Aspartic acid in the hippocampus: a biomarker for postoperative cognitive dysfunction

Area of Science:

• Neuroscience
• Biochemistry
• Anesthesiology

Background:

• Anesthesia, particularly isoflurane, is widely used in aged patients.
• Cognitive dysfunction is a potential complication following anesthesia in the elderly.
• The underlying mechanisms of anesthesia-induced cognitive dysfunction remain incompletely understood.

Purpose of the Study:

• To investigate the effects of isoflurane anesthesia on cognitive function in aged rats.
• To identify specific hippocampal metabolites altered by isoflurane anesthesia.
• To explore the potential role of these metabolites as biomarkers for cognitive dysfunction.

Main Methods:

• Establishment of an aged rat model of cognitive dysfunction induced by isoflurane anesthesia.
• Assessment of cognitive function using the Y-maze test.
• Analysis of hippocampal metabolite profiles using gas chromatography-mass spectrometry (GC-MS).
• In vitro culture of hippocampal neurons treated with aspartic acid.

Main Results:

• Isoflurane anesthesia significantly impaired cognitive function in aged rats.
• Increased levels of N,N-diethylacetamide, n-ethylacetamide, aspartic acid, malic acid, and arabinonic acid were observed in the hippocampus.
• Positive correlations were found between aspartic acid, N,N-diethylacetamide, n-ethylacetamide, malic acid concentrations and the degree of cognitive impairment.
• In vitro treatment with aspartic acid suggested its potential as a predictive biomarker.

Conclusions:

• Hippocampal metabolite alterations are implicated in the development of cognitive dysfunction following isoflurane anesthesia.
• Aspartic acid concentration in the hippocampus may serve as a valuable biomarker for predicting anesthesia-related cognitive dysfunction and its progression.