动物模型常用于生成和检验关于电休克治疗（ECT）所致失忆的假说。尽管已知许多ECT所致失忆的预测因素，但在动物模型背景下，它们的相对效应尚未得到充分研究。
我们试图确定电休克（ECS）刺激强度（剂量）和次数对大鼠强记忆的相对逆行性遗忘效应。我们还试图确定是否存在剂量依赖性极限遗忘效应。
成年大鼠（n = 144）使用阶梯式下降装置在被动回避任务中进行过度训练。然后将大鼠按析因设计随机分组，每天接受一次、两次或三次双侧ECS，剂量分别为0 mC（假ECS）、30 mC、60 mC、120 mC或180 mC。在最后一次ECS后1天评估对ECS前训练的记忆恢复情况。
仅在接受3次ECS的大鼠中观察到逆行性遗忘；未出现剂量依赖性遗忘效应。较高的刺激强度与运动性癫痫发作持续时间小幅（13%）但显著增加有关，但仅在首次ECS时出现；刺激强度不影响重复ECS时癫痫发作持续时间的衰减。
对于双侧ECS，在削弱强烈的、近期获得的有害记忆方面，给予ECS的次数比ECS剂量是更重要的变量；这一发现可能具有重要的临床意义。较高的刺激强度在首次ECS时略微增加运动性癫痫发作持续时间，但不影响重复ECS时癫痫发作持续时间的缩短。
