ReviewNeuroinflammatory changes negatively impact on LTP: A focus on IL-1β

•Inflammatory cytokines negatively impact on LTP.•The effect of IL-1β on LTP is dose-dependent.•A role for the inflammasome in synaptic plasticity has been identified.•If microglia adopt an M1-like inflammatory phenotype LTP is decreased.•When microglia adopt an M2-like anti-inflammatory phenotype, LTP is preserved.This article is part of a Special Issue entitled SI: Brain and Memory.This article is part of a Special Issue entitled SI: Brain and Memory.

In recent years it has become clear that neuroinflammatory changes develop in the brain with age and that similar, though more profound changes, occur in neurodegenerative conditions and in animal models of neurodegeneration. These changes are linked with deterioration in plasticity and the evidence suggests that a key causative factor is microglial activation and the associated increase in production and release of inflammatory cytokines. Several groups have reported that interleukin (IL)-1β negatively impacts on hippocampal-dependent learning and has an inhibitory effect on LTP although this is concentration-dependent. Similarly other inflammatory cytokines, which are also produced by microglia similarly decrease LTP. The evidence supporting these findings will be reviewed here and will be discussed in the context of considering mechanisms by which the negative impact of neuroinflammation can be ameliorated.This article is part of a Special Issue entitled SI: Brain and Memory.