THE EFFECTS OF DOPAMINE D_2 RECEPTOR AGONISTS AND ANTAGONISTS ON HIPPOCAMPAL CA1 REGION NEURONAL APOPTOSIS

Objective:To study the effects of dopamine D 2 receptor agonists and antagonists on hippocampal CA1 region neuronal apoptosis following forebrain ischemia in gerbils.Methods:Forebrain ischemia was induced by occlusion of bilateral common carotid arteries for 5 min.24 gerbils were randomly divided into sham group (Sham),ischemia-reperfusion group(I-R),D 2 receptor agonist group(I-PER) and D 2 receptor antagonist group(I-SPI).Open field test was used 7 d after ischemia.The number of surviving and apoptosis neurons in hippocampal CA1 region was counted.Results:Five minutes forebrain ischemia resulted in extensive damage in the hippocampus CA1 region for 7d after reperfusion.The behavioral mark in the I-R group were higher than that of Sham group and I-PER group (P0.01).The number of surviving neurons in I-R group was much less than that of Sham group (P0.01).The number of surviving neurons in I-PER group was much more than that of I-R group (P0.01).The number of apoptosis neurons in the three latter groups was more than that of Sham group (P0.05 or P0.01).The number of apoptosis neurons in I-PER group was less than that of I-R group (P0.05).Conclusions:Dopamine D 2 receptor agonisit significantly reduced the apoptosis neurons in hippocampal CA1 region and the behavior deficits in gerbils after transient ischemia.