Methylene blue has been around for nearly a century and is mostly used to treat methemoglobinemia. New data, however, suggests that a single dose of methylene blue enhances the response of brain regions that control attention and short-term memory.

The study, “Multimodal Randmoized Functional MR Imaging of the Effects of Methylene Blue in the Human Brain,” published in Radiology, used multimodal functional MRI to investigate the neural correlates of methylene blue in humans.

The local ethical committee approved 26 healthy, English-speaking participants, between the ages of 18 and 65 for this study. fMRI was performed before and an hour after administration of low-dose methylene blue or a placebo.

Researchers found that participants who were given the drug had an increased response in the bilateral insular cortex. During short-term memory tasks, there was also an increase in the brain’s prefrontal cortex, the parietal lobe and the occipital cortex. Participants who were given methylene blue also had a 7 percent increase in correct responses during memory retrieval.  

“This work provides a neuroimaging foundation to pursue clinical trials of methylene blue in patients undergoing healthy aging and those with cognitive impairment, dementia, or other conditions who may benefit from drug-induced memory enhancement,” the authors wrote.