Anesthesia, perimortem conditions, and brain harvest method govern the measured metabolome: Analysis of substandard samples generates flawed metabolite levels

Metabolism and energetics are closely integrated with brain function, and understanding how metabolic dysfunction contributes to neurological disease may help improve therapeutic approaches. Characterization of in situ metabolite levels, spatial distributions, and metabolomes requires special attention to anesthesia use, perimortem conditions, and tissue harvest. Anesthesia, CO2 asphyxiation, vascular perfusion, and decapitation alter metabolism, thereby substantially changing the metabolome, lipidome, and neurotransmitter profile. Analysis of flawed samples produces artifactual data, raising concerns about conclusions regarding the cellular basis of metabolism, metabolite shuttling, pathway activities, labeled metabolite profiling and imaging, and relationships between metabolism, function, and neurological disorders. Appropriate procedures for in vivo metabolic assays and tissue harvest are widely-unrecognized but essential components of metabolic and metabolomic studies.