Although increasing evidences suggest a relationship between
hypertension and brain function for years, it is still unclear whether
hypertension constitutes a risk factor for
cognitive decline and its underlying mechanism. In the present study, an experimental animal model of
hypertension simply by feeding rats with high
salt diet was employed. We found that long-term high
salt intake caused a marked increase of systolic blood pressure linked to a declined regional cerebral blood flow. Fear conditioning and morris water maze behavioral test revealed that high
salt diet induced hippocampal dependent spatial reference
memory deficits, while a decreased synaptogenesis without neuronal loss in hippocampus was observed in high
salt treated rats. Furthermore, we found that high
salt induced a decrease of intracellular
calcium, which inactivated CaMK II and resulted in dephosphorylation of CREB at Ser133. These findings suggest a novel etiopathogenic mechanism of cognitive deficit induced by
hypertension, which is initiated by high
salt diet.