Ultrastructural changes in the visual cortex of rats and the energy state of its mitochondria were studied during the week after a single intraperitoneal injection of methanol at a dose of 0.75 g/kg of their body weight was found that reactive changes in the structures of the visual cortex, located around the capil- laries, began in the first hours after methanol injection, with insignificant changes in mitochondrial biochemical markers. From the 1st day of observation, changes occurred in nerve and glial cells, which were manifested by the phenomena of hydropic dystrophy, which led to a disorder of their function- ing, to a violation of the conduction of nerve impulses and to a deficiency of nutrients in nerve cells due to mitochondrial dysfunction and the direct effect of methanol and its decom- position products on these components of the visual cortex. By the 7th day of the study, areas with pathological changes in the visual cortex were expanded, edematous and destructive changes increased in them, and the energy state decreased. At the same time, the number of polysomes increased in some nerve cells, which is of a compensatory and restorative nature.