Beneficial network effects of methylene blue in an amnestic model

► Methylene blue (MB) improves memory in a model of mild cognitive impairment (MCI). ► MB reduces the lesion volume induced by posterior cingulate hypometabolism. ► MB normalizes the effective connectivity of the posterior cingulate cortex. ► MB modifies network functional connectivity within the circuit of Papez. ► This is the first study of MB's beneficial effects in a model of amnestic MCI.