Researchers investigated how methylene blue and photobiomodulation (light therapy) each improved cognitive function in an animal model of hepatic encephalopathy by examining their effects on cytochrome c-oxidase, a key enzyme in cellular energy production. Both treatments restored cognitive performance in affected animals, but through distinct mechanisms—methylene blue directly enhanced cytochrome c-oxidase activity while photobiomodulation worked through different pathways affecting the same enzyme. This animal model study provides mechanistic insight into how these interventions may address the mitochondrial dysfunction underlying cognitive impairment in hepatic encephalopathy.