Memory consolidation impairment by interleukin-1 beta is associated with changes in hippocampal structural plasticity

SCHIÖTH, HELGI B.; CALFA, GASTÓN; SCIMONELLI, TERESA; HERRERA, GUADALUPE; LASAGA, MERCEDES

BEHAVIOURAL BRAIN RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2019 vol. 1 p. 1 - 12

0166-4328

Pro-inflammatory cytokines, particularly Interleukin-1β(IL-1β), can affect cognitive processes such as learningand memory. The aim of this study was to establish whether the effect of IL-1βon contextual fear memory isassociated with changes in hippocampal structural plasticity. We also studied the effect ofα-melanocyte-sti-mulating hormone (α-MSH), a potent anti-inflammatory and neuro-protective peptide. Different groups of an-imals were implanted bilaterally in dorsal hippocampus (DH). After recovery they were conditioned for con-textual fear memory and received the different treatments (vehicle, IL-1β,α-MSH or IL-1β+α-MSH). Memorywas assessed 24 hs after conditioning and immediately after rats were perfused for dendritic spine analysis. Ourresults show that local hippocampal administration of IL-1βjust after memory encoding induced impairment incontextual memory and a reduction in the total density of CA1 hippocampal dendritic spines, particularly themature ones.α-MSH administration reversed the IL-1βinduced changes. The results suggest that neuro-in-flammation induced by IL-1βinterferes with experience-dependent structural plasticity in DH whereasα-MSHhas a beneficial modulatory role in preventing this effect.