Abdominal surgery plus sevoflurane exposure induces abnormal emotional changes and cognitive dysfunction in aged rats

Area of Science:

• Neuroscience
• Gerontology
• Surgical Research

Background:

• Cognitive impairment, including perioperative psychological distress and dysfunction, is a known post-surgical complication.
• The interplay between the immune system and the brain following surgery is complex and not fully understood.
• Perioperative neurocognitive disorders (PND) are a significant concern, particularly in elderly populations.

Purpose of the Study:

• To investigate the mechanisms underlying perioperative neurocognitive disorders (PND) in elderly rats.
• To utilize an experimental abdominal surgery model to assess cognitive and emotional changes post-surgery.
• To explore the neurobiological correlates of PND in aged rodents.

Main Methods:

• Elderly Sprague-Dawley rats underwent an abdominal surgery model (AEL) under anesthesia.
• Diffusion kurtosis imaging (DKI) measured fractional anisotropy (FA) at 15 and 30 days post-surgery.
• Behavioral tests (OFT, MWM, NOR, FST, EPM), pathological analysis, and Western blot were conducted.

Main Results:

• AEL exposure led to impaired performance in MWM, NOR, EPM, and FST, with altered OFT behavior.
• Decreased FA was observed in the medial prefrontal cortex (mPFC), nucleus accumbens (NAc), and hippocampus.
• Reduced neuronal markers (MAP2, GAD65, VGlut2, CHAT) and phosphorylated P38MAPK, alongside increased glial activation, were noted.

Conclusions:

• Aged rats undergoing abdominal surgery exhibited emotional and cognitive dysfunction.
• These deficits may be attributed to neuronal degeneration and altered signaling pathways, including reduced phosphorylated P38MAPK.
• The study provides insights into the neurobiological underpinnings of PND in the elderly.