Linear relation between cerebral phosphocreatine concentration and memory capacities during permanent brain vessel occlusions in rats

The present study investigates the interrelation between cerebral energy state and memory capacities in a rat model of stepwise cerebral vessel occlusions, After acute and subchronic permanent vessel occlusions, cortical energy metabolites (ATP, phosphocreatine, ADP, AMP) were detected by high-pressure liquid chromatography (HPLC) analysis, and the effects on learning, memory, and cognitive behavior were evaluated using a holeboard test. The results of the study demonstrated a drastic decrease in energy-rich phosphates by 33% for phosphocreatine and by 44% for ATP after acute vessel occlusions, In addition, rat working and reference memories were strikingly decreased to about 5% of controls, In contrast, two weeks after four-vessel occlusion, the energy state was almost completely restored to control levels. However, a significant decrease in memory capacities was observed in subchronic state. In summary, this study has demonstrated a close linear relationship (p < 0.001) between an impaired cerebral energy state and brain memory dysfunction after acute and permanent cerebral four-vessel occlusion, Thus, this animal model of stepwise reduction of the cerebral blood supply may reflect some clinically relevant processes occurring during cerebrovascular and neurodegenerative diseases.