title: The Antidepressant-Like Effect of Fish Oil: Possible Role of Ventral Hippocampal 5-HT1A Post-synaptic Receptor.
abstract: The pathophysiology of depression is not completely understood; nonetheless, numerous studies point to serotonergic dysfunction as a possible cause. Supplementation with fish oil rich docosahexaenoic (DHA) and eicosapentaenoic acids (EPA) during critical periods of development produces antidepressant effects by increasing serotonergic neurotransmission, particularly in the hippocampus. In a previous study, the involvement of 5-HT1A receptors was demonstrated and we hypothesized that fish oil supplementation (from conception to weaning) alters the function of post-synaptic hippocampal 5-HT1A receptors. To test this hypothesis, female rats were supplemented with fish oil during habituation, mating, gestation, and lactation. The adult male offspring was maintained without supplementation until 3 months of age, when they were subjected to the modified forced swimming test (MFST) after infusion of vehicle or the selective 5-HT1A antagonist, WAY100635, and frequency of swimming, immobility, and climbing was recorded for 5 min. After the behavioral test, the hippocampi were obtained for quantification of serotonin (5-HT) and its metabolite, 5-hydroxyindoleacetic acid (5-HIAA) and for 5-HT1A receptor expression by Western blotting analysis. Fish oil-supplemented offspring displayed less depressive-like behaviors in the MFST reflected by decreased immobility and increased swimming and higher 5-HT hippocampal levels. Although there was no difference in the expression of hippocampal 5-HT1A receptors, intra-hippocampal infusion of a sub-effective dose of 8-OH-DPAT enhanced the antidepressant effect of fish oil in supplemented animals. In summary, the present findings suggest that the antidepressant-like effects of fish oil supplementation are likely related to increased hippocampal serotonergic neurotransmission and sensitization of hippocampal 5-HT1A receptors.
authors.affiliation: Laboratório de Neurofisiologia, Departamento de Fisiologia, Universidade Federal do Paraná, Curitiba, PR, 81531-990, Brazil.
authors.forename: Bruno
authors.initials: B
authors.lastname: Carabelli
authors.forename: Ana Marcia
authors.initials: AM
authors.lastname: Delattre
authors.forename: Claudia
authors.initials: C
authors.lastname: Pudell
authors.forename: Marco Aurélio
authors.initials: MA
authors.lastname: Mori
authors.forename: Deborah
authors.initials: D
authors.lastname: Suchecki
authors.forename: Ricardo B
authors.initials: RB
authors.lastname: Machado
authors.forename: Daniel Paulino
authors.initials: DP
authors.lastname: Venancio
authors.forename: Sílvia Regina
authors.initials: SR
authors.lastname: Piazzetta
authors.forename: Ivilim
authors.initials: I
authors.lastname: Hammerschmidt
authors.forename: Sílvio M
authors.initials: SM
authors.lastname: Zanata
authors.forename: Marcelo M S
authors.initials: MM
authors.lastname: Lima
authors.forename: Janaína Menezes
authors.initials: JM
authors.lastname: Zanoveli
authors.forename: Anete Curte
authors.initials: AC
authors.lastname: Ferraz
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005395:Fish Oils / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D007103:Immobilization; D008297:Male; D017208:Rats, Wistar; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D013550:Swimming; D013569:Synapses / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000928:Antidepressive Agents; D005395:Fish Oils; D044282:Receptor, Serotonin, 5-HT1A