Influence of hepatic ischemia-reperfusion on postoperative spatial cognitive function in mice

The aim of this study was to investigate the effects of partial hepatic ischemia/reperfusion (I/R) on postoperative cognitive function in mice. One hundred Kunming mice were randomized into control group (N = 20), sham group (N = 20) and I/R group (N = 60), which was equally divided into 3 subgroups according to the ischemia time (20, 30 and 40 min). Half of the mice in each group underwent a passive avoidance test on the 4th day, and the other underwent the test on the 18th day, which lasted for 6 days before euthanasia for analysis of brain pathology and immunohistochemistry for ChAT. The passive avoidance test showed that there was no significance in the incubation period and number of errors between the control and sham group, but there was a longer incubation period and more errors in the I/R group than control group; at G2, there was no significance between all groups. Hematoxylin-eosin staining of the hippocampus showed that at G1, there was no obvious change in hippocampal neurons in structure and arrangement except for IR/40 min; at G2, there was no significance between all groups. Immunohistochemistry of hippocampus for ChAT showed the following: at G1, there was no significance in average optical density of CA3 area between control and sham group, but optical density was significantly lower in I/R groups with I/R 40 min showing the lowest; at G2, there was no significance between all groups. Pentobarbital has no effect on cognitive function, but hepatic partial ischemia and reperfusion injury does and could become worse over time.