Effect of rapamycin on infantile amnesia
10.3760/cma.j.issn.1671-8925.2016.04.006
- VernacularTitle:雷帕霉素对婴儿期遗忘作用的研究
- Author:
Xiufen ZHANG
1
;
Haiwen GUO
;
Jiang DU
;
Xizhong ZHOU
;
Suzhen FANG
;
Hong LI
Author Information
1. 南方医科大学珠江医院儿科中心
- Keywords:
Infantile amnesia;
Rapamycin;
Neurogenesis
- From:
Chinese Journal of Neuromedicine
2016;15(4):355-360
- CountryChina
- Language:Chinese
-
Abstract:
Objective To verify the infantile amnesia phenomenon and discuss the effect of rapamycin injection on infantile amnesia and hippocampal neurogenesis.Methods (1) In experiment one,17-day-old (P17) and 60-day-old (P60) male Sprague-Dawley rats (n=84) were trained in a passive-avoidance task (they were randomly sub-divided into the shocked group and non-shocked group);all rats were tested immediately,2 and 7 days after training for memory retention.(2) In experiment two,P17 rats (n=84) were randomly divided into three groups:vehicle group,20 mg/kg rapamycin group and 40 mg/kg rapamycin group (they were sub-divided into the shocked group and non-shocked group);P17 rats were immediately injected with either vehicle or rapamycin after passive-avoidance training,and memory retention was evaluated 2 and 7 days after training.(3) In experiment three,P1 7 rats (n=48) were randomly divided into four groups:normal group,vehicle group,20 mg/kg rapamycin group and 40 mg/kg rapamycin group;immunofluorescence staining of BrdU/DCX was detected to observe the hippocampal neurogenesis at post-natal day 19 (P19) and post-natal day 24 (P24) after vehicle or rapamycin injection at P17 rats.Results In experiment one,P17 and P60 shocked rats exhibited comparable levels of crossing latencies when being tested immediately (P＞0.05),when being tested after 2 days and 7 days,P17 rats forgot more rapidly than P60 rats (P＜0.05);there were no age-related differences in crossing latencies between the non-shocked groups (P＞0.05).In experiment two,three shocked groups exhibited comparable levels of crossing latencies when being tested 2 days after training (P＞0.05),however,administration of rapamycin could enhance the memory retention 7 days after training;significant differences were noted between the vehicle group and each of the rapamycin treated groups (P＜0.05);there were no dose-related differences in crossing latencies among the non-shocked groups (P＞0.05).In experiment three,less BrdU-positive and BrdU/DCX-positive cells were found in the DG of the hippocampus at 20 mg/kg and 40 mg/kg rapamycin groups as compared with those in the vehicle group at P19 and P24 rats (P＜0.05).Conclusion The infantile amnesia phenomenon is verified,and rapamycin may enhance the memory retention in infant rats by reducing the hippocampal neurogenesis.
