title: Social challenge increases cortisol and hypothalamic monoamine levels in matrinxã (Brycon amazonicus).
abstract: The neural circuitry for social behavior and aggression appears to be evolutionarily conserved across the vertebrate subphylum and involves a complex neural network that includes the hypothalamus as a key structure. In the present study, we evaluated the changes in monoamine levels in the hypothalamus and on serum cortisol and plasma glucose of resident matrinxã (Brycon amazonicus) submitted to a social challenge (introduction of an intruder in their territory). The fight promoted a significant increase in hypothalamic 5-HT, NA and DA levels and on the metabolites 5-HIAA and DOPAC, and decreased 5-HIAA/5-HT and DOPAC/DA ratios in resident fish. Furthermore, an increase in serum cortisol and plasma glucose was also observed after the fight. Resident fish presented a high aggressiveness even with increased 5-HT levels in the hypothalamus. The alteration in hypothalamic monoaminergic activity of matrinxã suggests that this diencephalic region is involved in aggression and stress modulation in fish; however, it does not exclude the participation of other brain areas not tested here.
authors.affiliation: Aquaculture Center of Unesp, University of São Paulo State, Access Road Professor Doutor Paulo Donato Castellane, Jaboticabal, SP, 14884-900, Brazil. carlawolkers@yahoo.com.br.|Faculty of Integrated Sciences of Pontal, Federal University of Uberlândia, 1600 Twenty Street, Ituiutaba, MG, 38304-402, Brazil. carlawolkers@yahoo.com.br.
authors.forename: Carla Patrícia Bejo
authors.initials: CP
authors.lastname: Wolkers
authors.affiliation: Aquaculture Center of Unesp, University of São Paulo State, Access Road Professor Doutor Paulo Donato Castellane, Jaboticabal, SP, 14884-900, Brazil.
authors.forename: Mônica
authors.initials: M
authors.lastname: Serra
authors.affiliation: Aquaculture Center of Unesp, University of São Paulo State, Access Road Professor Doutor Paulo Donato Castellane, Jaboticabal, SP, 14884-900, Brazil.
authors.forename: Elisabeth Criscuolo
authors.initials: EC
authors.lastname: Urbinati
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000374:Aggression; D000588:Amines / Q000378:metabolism*; D000818:Animals; D001522:Behavior, Animal; D001786:Blood Glucose / Q000032:analysis; D060126:Characidae / Q000502:physiology*; D006854:Hydrocortisone / Q000097:blood*; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism; D013312:Stress, Physiological
chemical_list: D000588:Amines; D001786:Blood Glucose; D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D006854:Hydrocortisone
keywords: Aggression; Cortisol; Dopamine; Hypothalamus; Noradrenaline; Serotonin