Hyperpolarized 13C MRS can detect alterations in the astrocyte-neuron lactate shuttle (ANLS) in the healthy mouse brain

Motivation: To understand how hyperpolarized (HP) 13C MRS can provide information on the astrocyte-neuron lactate shuttle in the healthy brain. Goal(s): In this study, we assessed changes in whole brain energy metabolism after pharmacological blockage of astrocytic monocarboxylate transporters (MCTs), measured with HP [1-13C]pyruvate MRS. Approach: Paired HP 13C MRS experiments were performed before and after pharmacological MCT1/4 blocking in 4-month-old C57BL/6J mice, using different combination of metabolite-specific multi-band, spectral spatial (SPSP) sequence. Results: After astrocytic MCT blockage, the conversion of pyruvate to lactate and bicarbonate was decreased, in line with reduced astrocytic lactate production and neuronal aerobic respiration. Impact: This study indicates that HP 13C MRS can be used to investigate alterations in the astrocyte-neuron lactate shuttle in the brain, showing the potential in applying this method to investigate metabolic changes in neurological disorders.