A mouse imaging study shows why tracer delivery and receptor-related uptake cannot always be read separately.
Mice received lipopolysaccharide to model systemic inflammation. Four hours later, researchers assessed perfusion, glucose uptake, and benzodiazepine-receptor-related iomazenil uptake, with additional inflammatory measurements. Perfusion decreased while glucose and microglial-tracer uptake increased. After compensation for perfusion, iomazenil uptake was increased in the hippocampus and cerebellum.
The analysis therefore depended on accounting for blood delivery, not simply reading an unqualified uptake value as neuronal loss.
This acute mouse model is not the complete clinical syndrome of human sepsis-associated encephalopathy. Changes in uptake do not by themselves establish a benzodiazepine treatment effect, intoxication, or permanent injury. Different tracers measure different physiological aspects.
For interpretation, retain species, inflammatory timing, tracer identity, and the correction applied. The paper contributes a methodological finding about imaging under inflammation. It cannot establish the cause of one person’s confusion or provide a conversion between a tracer signal and a sedative drug concentration.
Original analysis of the supplied journal article, identified as PMC6244542.