title: α-Melanocyte-stimulating hormone (α-MSH) reverses impairment of memory reconsolidation induced by interleukin-1 beta (IL-1 beta) hippocampal infusions.
abstract: Interleukin-1 beta (IL-1β) significantly influences cognitive processes. Treatments which raise the level of IL-1β in the brain impair memory consolidation in contextual fear conditioning. However, the effect of IL-1β on memory reconsolidation has not yet been established. The melanocortin α-melanocyte-stimulating hormone (α-MSH) exerts potent anti-inflammatory actions by antagonizing the effect of proinflammatory cytokines. Five subtypes of melanocortin receptors (MC1R-MC5R) have been identified, of which MC3R and MC4R are predominant in the central nervous system. The present experiments show that the injection of IL-1β (5 ng/0.25 μl) in dorsal hippocampus up to 30 min after re-exposition to the context decreases freezing during the contextual fear test. Impairment of memory reconsolidation was reversed by treatment with α-MSH (0.05 μg/0.25 μl). Administration of the MC4 receptor antagonist HS014 (0.5 μg/0.25 μl) blocked the effect of α-MSH. These results suggest that IL-1β may influence memory reconsolidation and that activation of central MC4R could lead to improve cognitive performance.
authors.affiliation: IFEC CONICET Departamento Farmacología, Facultad de Ciencias Químicas, UNC, Córdoba, Argentina.
authors.forename: Ivana
authors.initials: I
authors.lastname: Machado
authors.forename: Patricia
authors.initials: P
authors.lastname: González
authors.forename: Helgi Birgir
authors.initials: HB
authors.lastname: Schiöth
authors.forename: Mercedes
authors.initials: M
authors.lastname: Lasaga
authors.forename: Teresa Nieves
authors.initials: TN
authors.lastname: Scimonelli
mesh_terms: D000818:Animals; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D053583:Interleukin-1beta / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects*; D010456:Peptides, Cyclic / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D044105:Receptor, Melanocortin, Type 4 / Q000037:antagonists & inhibitors / Q000502:physiology*; D000521:alpha-MSH / Q000494:pharmacology*
chemical_list: C116941:HS014 cyclic peptide; D053583:Interleukin-1beta; D010456:Peptides, Cyclic; D044105:Receptor, Melanocortin, Type 4; D000521:alpha-MSH