Sci Tech Daily Japanese researchers uncover the molecular signature of Long COVID brain fog, a breakthrough that could bring real treatments closer than ever. Researchers in Japan have pinpointed a biological cause of Long COVID brain fog using advanced PET brain imaging. They discovered widespread increases in AMPA receptor density linked to cognitive impairment and inflammation. The findings confirm brain fog as a measurable, biological condition and reveal new targets for treatment. This could open the door to effective diagnostics and therapies.