Observation the function of Citalopram on hippocampus neurogenesis and serotonin 1A receptor expression in transient cerebral ischemic rat

Objective To investigate the neurogenetic function of Citalopram and serotonin 1A receptor expression in hippocampus on transient cerebral ischemic rat and the relationship between them.Methods 78 Wistar rats were randomly divided into four groups:normal control group(NC),sham operation control group(SC),transient cerebral ischemic group(4VO) and citalopram treated transient cerebral ischemic group(4VO+C).All ischemic rats were treated with improved Pulsinelli′s 4-vessle occlusion.Neurogesis in hippocampus was observed by BrdU(Bromodeoxyuridine) immunofluorescence and confocal laser scanning microscope technique.The expression of serotonin 1A receptor in hippocampus was measured by means of real-time PCR.Results(1)Most of the BrdU-positive cells were detected in dentate gyrus and were generally in pairs or clusters distributed at the border of the granule cell layer and hilus.One day after transient cerebral ischemia,numbers of BrdU-positive cells were obviously decreased in both 4VO and 4VO+C groups(P=0.002).After then,numbers of BrdU-positive cells were gradually upgraded and reached its peak at 14 days after operation and it was twice as much in 4VO+C group than that in 4VO group.Besides,neurogenesis was vividly continued 21 days after operation in 4VO+C group(P=0.00017 compared with 4VO group).(2)One day after transient cerebral ischemia,the relative expression level of serotonin 1A receptor mRNA dropped down obviously in both 4VO and 4VO+C groups(P0.01).It began to raise up from 3 to 14 days in both groups,and it reached its peak 7 days after ischemia and 7 days earlier than that in 4VO group.After 14 days of ischemic injury,serotonin 1A receptor mRNA expression decreased in either group but still obviously higher than that in NC and SC groups 21 days after operation.Compared with 4VO group,serotonin 1A receptor mRNA expression in every subgroup of 4VO+C group was significantly higher except 1-day subgroup.(3)The tendency of neugenesis in adult dentate gyrus was significantly correlated with the expression of serotonin 1A receptor in hippocampus(r=0.8498).Conclusion In rat Pulsinelli′s 4-vessle occlusion model,transient cerebral ischemia could stimulates neurogenesis in adult dentate gyrus and it could be further improved by treating with citalopram.In addition,this function of citalopram may be correlated with the expression of serotonin 1A receptor in hippocampus.