Surgery plus anesthesia induces loss of attention in mice

Abstract

There is a need to develop animal models to study postoperative delirium. Inattention is one of the symptoms of delirium. Increases in the levels of α-synuclein and S100β have been reported to be associated with delirium. Therefore, we set out to determine the effects of surgery plus general anesthesia on the behavioral changes (including loss of attention) in mice and on the levels of α-synuclein and S100β in the brain tissues of these mice. C57BL/6J mice (2- to 8-months-old) had a simple laparotomy plus isoflurane anesthesia. The behavioral changes, including attention level and the speed of movements, were determined 12, 24, and 48 h after the surgery plus anesthesia in the mice. The levels of α-synuclein and S100β in the cortex of these mice following the surgery plus anesthesia were determined by Western blot analysis. We found that there was a loss of attention at 24, but not 12 or 48 h following the surgery plus anesthesia (49% ± 5 vs. 33% ± 2.9, P = 0.011, N = 12) in the mice without significantly affecting the speed of their movements. There were increases in the levels of total α-synuclein (139% ± 33.5 vs. 100% ± 13.7, P = 0.037, N = 6) and S100β (142% ± 7.7 vs. 100% ± 6, P = 0.002, N = 6) in the cortex of the mice 12 h following the surgery plus anesthesia. These findings suggested that the surgery plus isoflurane anesthesia might induce behavioral and biochemical/cellular changes associated with delirium. We could use the surgery plus anesthesia in mice to develop an animal model to study postoperative delirium.

Anesthesia and Surgery Impair Blood–Brain Barrier and Cognitive Function in Mice

“…Anesthesia and surgery (anesthesia/surgery) in rodents have been shown to induce cognitive impairment [( 1 – 10 , 33 ), reviewed in Ref. ( 11 )].…”

“…The 18-month-old mice are only available through National Institute of Aging, thus cannot be purchased from same company that provides the 9-month-old mice. Mice in the anesthesia/surgery group had a simple laparotomy under isoflurane anesthesia using the methods described in our previous studies ( 10 , 33 ). Specifically, we anesthetized each of the mice using 1.4% isoflurane in 100% oxygen in a transparent acrylic chamber.…”

“…The procedure for each mouse usually lasted about 10 min and we put the mouse back into the anesthesia chamber for up to 2 h to receive the rest of the anesthesia consisting of 1.4% isoflurane in 100% oxygen. We used this method because surgery could potentiate the anesthesia neurotoxicity and such combination of anesthesia and surgery had been shown to induce cognitive impairment ( 10 , 33 ). We maintained the rectal temperature of the mice at 37 ± 0.5°C during the anesthesia/surgery by using DC Temperature Control System (FHC, Bowdoinham, ME, USA).…”

SIRT3 activator honokiol ameliorates surgery/anesthesia‐induced cognitive decline in mice through anti‐oxidative stress and anti‐inflammatory in hippocampus

“…Actually, surgery/anesthesia exposure could alter the normal dynamics of both neuroinflammation and oxidative stress simultaneously, leading to an unhealthy state for the brain and cognitive dysfunction. Ren et.al found that surgery plus isoflurane could induce postoperative delirium and associated biochemical/cellular changes in mice . Surgery/anesthesia exposure model is closer to clinic practice.…”

“…Ren et.al found that surgery plus isoflurane could induce postoperative delirium and associated biochemical/cellular changes in mice. 10 Surgery/anesthesia exposure model is closer to clinic practice. However, the underlying mechanisms of neuroinflammation and oxidative stress on postoperative cognitive impairment remain still unclear.…”