The effective prevention of
postoperative cognitive dysfunction (POCD) needs to be explored, and the effect of preoperative
pain on POCD remains unclear. We established a
chronic pain model induced by chronic constriction injury (CCI) and models of
acute pain and anxiety without
pain in mice that were subsequently subjected to partial
hepatectomy surgery. Morris water maze (MWM) tests were performed to evaluate the learning and memory abilities of the mice. ELISA was used to measure IL-1β,
IL-6, and TNF-α in serum, and HPLC-MS was used to detect
neurotransmitters in the prefrontal cortices and hippocampi of the mice. The results indicated that
chronic pain induced by CCI might have significantly impaired the learning and memory abilities of mice, while
acute pain and anxiety without
pain only affected the memory abilities of mice. Perioperative
acute pain increased the level of IL-1β in serum, and CCI might have increased the level of
IL-6. CCI and
acute pain increased
dopamine (DA) levels in the cortex, similar to anxiety. Like anxiety, CCI increased
5-hydroxytryptamine (5-HT) levels in the prefrontal cortex and hippocampus.
Acute pain led to a decrease in the
acetylcholine (ACH) level in the hippocampus. Our results suggest that
acute pain and CCI-induced
chronic pain might aggravate
postoperative cognitive dysfunction via
neurotransmitters and by changing the levels of inflammatory factors such as IL-1β and
IL-6.