Nitric oxide as a modulator of electrical activity in magnocellular neurons of the rat supraoptic nucleus

• Grant number: 12/19750-7
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2013
• End date: January 31, 2015
• Field of knowledge: Biological Sciences - Biophysics - Cellular Biophysics
• Principal Investigator: Wamberto Antonio Varanda
• Grantee: Wamberto Antonio Varanda
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The role played by Nitric Oxide (NO) as a neurotransmitter in controlling the electrical activity of Magnocellular Neurons of the SON (MNCs) was postulated after reports that hyperosmotic stimulation of these cells lead to an increase in the expression of nitric oxide synthase (NOS) mRNA and of oxytocin (OT) and vasopressin (VP) secretions. Several reports show that NO can act both indirectly and directly upon the MNCs. Indirectly, by potentiating inhibitory synaptic inputs, and directly by acting on specific ionic currents which lead to a decrease in the firing frequency of the MNCs. As a consequence of this latter effect, there is a decrease in the secretion of OT and VP. Moreover, channels from the TRPV (transient receptor potencial vaniloid) family seems to work as osmomechano receptors and also able to affect the electrical activity of the MNCs. In view of these findings this project aims at investigating the effects of NO upon these regulatory pathways of the MNCs, by using electrophysiological techniques (patch clamp) in slices and isolated cells of the SON, as well as current molecular biology techniques (RT-PCR) in order to identify the molecular characteristics (OT and/or VP) of the neurons under investigation. Intracellular ionic activities and signaling molecules will be detected with the use of specific fluorescent dyes and confocal microscopy, in order to gain insight on the biochemical regulatory pathways involved in the control of the MNCs activity. (AU)

Scientific publications

(7)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MORAES, DAVI J. A.; DA SILVA, MELINA P.; BONAGAMBA, LENI G. H.; MECAWI, ANDRE S.; ZOCCAL, DANIEL B.; ANTUNES-RODRIGUES, JOSE; VARANDA, WAMBERTO A.; MACHADO, BENEDITO H.. Electrophysiological Properties of Rostral Ventrolateral Medulla Presympathetic Neurons Modulated by the Respiratory Network in Rats. JOURNAL OF NEUROSCIENCE, v. 33, n. 49, p. 19223-19237, DEC 4 2013. (12/19750-7)

M.P. DA SILVA; P.L. CEDRAZ-MERCEZ; W.A. VARANDA. Effects of nitric oxide on magnocellular neurons of the supraoptic nucleus involve multiple mechanisms. Brazilian Journal of Medical and Biological Research, v. 47, n. 2, p. 90-100, 2014-02-00. (12/19750-7, 12/01859-2)

DA SILVA, M. P.; MERINO, R. M.; MECAWI, A. S.; MORAES, D. J.; VARANDA, W. A.. In vitro differentiation between oxytocin- and vasopressin-secreting magnocellular neurons requires more than one experimental criterion. Molecular and Cellular Endocrinology, v. 400, n. C, p. 102-111, JAN 15 2015. (12/19750-7)

ZANUTTO BASSETTO JUNIOR, CARLOS ALBERTO; GUSHIKEN PASSIANOTO, LUANA VITORINO; PEREZ GONZALEZ, EDUARDO RENE; VARANDA, WAMBERTO ANTONIO. Benzenesulfonamides act as open-channel blockers on K(V)3.1 potassium channel. Amino Acids, v. 51, n. 2, p. 355-364, FEB 2019. (12/19750-7, 13/24487-6)

J.L. DE DEUS; A.L.A. DAGOSTIN; W.A. VARANDA. Nitric oxide modulates ATP-evoked currents in mouse Leydig cells. Brazilian Journal of Medical and Biological Research, v. 51, n. 5, 2018-03-15. (12/19750-7)

ZANUTTO BASSETTO JUNIOR, CARLOS ALBERTO; VARANDA, WAMBERTO ANTONIO; PEREZ GONZALEZ, EDUARDO RENE. 4-Chloro-3-nitro-N-butylbenzenesulfonamide acts on K(V)3.1 channels by an open-channel blocker mechanism. Amino Acids, v. 49, n. 11, p. 1895-1906, NOV 2017. (13/24487-6, 12/19750-7)

DA SILVA, MELINA PIRES; DE ALMEIDA MORAES, DAVI JOSE; MECAWI, ANDRE DE SOUZA; RODRIGUES, JOSE ANTUNES; VARANDA, WAMBERTO ANTONIO. Nitric Oxide Modulates HCN Channels in Magnocellular Neurons of the Supraoptic Nucleus of Rats by an S-Nitrosylation-Dependent Mechanism. JOURNAL OF NEUROSCIENCE, v. 36, n. 44, p. 11320-11330, NOV 2 2016. (12/19750-7, 13/10484-5)