Boccia M.M., Kopf S.R., Baratti C.M.
Laboratorio de Neurofarmacología de Procesos de Memoria, Cátedra de Farmacología - Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956-5 degrees Piso, 1113 - Buenos Aires, Argentina.
Behav Pharmacol. 1996 May;7(3):254-260.
Male Swiss mice were tested 48h after training in a one-trial step-through inhibitory avoidance task. Immediately post-training i.p. injection of the GABA antagonist picrotoxin (0.3-3.0mg/kg), at nonconvulsive doses, induced a dose-dependent modification of retention performance. The lower doses of picrotoxin (0.1-1.0mg/kg) enhanced retention, whereas the highest dose (3.0mg/kg) impaired retention. Picrotoxin did not affect response latencies in mice not given the footshock on the training trial, indicating that the actions of picrotoxin on retention performance were not due to nonspecific proactive effects on response latencies. The enhancing effects of picrotoxin (1.0mg/kg) on retention were time-dependent, which suggests that picrotoxin enhanced storage of recently acquired information. The enhancement of retention induced by picrotoxin (1.0mg/kg) was prevented by the vasopressin receptor antagonist, AAVP (0.01µg/kg, s.c.) administered immediately after training, but prior to picrotoxin treatment. This dose of AAVP did not affect retention by itself, either under the standard experimental conditions, or in mice trained with a high footshock. Low subeffective doses of picrotoxin (0.1mg/kg, s.c.) administered immediately after training, and hypertonic saline (1ml of 0.5M NaCl, i.p.), given 10min after training, interacted to improve retention. Considered together, these findings suggest that the better retention performance induced by post-training administration of picrotoxin could result, at least in part, from an endogenous release of vasopressin.
在单次尝试穿梭抑制性回避任务训练后48小时对雄性瑞士小鼠进行测试。训练后立即腹腔注射非惊厥剂量的GABA拮抗剂印防己毒素（0.3 - 3.0mg/kg），可诱导记忆保持表现出现剂量依赖性改变。较低剂量的印防己毒素（0.1 - 1.0mg/kg）增强了记忆保持，而最高剂量（3.0mg/kg）则损害了记忆保持。印防己毒素对训练试验中未给予电击的小鼠的反应潜伏期没有影响，这表明印防己毒素对记忆保持表现的作用并非由于对反应潜伏期的非特异性前摄效应。印防己毒素（1.0mg/kg）对记忆保持的增强作用具有时间依赖性，这表明印防己毒素增强了最近获取信息的存储。训练后立即给予血管加压素受体拮抗剂AAVP（0.01μg/kg，皮下注射），但在印防己毒素治疗之前，可阻止印防己毒素（1.0mg/kg）诱导的记忆保持增强。该剂量的AAVP本身在标准实验条件下或在接受高强度电击训练的小鼠中均不影响记忆保持。训练后立即皮下注射低亚有效剂量的印防己毒素（0.1mg/kg）和训练10分钟后腹腔注射高渗盐水（1ml 0.5M NaCl）共同作用可改善记忆保持。综合考虑，这些发现表明训练后给予印防己毒素所诱导的更好的记忆保持表现可能至少部分源于血管加压素的内源性释放。
