We studied hippocampal variability in relation to the multiyear population density cycle and the action of density-dependent autoregulatory mechanisms associated with behavior. A study of field collections of the morphological material of bank voles (Clethrionomysglareolus, Rodentia) revealed annual variability in the hippocampal size against changes in the population density. The absolute and relative mass of the hippocampus was significantly higher in young autumn voles in the year of population peak against the background of a pronounced stress reaction manifested in an increased mass of the adrenal glands. This peculiarity of brain morphology persisted throughout the life cycle of animals born in the year of a population peak. Possible factors and mechanisms of hippocampal variability in connection with the dynamics of population density are discussed.
展开▼
