title: Peripheral bacterial endotoxin administration triggers both memory consolidation and reconsolidation deficits in mice.
abstract: Peripherally administered inflammatory stimuli, such as lipopolysaccharide (LPS), induce the synthesis and release of proinflammatory cytokines and chemokines in the periphery and the central nervous system, and trigger a variety of neurobiological responses. Indeed, prior reports indicate that peripheral LPS administration in rats disrupts contextual fear memory consolidation processes, potentially due to elevated cytokine expression. We used a similar, but partially olfaction-based, contextual fear conditioning paradigm to examine the effects of LPS on memory consolidation and reconsolidation in mice. Additionally, interleukin-1β (IL-1β), brain-derived neurotrophic factor (BDNF), and zinc finger (Zif)-268 mRNA expression in the hippocampus and the cortex, along with peripheral cytokines and chemokines, were assessed. As hypothesized, LPS administered immediately or 2 h, but not 12 h, post-training impaired memory consolidation processes that support the storage of the conditioned contextual fear memory. Additionally, as hypothesized, LPS administered immediately following the fear memory trace reactivation session impaired memory reconsolidation processes. Four hours post-injection, both central cytokine and peripheral cytokine and chemokine levels were heightened in LPS-treated animals, with a simultaneous decrease in BDNF, but not Zif-268, mRNA. Collectively, these data reinforce prior work showing LPS- and cytokine-related effects on memory consolidation, and extend this work to memory reconsolidation.
authors: Department of Psychology, Texas Christian University, Fort Worth, TX 76129, USA.
authors: Dinko
authors: D
authors: Kranjac
authors: Kristina A
authors: KA
authors: McLinden
authors: Lauren E
authors: LE
authors: Deodati
authors: Mauricio R
authors: MR
authors: Papini
authors: Michael J
authors: MJ
authors: Chumley
authors: Gary W
authors: GW
authors: Boehm
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001923:Brain Chemistry / Q000187:drug effects; D019208:Brain-Derived Neurotrophic Factor / Q000096:biosynthesis; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D018925:Chemokines / Q000096:biosynthesis; D003216:Conditioning, Operant / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis; D004192:Discrimination, Psychological / Q000187:drug effects; D051766:Early Growth Response Protein 1 / Q000096:biosynthesis; D004731:Endotoxins / Q000494:pharmacology*; D005239:Fear / Q000523:psychology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D053583:Interleukin-1beta / Q000096:biosynthesis; D007858:Learning / Q000187:drug effects; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced* / Q000523:psychology*; D051379:Mice; D008810:Mice, Inbred C57BL; D060888:Real-Time Polymerase Chain Reaction; D015431:Weight Loss / Q000187:drug effects
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D018925:Chemokines; D016207:Cytokines; D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; D004731:Endotoxins; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; C044101:endotoxin, Escherichia coli