Genetic identity and neural circuit connections of aldosterone-sensitive neurons in rat and mouse NTS

• Grant number: 18/04134-5
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Start date: August 30, 2018
• End date: September 08, 2018
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: Eduardo Colombari
• Grantee: Eduardo Colombari
• Visiting researcher: Joel C. Geerling
• Visiting researcher institution: University of Iowa, United States
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Associated research grant: 15/23467-7 - Experimental pathophysiology: role of central mechanisms of the cardiovascular and respiratory control changes induced by experimental hypertension and obesity, AP.TEM

Abstract

Aldosterone infusion into the 4th ventricle (4th V), upstream of the nucleus of the solitary tract (NTS), produces strong 0.3 M NaCl intake. In the present study, we investigated whether aldosterone infusion into the 4th V activates HSD2 neurons, changes renal excretion, or alters blood pressure and cardiovascular reflexes. Chronic infusion of aldosterone (100 ng.h-1) into the 4th V increased daily 0.3 M NaCl intake (up to 44 ± 10, vs. vehicle: 5.6 ± 3.4 ml.24 h-1) and also c-Fos expression in HSD2 neurons in the NTS and in non-HSD2 neurons in the NTS. Natriuresis, diuresis and positive sodium balance were present in rats that ingested 0.3 M NaCl, however, renal excretion was not modified by 4th V aldosterone in rats that had no access to NaCl. 4th V aldosterone also reduced baroreflex sensitivity (-2.8 ± 0.5, vs. vehicle: -5.1 ± 0.9 bpm/mmHg-1) in animals that had sodium available, without changing blood pressure. The results suggest that sodium intake induced by aldosterone infused into the 4th V is associated with activation of NTS neurons, among them the HSD2 neurons. Aldosterone infused into the 4th V in association with sodium intake also impairs baroreflex sensitivity, without changing arterial pressure. (AU)

Scientific publications

(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)

GASPARINI, S.; MELO, M. R.; ANDRADE-FRANZE, G. M. F.; GEERLING, J. C.; MENANI, J. V.; COLOMBARI, E.. Aldosterone infusion into the 4th ventricle produces sodium appetite with baroreflex attenuation independent of renal or blood pressure changes. Brain Research, v. 1698, p. 70-80, NOV 1 2018. (13/00026-0, 15/23467-7, 18/04134-5)