Electrophysiological characterization of expiratory motoneurons in rats submitted to sustained hypoxia

• Grant number: 15/01073-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: May 01, 2015
• End date: December 31, 2018
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: Benedito Honorio Machado
• Grantee: Melina Pires da Silva
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 13/06077-5 - Changes in the neural networks involved with the generation and control of sympathetic and respiratory activities in different experimental models of hypoxia, AP.TEM

Abstract

Studies from our laboratory have documented that hypoxia induces an increase in expiratory activity of rats, which becomes an active process. However, this condition is not due to changes in the electrophysiological properties of ventral medullary expiratory neurons, responsible for the generation of expiration, suggesting that others expiratory neurons could be involved in this change. In this project, we will evaluate whether the final pathway for expiration control, determined by the expiratory motoneurons, are involved in these changes. On the one hand, we intend to investigate the intrinsic electrophysiological membrane properties of these cells under basal conditions and compare them with electrophysiological properties from rats submitted to sustained hypoxia, in which the expiration becomes active. On another hand, molecular biology experiments using single cell RT-qPCR will allow us to evaluate differences in the ion channels genes expressions, which can explain the possible changes in the intrinsic properties of motoneurons in response to hypoxia, and to characterize them using ionic currents records. For this purpose, we will use cellular electrophysiology, essentially, whole cell patch clamp. Microinjections of retrograde tracers in different expiratory muscles will guide us in identifying the cells of interest, as well as to associate intrinsic properties of motoneuron labeled with its medullar lamina. The motoneuron phenotypes will also be analyzed by a neuronal tracer using immunofluorescence techniques. The results to be obtained with this project will help us to understand the mechanisms involved in the changes in the intrinsic properties of motoneurons and their importance to the expiratory muscles activity in sustained hypoxic conditions.

Scientific publications

(4)

(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)

MAGALHAES, KAROLYNE S.; SPILLER, PEDRO F.; DA SILVA, MELINA P.; KUNTZE, LUCIANA B.; PATON, JULIAN F. R.; MACHADO, BENEDITO H.; MORAES, DAVI J. A.. Locus Coeruleus as a vigilance centre for active inspiration and expiration in rats. SCIENTIFIC REPORTS, v. 8, OCT 23 2018. (13/10484-5, 15/01073-7, 17/09071-9, 16/24869-4, 13/06077-5)

MORAES, DAVI J. A.; BONAGAMBA, LENI G. H.; DA SILVA, MELINA P.; PATON, JULIAN F. R.; MACHADO, BENEDITO H.. Role of ventral medullary catecholaminergic neurons for respiratory modulation of sympathetic outflow in rats. SCIENTIFIC REPORTS, v. 7, DEC 4 2017. (13/06077-5, 15/01073-7, 13/10484-5)

MORAES, DAVI J. A.; DA SILVA, MELINA P.; SPILLER, PEDRO F.; MACHADO, BENEDITO H.; PATON, JULIAN F. R.. Purinergic plasticity within petrosal neurons in hypertension. AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, v. 315, n. 5, p. R963-R971, NOV 2018. (15/01073-7, 13/06077-5, 16/24869-4, 13/10484-5)

DE BRITTO, ALAN A.; MAGALHAES, KAROLYNE S.; DA SILVA, MELINA P.; PATON, JULIAN F. R.; MORAES, DAVI J. A.. Active expiratory oscillator regulates nasofacial and oral motor activities in rats. Experimental Physiology, v. 105, n. 2, JAN 2020. (15/01073-7, 13/10484-5, 17/09071-9, 16/24994-3)