A Novel Individual-based Determination of Postoperative Cognitive Dysfunction in Mice

Area of Science:

• Neuroscience
• Anesthesiology
• Gerontology

Background:

• Postoperative cognitive dysfunction (POCD) is a significant clinical concern, particularly in aging populations.
• Current animal studies assess POCD on a group basis, hindering biomarker and intervention evaluation.
• Individualized assessment of POCD in animals is needed for accurate preclinical research.

Purpose of the Study:

• To determine if an individual-based assessment system for POCD, similar to human clinical evaluations, can be applied to mice.
• To investigate the impact of surgery on cognitive function in young adult and old mice.

Main Methods:

• Seven-week-old and 18-month-old male mice underwent carotid arterial exposure under anesthesia.
• Cognitive function was assessed using the Barnes maze and fear conditioning tests.
• An individual-based assessment method, comparing pre- and post-surgery performance, was employed.

Main Results:

• Surgery significantly impaired performance in the Barnes maze and fear conditioning tests in both young and old mice.
• The incidence of cognitive dysfunction was significantly higher in surgical groups compared to controls for both age groups (P = 0.045 for young, P < 0.001 for old).
• Individual animal assessment successfully identified mice exhibiting cognitive dysfunction post-surgery.

Conclusions:

• Surgery induces postoperative cognitive dysfunction (POCD) in mice.
• An individual animal-based assessment is effective for identifying POCD in preclinical studies.
• This approach facilitates better evaluation of POCD biomarkers and therapeutic interventions.