Brain consciousness affects HP lactate labeling from HP pyruvate

Motivation: Brain metabolism and activity are closely related. General anesthesia, commonly used in preclinical studies, alters functional connectivity, hemodynamics and metabolism. In preclinical MR, metabolic studies frequently employ isoflurane, while a medetomidine-isoflurane combination is preferred for fMRI. Detection of HP substrate conversions is the sole MR technology capable to capture real-time metabolism. Goal(s): Towards rodent fMRSI studies, we aim to compare the cerebral metabolism of HP [1-13C] pyruvate between mice under isoflurane-only and combined medetomidine-isoflurane anesthesia. Approach: Dynamic MRSI at high spatiotemporal resolution characterized HP pyruvate metabolism. Results: Pyruvate-to-lactate turnover is lower and delayed under medetomidine-isoflurane compared to isoflurane-only anesthesia. Impact: Anesthesia can modulate brain consciousness. Significantly higher hyperpolarized pyruvate-to-lactate turnover is observed in mice under isoflurane-only compared to medetomidine-isoflurane anesthesia. Beyond this finding’s relevance for preclinical studies, this opens opportunities for probing brain biochemistry in patients under general anesthesia.