title: Interactions between serotonin and glutamate-nitric oxide pathways in zebrafish scototaxis.
abstract: NMDA receptors have been implicated in the acute response to stress, possibly mediated the nitric oxide pathway; serotonin has also been implicated in these responses, and has recently been shown to modulate the nitric oxide pathway via 5-HT1 and 5-HT2 receptors. In this work, we compare the effects of NMDA and a 5-HT1A receptor ligands on light/dark preference in adult zebrafish, and investigate whether nitric oxide mediates the effects of such drugs. The noncompetitive NMDA receptor antagonist MK-801 decreased dark preference (scototaxis), while NMDA increased it; the effects of NMDA were completely blocked by pretreatment with the nitric oxide synthase (NOS) antagonist L-NAME. SNP, a nitric oxide donor, produced a bell-shaped dose-response profile on scototaxis. Treatment with 5-HTP increased scototaxis, an effect which was potentiated by pre-treatment with NMDA, but not MK-801, and partially blocked by L-NAME. The 5-HT1A receptor antagonist WAY 100,635 decreased scototaxis, an effect which was completely blocked by L-NAME. These results suggest that tonic NOS inhibition is an important downstream effector of 5-HT1A receptors in the regulation of dark preference behavior in zebrafish, and that NOS is also under phasic independent control by NMDA receptors.
authors.affiliation: Laboratório de Neuroendocrinologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil; Zebrafish Neuroscience Research Consortium, USA.
authors.forename: Anderson Manoel
authors.initials: AM
authors.lastname: Herculano
authors.affiliation: Laboratório de Neuroendocrinologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil.
authors.forename: Bruna
authors.initials: B
authors.lastname: Puty
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Miranda
authors.affiliation: Zebrafish Neuroscience Research Consortium, USA; Departamento de Morfologia e Ciências Fisiológicas, Centro de Ciências Biológicas e da Saúde, Universidade do Estado do Pará, Marabá, PA, Brazil.
authors.forename: Monica Gomes
authors.initials: MG
authors.lastname: Lima
authors.affiliation: Zebrafish Neuroscience Research Consortium, USA; Departamento de Morfologia e Ciências Fisiológicas, Centro de Ciências Biológicas e da Saúde, Universidade do Estado do Pará, Marabá, PA, Brazil. Electronic address: caio.maximino@uepa.br.
authors.forename: Caio
authors.initials: C
authors.lastname: Maximino
mesh_terms: D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000818:Animals; D001007:Anxiety / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D016202:N-Methylaspartate / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D012701:Serotonin / Q000378:metabolism*; D015027:Zebrafish
chemical_list: D020030:Nitric Oxide Donors; D010879:Piperazines; D011725:Pyridines; D009569:Nitric Oxide; D012701:Serotonin; D018698:Glutamic Acid; D016202:N-Methylaspartate; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide; D006916:5-Hydroxytryptophan
keywords: 5-HT(1A) receptor; Glutamate; Nitric oxide; Scototaxis; Serotonin; Zebrafish