The immune system and memory consolidation: a role for the cytokine IL-1 beta

Interleukin-1 beta(IL-1 beta), known to play a role in orchestrating the ph ysiological and behavioral adjustments that occur during sickness, has also been shown to significantly influence memory consolidation. To support thi s assertion we present neurobiological evidence that the substrates for IL- 1 beta to influence memory processing and neural plasticity exist. We then present behavioral evidence that central IL-1 beta administration and agent s that induce central IL-1 beta activity impair the consolidation of memori es that depend on the hippocampal formation but have no effect on the conso lidation of hippocampal-independent memories. Further, we demonstrate that the impairments in hippocampal-dependent memory consolidation produced by a gents that induce IL-1 beta activity are blocked by antagonizing the action s of IL-1 beta. Finally, we discuss these data in terms of their implicatio ns for a physiological role of IL-1 beta in memory consolidation processes and a potential role of IL-1 beta in producing memory impairments associate d with stress, aging, Alzheimer's disease, and AIDS related dementia comple x. (C) 2001 Elsevier Science Ltd. All rights reserved.