Lipopolysaccharide induces memory-processing deficits in day-old chicks

Recent evidence has demonstrated that immune activation can result in cogni tive deficits due to the actions of the proinflammatory cytokines. These se ries of studies examined the effects of peripheral administration of lipopo lysaccharide (LPS) on the memory processes of day-old chicks trained on a s ingle-trial passive-avoidance task. LPS impaired performance in a dose- and time-dependent manner. Maximal impairment was produced by a dose of 2.5-mg /kg LPS administered 60 min prior to training. Retention tests revealed tha t deficits in memory processing appeared between 10 and 20 min posttraining . These results demonstrate an inhibitory effect of LPS on memory processin g at the transition point from short-term memory to intermediate-term memor y. (C) 2001 Elsevier Science Inc. All rights reserved.