Department of Biology, College of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
J Zhejiang Univ Sci B. 2011 Nov;12(11):900-8. doi: 10.1631/jzus.B1000340.
In this study we investigated whether GABA(A) receptors of the basolateral amygdala (BLA) interact with the effect of dexamethasone on the retrieval stage of memory. Adult male Wistar rats were bilaterally cannulated in the BLA by stereotaxic surgery. The animals were trained in step-through apparatus by induction of electric shock (1.5 mA, 3 s) and were tested for memory retrieval after 1 d. The time of latency for entering the dark compartment of the instrument and the time spent by rats in this chamber were recorded for evaluation of the animals' retrieval in passive avoidance memory. Administration of dexamethasone (0.3 and 0.9 mg/kg, subcutaneously (s.c.)), immediately after training, enhanced memory retrieval. This effect was reduced by intra-BLA microinjection of muscimol (0.125, 0.250 and 0.500 µg/rat), when administered before 0.9 mg/kg of dexamethasone. Microinjection of bicuculline (0.75 µg/rat, intra-BLA) with an ineffective dose of dexamethasone (0.1 mg/kg, s.c.) increased memory retrieval. However, the same doses of muscimol and bicuculline without dexamethasone did not affect memory processes. Our data support reports that dexamethasone enhances memory retrieval. It seems that GABA(A) receptors of the BLA mediate the effect of dexamethasone on memory retrieval in rats.
在这项研究中,我们调查了基底外侧杏仁核(BLA)中的 GABA(A) 受体是否与地塞米松对记忆检索阶段的影响相互作用。成年雄性 Wistar 大鼠通过立体定向手术双侧植入 BLA 导管。动物通过诱导电击(1.5 mA,3 s)在步入式仪器中进行训练,并在 1 天后进行记忆检索测试。记录动物进入仪器黑暗室的潜伏期时间和在该室中花费的时间,以评估动物在被动回避记忆中的检索。地塞米松(0.3 和 0.9 mg/kg,皮下(s.c.))在训练后立即给药可增强记忆检索。当在 0.9 mg/kg 地塞米松之前给予时,BLA 内微注射 muscimol(0.125、0.250 和 0.500 µg/大鼠)会降低这种作用。BLA 内微注射 bicuculline(0.75 µg/大鼠)与无效剂量的地塞米松(0.1 mg/kg,s.c.)可增加记忆检索。然而,没有地塞米松的相同剂量的 muscimol 和 bicuculline 不会影响记忆过程。我们的数据支持地塞米松增强记忆检索的报告。似乎 BLA 中的 GABA(A) 受体介导了地塞米松对大鼠记忆检索的影响。