Involvement of basolateral amygdala GABAA receptors in the effect of dexamethasone on memory in rats  

作　　者：Lotfollah KHAJEHPOUR Acieh ALIZADEH-MAKVANDI Mahnaz KESMATI Hooman ESHAGH-HAROONI 

机构地区：[1]Department of Biology,College of Science,Shahid Chamran University of Ahvaz

出　　处：《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》2011年第11期900-908,共9页浙江大学学报（英文版）B辑（生物医学与生物技术）

基　　金：supported by the Shahid Chamran University of Ahvaz,Iran

摘　　要：In this study we investigated whether GABAA 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 GABAA receptors of the BLA mediate the effect of dexamethasone on memory retrieval in rats.In this study we investigated whether GABAA 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 GABAA receptors of the BLA mediate the effect of dexamethasone on memory retrieval in rats.

关 键 词：Basolateral amygdala DEXAMETHASONE MUSCIMOL BICUCULLINE Passive avoidance task 

分 类 号：R285[医药卫生—中药学]