| 1. |
- Herrera, Guadalupe, et al.
(författare)
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Memory consolidation impairment induced by Interleukin-1 beta is associated with changes in hippocampal structural plasticity
- 2019
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Ingår i: Behavioural Brain Research. - : ELSEVIER SCIENCE BV. - 0166-4328 .- 1872-7549. ; 370
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Tidskriftsartikel (refereegranskat)abstract
- Pro-inflammatory cytokines, particularly Interleukin-1 beta (IL-1 beta), can affect cognitive processes such as learning and memory. The aim of this study was to establish whether the effect of IL-1 beta on contextual fear memory is associated with changes in hippocampal structural plasticity. We also studied the effect of alpha-melanocyte-stimulating hormone (alpha-MSH), a potent anti-inflammatory and neuro-protective peptide. Different groups of animals were implanted bilaterally in dorsal hippocampus (DH). After recovery they were conditioned for contextual fear memory and received the different treatments (vehicle, IL-1 beta, alpha-MSH or IL-1 beta + alpha-MSH). Memory was assessed 24 hs after conditioning and immediately after rats were perfused for dendritic spine analysis. Our results show that local hippocampal administration of IL-1 beta just after memory encoding induced impairment in contextual memory and a reduction in the total density of CA1 hippocampal dendritic spines, particularly the mature ones. alpha-MSH administration reversed the IL-1 beta induced changes. The results suggest that neuro-inflammation induced by IL-1 beta interferes with experience-dependent structural plasticity in DH whereas alpha-MSH has a beneficial modulatory role in preventing this effect.
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| 2. |
- Machado, Ivana, et al.
(författare)
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IL-1 beta reduces GluAl phosphorylation and its surface expression during memory reconsolidation and cc-melanocyte-stimulating hormone can modulate these effects
- 2018
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Ingår i: Neuropharmacology. - : Elsevier. - 0028-3908 .- 1873-7064. ; 128, s. 314-323
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Tidskriftsartikel (refereegranskat)abstract
- Pro-inflammatory cytokines can affect cognitive processes such as learning and memory. Particularly, interleukin-beta (IL-beta) influences hippocampus-dependent memories. We previously reported that administration of IL-1 beta in dorsal hippocampus impaired contextual fear memory reconsolidation. This effect was reversed by the melanocortin alpha-melanocyte-stimulating hormone (a-MSH). Our results also demonstrated that IL-1 beta produced a significant decrease in glutamate release from dorsal hippo campus synaptosomes after reactivation of the fear memory. Therefore, we investigated whether IL-beta administration can affect GIuA1 AMPA subunit phosphorylation, surface expression, and total expression during reconsolidation of a contextual fear memory. Also, we studied the modulatory effect of alpha-MSH. We found that IL-beta reduced phosphorylation of this subunit at Serine 831 and Serine 845 60 min after contextual fear memory reactivation. The intrahippocampal administration of IL-beta after memory reactivation also induced a decrease in surface expression and total expression of GIuA1. alpha-MSH prevented the effect of IL-beta on GIuAI phosphorylation in Serine 845, but not in Serine 831. Moreover, treatment with alpha-MSH also prevented the effect of the cytokine on GluAl surface and total expression after memory reactivation. Our results demonstrated that IL-beta regulates phosphorylation of GIuAI and may thus play an important role in modulation of AMPAR function and synaptic plasticity in the brain. These findings further illustrate the importance of IL-beta in cognition processes dependent on the hippocampus, and also reinforced the fact that alpha-MSH can reverse IL-1 beta effects on memory reconsolidation. (C) 2017 Elsevier Ltd. All rights reserved.
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| 3. |
- Machado, Ivana, et al.
(författare)
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Interleukin-1 beta-induced memory reconsolidation impairment is mediated by a reduction in glutamate release and zif268 expression and alpha-melanocyte-stimulating hormone prevented these effects
- 2015
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Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 46, s. 137-146
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Tidskriftsartikel (refereegranskat)abstract
- The immune system is an important modulator of learning, memory and neural plasticity. Interleukin 1 13 (IL-1 beta), a pro-inflammatory cytokine, significantly affects several cognitive processes. Previous studies by our group have demonstrated that intrahippocampal administration of IL-1 beta impairs reconsolidation of contextual fear memory. This effect was reversed by the melanocortin alpha-melanocyte-stimulating hormone (alpha-MSH). The mechanisms underlying the effect of IL-1 beta on memory reconsolidation have not yet been established. Therefore, we examined the effect of IL-1 beta on glutamate release, ERK phosphorylation and the activation of the transcription factor zinc finger- 268 (zif268) during reconsolidation. Our results demonstrated that IL-1 beta induced a significant decrease of glutamate release after reactivation of the fear memory and this effect was related to calcium concentration in hippocampal synaptosomes. IL-1 beta also reduced ERK phosphorylation and zif268 expression in the hippocampus. Central administration of a-MSH prevented the decrease in glutamate release, ERK phosphorylation and zif268 expression induced by IL-1 beta. Our results establish possible mechanisms involved in the detrimental effect of IL-1 beta on memory reconsolidation and also indicate that a-MSH may exert a beneficial modulatory role in preventing IL-1 beta effects.
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