AIMTo investigate the resting [Ca2]i level and expression of calmodulin (CaM), calmodulin-dependent protein kinase II (CaMPKII) mRNA in hippocampal neurons of the mice with vascular dementia (VD) and their roles in the pathogenesis of VD.

METHODSThe mice were subjected for ischemia/reperfusion repeatedly on bilateral common carotid arteries by knots to establish the VD models. Animals with the sham-operation were taken as control group. The changes of behavior were observed through the step-down avoidance test and water maze test on the day 29, 30 after the operations. The hippocampal neurons were obtained immediately after mice were sacrificed and the resting [Ca2+]i was measured using laser scanning confocal microscopy with Fluo-3/AM as fluorescence indicator. RT-PCR technique was used to measure the mRNA expression of CaM, CaMPKII in hippocampal neurons.

RESULTS(1) The abilities of learning and memorizing in model group were inferior to those of sham-operation group( P < 0.05). (2) The resting [Ca2]i level in model group was significantly higher than sham-operation group (P < 0.05), while the expression of CaMmRNA, CaMPKIImRNA in VD group was significantly reduced than sham-operation group (P < 0.01).

CONCLUSIONOur study indicates that excessive resting[Ca2+ ]i level and lower CaM, CaMPKII expression in hippocampal neurons might participate in the pathogenesis of VD.