Dahl RH, et al. – Clinicians examined data from a previous study on the transcerebral net exchange of large neutral amino acids (LNAAs) using a novel mathematical model of blood–brain barrier (BBB) transport. The results of this study displayed that lipopolysaccharide (LPS) infusion leads to an increased cerebral uptake of phenylalanine, which is then metabolized to tyrosine. Moreover, this may reflect a neuroprotective mechanism that ‘detoxifies’ excess intracerebral phenylalanine in the clinical setting of sepsis.