RÉSUMÉ
To identify an individual as familiar, rodents form a specific type of memory named social recognition memory. The olfactory bulb (OB) is an important structure for social recognition memory, while the hippocampus recruitment is still controversial. The present study was designed to elucidate the OB and the dorsal hippocampus contribution to the consolidation of social memory. For that purpose, we tested the effect of anisomycin (ANI), which one of the effects is the inhibition of protein synthesis, on the consolidation of social recognition memory. Swiss adult mice with cannulae implanted into the CA1 region of the dorsal hippocampus or into the OB were exposed to a juvenile during 5 min (training session; TR), and once again 1.5 h or 24 h later to test social short-term memory (S-STM) or social long-term memory (S-LTM), respectively. To study S-LTM consolidation, mice received intra-OB or intra-CA1 infusion of saline or ANI immediately, 3, 6 or 18 h after TR. ANI impaired S-LTM consolidation in the OB, when administered immediately or 6h after TR. In the dorsal hippocampus, ANI was amnesic only if administered 3 h after TR. Furthermore, the infusion of ANI in either OB or CA1, immediately after training, did not affect S-STM. Moreover, ANI administered into the OB did not alter the animal's performance in the buried food-finding task. Altogether, our results suggest the consolidation of S-LTM requires both OB and hippocampus participation, although in different time points. This study may help shedding light on the specific roles of the OB and dorsal hippocampus in social recognition memory.
Sujet(s)
Anisomycine/toxicité , Hippocampe/effets des médicaments et des substances chimiques , Troubles de la mémoire/induit chimiquement , Inhibiteurs de la synthèse d'acide nucléique/toxicité , Bulbe olfactif/effets des médicaments et des substances chimiques , /effets des médicaments et des substances chimiques , Comportement social , Facteurs âges , Animaux , Conditionnement psychologique/effets des médicaments et des substances chimiques , Modèles animaux de maladie humaine , Peur/psychologie , Comportement alimentaire/effets des médicaments et des substances chimiques , Mâle , Souris , Temps de réaction/effets des médicaments et des substances chimiques , Statistique non paramétrique , Facteurs tempsRÉSUMÉ
BACKGROUND: The pathogenesis of atopic dermatitis (AD) is still not completely understood. AD is characterized by the presence of clinical symptoms of both IgE antibody-mediated immediate hypersensitivity and specific T lymphocyte-mediated delayed hypersensitivity. OBJECTIVE: To evaluate the immunological mechanisms involved in children with acute AD lesions. MATERIAL AND METHODS: Ten children with acute AD lesions and 10 non-atopic controls were studied. Total IgE was measured by immunoassay. T cell marker expression (CD3, CD4, CD8, cutaneous lymphocyte-associated antigen [CLA]) and cytokine production (interferon [IFN]-gamma, interleukin [IL]-13) were analyzed in peripheral blood mononuclear cells by flow cytometry. RESULTS: In children with AD the percentage of CD3+ cells (p = 0.015) increased while that of CD8+ cells (p = 0.023) decreased, with no differences in CLA expression. We found increased IL-13 production in CD3+ cells (p = 0.01) and CD3+CD4+ (p = 0.001) cells with no difference in IFN-gamma. Total IgE was significantly higher in patients with AD (p = 0.01). Comparison of IL-13 production in CD4+ cells categorized by total IgE level showed that IL-13 production was significantly increased in subjects with a higher IgE level. CONCLUSION: Peripheral blood from children with AD showed an increase in IgE levels and a Th2 pattern. There was a correlation between IL-13 production and total IgE levels.