Perioperative behavioural changes and hippocampal noradrenaline alterations in type 2 diabetes model mice
Postoperative mental illness is one of the problems in patients with diabetes mellitus. However, the pathophysiology is unclear. Recently, a deficiency of neurotransmitters was reported to be associated with mental disorders. Therefore, we investigated the effects of surgical stress on behaviors and the hippocampal noradrenaline (NA) level in type 2 diabetes mellitus model (T2DM) mice. Eighty-four 6-week-old male C57BL/6J mice were divided into four groups (control, surgery control, T2DM, and surgery T2DM groups). T2DM mice were established by feeding a high fat diet (HFD). At 14 weeks of age, fifteen mice in every group underwent a series of behavioral tests including an open field (OF) test, a novel objective recognition (NOR) test and a light-dark box (LD) test. In the surgery groups, open abdominal surgery was performed 24 hours before the tests. Hippocampal NA was examined in six mice in each group by high-performance liquid chromatography.