Electron microscopy was used to explore ultrastructural changes in the lateral hypothalamic area (LHA) of rats 1, 3, 5 and 7 days after food deprivation. Special attention was paid to studies on changes in LHA dendrites which carry out receptive function. The dendrites were shown to be the most vulnerable and to be affected earlier than other components of neurons (somas, axons). The time course of pathomorphological changes in the dendrites, namely from initial to gross destructive ones, was specified. The characteristic changes in the dendrites included invagination into the dendritic cytoplasm of adjacent structures, mostly axons, with destructive changes in the area of invaginated parts. Invagination could be observed since the third day and was the most demonstrable on the 7th day of food deprivation. The possible mechanisms of such invaginations are discussed.