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De Luca LA, Laurin M, Menani JV. Control of fluid intake in dehydrated rats and evolution of sodium appetite. Physiol Behav 2024; 284:114642. [PMID: 39032667 DOI: 10.1016/j.physbeh.2024.114642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 07/04/2024] [Accepted: 07/17/2024] [Indexed: 07/23/2024]
Abstract
The objective of the present work is to examine from a new perspective the existence of causal factors not predicted by the classical theory that thirst and sodium appetite are two distinct motivations. For example, we ask why water deprivation induces sodium appetite, thirst is not "water appetite", and intracellular dehydration potentially causes sodium appetite. Contrary to the classical theory, we suggest that thirst first, and sodium appetite second, designate a temporal sequence underlying the same motivation. The single motivation becomes an "intervenient variable" a concept borrowed from the literature, fully explained in the text, between causes of dehydration (extracellular, intracellular, or both together), and respective behavioral responses subserved by hindbrain-dependent inhibition (e.g., lateral parabrachial nucleus) and forebrain facilitation (e.g., angiotensin II). A corollary is homology between rat sodium appetite and marine teleost thirst-like motivation that we name "protodipsia". The homology argument rests on similarities between behavior (salty water intake) and respective neuroanatomical as well as functional mechanisms. Tetrapod origin in a marine environment provides additional support for the homology. The single motivation hypothesis is also consistent with ingestive behaviors in nature given similarities (e.g., thirst producing brackish water intake) between the behavior of the laboratory rat and wild animals, rodents included. The hypotheses of single motivation and homology might explain why hyperosmotic rats, or eventually any other hyperosmotic tetrapod, shows paradoxical signs of sodium appetite. They might also explain how ingestive behaviors determined by dehydration and subserved by hindbrain inhibitory mechanisms contributed to tetrapod transition from sea to land.
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Affiliation(s)
- Laurival A De Luca
- Department of Physiology & Pathology, School of Dentistry, São Paulo State University (UNESP), 14801-903 Araraquara, São Paulo, Brazil.
| | - Michel Laurin
- CR2P, UMR 7207, CNRS/MNHN/SU, Muséum National d'Histoire Naturelle, Bâtiment de Géologie, CP 48, F-75231 Paris cedex 05, France
| | - José Vanderlei Menani
- Department of Physiology & Pathology, School of Dentistry, São Paulo State University (UNESP), 14801-903 Araraquara, São Paulo, Brazil
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Sodium Homeostasis, a Balance Necessary for Life. Nutrients 2023; 15:nu15020395. [PMID: 36678265 PMCID: PMC9862583 DOI: 10.3390/nu15020395] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Body sodium (Na) levels must be maintained within a narrow range for the correct functioning of the organism (Na homeostasis). Na disorders include not only elevated levels of this solute (hypernatremia), as in diabetes insipidus, but also reduced levels (hyponatremia), as in cerebral salt wasting syndrome. The balance in body Na levels therefore requires a delicate equilibrium to be maintained between the ingestion and excretion of Na. Salt (NaCl) intake is processed by receptors in the tongue and digestive system, which transmit the information to the nucleus of the solitary tract via a neural pathway (chorda tympani/vagus nerves) and to circumventricular organs, including the subfornical organ and area postrema, via a humoral pathway (blood/cerebrospinal fluid). Circuits are formed that stimulate or inhibit homeostatic Na intake involving participation of the parabrachial nucleus, pre-locus coeruleus, medial tuberomammillary nuclei, median eminence, paraventricular and supraoptic nuclei, and other structures with reward properties such as the bed nucleus of the stria terminalis, central amygdala, and ventral tegmental area. Finally, the kidney uses neural signals (e.g., renal sympathetic nerves) and vascular (e.g., renal perfusion pressure) and humoral (e.g., renin-angiotensin-aldosterone system, cardiac natriuretic peptides, antidiuretic hormone, and oxytocin) factors to promote Na excretion or retention and thereby maintain extracellular fluid volume. All these intake and excretion processes are modulated by chemical messengers, many of which (e.g., aldosterone, angiotensin II, and oxytocin) have effects that are coordinated at peripheral and central level to ensure Na homeostasis.
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Callera JC, De Luca LA, Menani JV. Involvement of V1-type vasopressin receptors on NaCl intake by hyperosmotic rats treated with muscimol in the lateral parabrachial nucleus. Neurosci Lett 2022; 778:136601. [DOI: 10.1016/j.neulet.2022.136601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/25/2022] [Accepted: 03/26/2022] [Indexed: 11/29/2022]
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NODA M, MATSUDA T. Central regulation of body fluid homeostasis. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2022; 98:283-324. [PMID: 35908954 PMCID: PMC9363595 DOI: 10.2183/pjab.98.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Extracellular fluids, including blood, lymphatic fluid, and cerebrospinal fluid, are collectively called body fluids. The Na+ concentration ([Na+]) in body fluids is maintained at 135-145 mM and is broadly conserved among terrestrial animals. Homeostatic osmoregulation by Na+ is vital for life because severe hyper- or hypotonicity elicits irreversible organ damage and lethal neurological trauma. To achieve "body fluid homeostasis" or "Na homeostasis", the brain continuously monitors [Na+] in body fluids and controls water/salt intake and water/salt excretion by the kidneys. These physiological functions are primarily regulated based on information on [Na+] and relevant circulating hormones, such as angiotensin II, aldosterone, and vasopressin. In this review, we discuss sensing mechanisms for [Na+] and hormones in the brain that control water/salt intake behaviors, together with the responsible sensors (receptors) and relevant neural pathways. We also describe mechanisms in the brain by which [Na+] increases in body fluids activate the sympathetic neural activity leading to hypertension.
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Affiliation(s)
- Masaharu NODA
- Homeostatic Mechanism Research Unit, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa, Japan
- Correspondence should be addressed to: Homeostatic Mechanism Research Unit, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama, Kanagawa 226-8503, Japan (e-mail: )
| | - Takashi MATSUDA
- Homeostatic Mechanism Research Unit, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa, Japan
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Callera JC, De Luca LA, Menani JV. Mineral preference in rats treated with muscimol into the lateral parabrachial nucleus. Neurosci Lett 2020; 731:134989. [PMID: 32380141 DOI: 10.1016/j.neulet.2020.134989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 04/01/2020] [Accepted: 04/14/2020] [Indexed: 10/24/2022]
Abstract
Injection of muscimol, a GABAA receptor agonist, into the lateral parabrachial nucleus (LPBN) induces 0.3 M NaCl intake in rats. In the present work, we investigated whether such an effect applies to hypertonic (0.3 M) mineral solutions in general or is selective to sodium solutions in a 240 min intake test. Muscimol injection (0.5 nmol/0.2 μL) compared to vehicle injection into the LPBN of adult hydrated rats produced a preferential ingestion of 0.3 M NaCl (25.3 ± 10.2 mL) followed by a 0.3 M NaHCO3 intake (11.7 ± 5.6 mL), with no significant effect on water, KCl and CaCl2 intake. Only the effect of muscimol on NaCl intake (19.0 ± 10.4 mL) persisted in cell-dehydrated rats, with hardly any effect on water or other mineral solutions. The results suggest that the LPBN controls the ingestion of hypertonic NaCl and NaHCO3. They also suggest a selective mechanisms involving the LPBN to check hypertonic sodium intake.
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Affiliation(s)
- João Carlos Callera
- Department of Basic Sciences, School of Dentistry, Sao Paulo State University (UNESP), Rodovia Marechal Rondom, Km 527, 16018-805, Araçatuba, SP, Brazil.
| | | | - José Vanderlei Menani
- Department of Physiology and Pathology, School of Dentistry, UNESP, Araraquara, SP, Brazil
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Polli FDS, Gomes JN, Ferreira HS, Santana RC, Fregoneze JB. Inhibition of salt appetite in sodium-depleted rats by carvacrol: Involvement of noradrenergic and serotonergic pathways. Eur J Pharmacol 2019; 854:119-127. [PMID: 30986399 DOI: 10.1016/j.ejphar.2019.04.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 03/29/2019] [Accepted: 04/11/2019] [Indexed: 12/17/2022]
Abstract
Carvacrol, a monoterpene phenol present in the essential oil of oregano, possesses several biological properties, such as antioxidant, anti-inflammatory, anxiolytic, anticonvulsive and antinociceptive. In vitro studies have shown that carvacrol inhibits serotonin, noradrenaline and dopamine transporters and the enzymes monoamine oxidase-A and B. Different brain functions are controlled by monoamines, including cardiovascular control, thirst and sodium appetite. In the present study we investigated the effects of intracerebroventricular (i.c.v.) injection of carvacrol on sodium appetite, and the participation of brain serotonergic and noradrenergic pathways on carvacrol effects. Neuronal activation in homeostasis-related brain areas induced by i.c.v. injection of carvacrol was also evaluated. Carvacrol dose-dependently inhibited hypertonic saline intake (1.5%) in sodium-depleted rats, and this antinatriorexigenic effect was reduced by brain serotonergic depletion and by alpha-adrenergic blockade. Furthermore, i.c.v. injections of carvacrol significantly increased the neuronal activation in brain areas involved in the control of salt appetite, such as MnPO, OVLT, PVN, SON, CeA and MeA. Taken together, our data show that carvacrol presents antinatriorexigenic activity through serotonin and noradrenaline pathways within brain circuits involved in the modulation of the body fluid homeostasis.
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Affiliation(s)
- Filip de Souza Polli
- Department of Physiology, Health Sciences Institute, Federal University of Bahia, 40110-100, Salvador, Bahia, Brazil.
| | - Jefferson Novaes Gomes
- Department of Physiology, Health Sciences Institute, Federal University of Bahia, 40110-100, Salvador, Bahia, Brazil
| | - Hilda Silva Ferreira
- Life Sciences Department, Bahia State University, 41195-001, Salvador, Bahia, Brazil
| | - Rejane Conceição Santana
- Department of Physiology, Health Sciences Institute, Federal University of Bahia, 40110-100, Salvador, Bahia, Brazil
| | - Josmara Bartolomei Fregoneze
- Department of Physiology, Health Sciences Institute, Federal University of Bahia, 40110-100, Salvador, Bahia, Brazil
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Anesio A, Barbosa SP, De Luca LA, de Paula PM, Colombari DSA, Colombari E, Andrade CAF, Menani JV. Central muscarinic and LPBN mechanisms on sodium intake. Brain Res Bull 2018; 144:14-20. [PMID: 30391542 DOI: 10.1016/j.brainresbull.2018.10.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 10/25/2018] [Accepted: 10/30/2018] [Indexed: 11/28/2022]
Abstract
Central cholinergic activation stimulates water intake, but also NaCl intake when the inhibitory mechanisms are blocked with injections of moxonidine (α2 adrenergic/imidazoline agonist) into the lateral parabrachial nucleus (LPBN). In the present study, we investigated the involvement of central M1 and M2 muscarinic receptors on NaCl intake induced by pilocarpine (non-selective muscarinic agonist) intraperitoneally combined with moxonidine into the LPBN or by muscimol (GABAA agonist) into the LPBN. Male Holtzman rats with stainless steel cannulas implanted bilaterally in the LPBN and in the lateral ventricle were used. Pirenzepine (M1 muscarinic antagonist, 1 nmol/1 μl) or methoctramine (M2 muscarinic antagonist, 50 nmol/1 μL) injected intracerebroventricularly (i.c.v.) reduced 0.3 M NaCl and water intake in rats treated with pilocarpine (0.1 mg/100 g of body weight) injected intraperitoneally combined with moxonidine (0.5 nmol/0.2 μL) into the LPBN. In rats treated with muscimol (0.5 nmol/0.2 μL) into the LPBN, methoctramine i.c.v. also reduced 0.3 M NaCl and water intake, however, pirenzepine produced no effect. The results suggest that M1 and M2 muscarinic receptors activate central pathways involved in the control of water and sodium intake that are under the influence of the LPBN inhibitory mechanisms.
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Affiliation(s)
- Augusto Anesio
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University - UNESP, Araraquara, SP, Brazil
| | - Silas Pereira Barbosa
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University - UNESP, Araraquara, SP, Brazil
| | - Laurival A De Luca
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University - UNESP, Araraquara, SP, Brazil
| | - Patrícia Maria de Paula
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University - UNESP, Araraquara, SP, Brazil
| | - Débora S A Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University - UNESP, Araraquara, SP, Brazil
| | - Eduardo Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University - UNESP, Araraquara, SP, Brazil
| | - Carina A F Andrade
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University - UNESP, Araraquara, SP, Brazil
| | - José V Menani
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University - UNESP, Araraquara, SP, Brazil.
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Roncari CF, David RB, De Paula PM, Colombari DS, De Luca Jr. LA, Colombari E, Menani JV. The lateral parabrachial nucleus and central angiotensinergic mechanisms in the control of sodium intake induced by different stimuli. Behav Brain Res 2017. [DOI: 10.1016/j.bbr.2017.06.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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9
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Rapid stimulation of sodium intake combining aldosterone into the 4th ventricle and the blockade of the lateral parabrachial nucleus. Neuroscience 2017; 346:94-101. [DOI: 10.1016/j.neuroscience.2017.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 01/04/2017] [Accepted: 01/04/2017] [Indexed: 12/17/2022]
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10
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Lateral parabrachial nucleus and opioid mechanisms of the central nucleus of the amygdala in the control of sodium intake. Behav Brain Res 2017; 316:11-17. [DOI: 10.1016/j.bbr.2016.08.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 08/11/2016] [Accepted: 08/16/2016] [Indexed: 11/21/2022]
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11
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David RB, Roncari CF, Lauar MR, Vendramini RC, Antunes-Rodrigues J, Menani JV, De Luca LA. Sodium intake, brain c-Fos protein and gastric emptying in cell-dehydrated rats treated with methysergide into the lateral parabrachial nucleus. Physiol Behav 2015; 151:111-20. [DOI: 10.1016/j.physbeh.2015.07.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 06/11/2015] [Accepted: 07/10/2015] [Indexed: 10/23/2022]
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Importance of the central nucleus of the amygdala on sodium intake caused by deactivation of lateral parabrachial nucleus. Brain Res 2015; 1625:238-45. [DOI: 10.1016/j.brainres.2015.08.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 08/19/2015] [Accepted: 08/30/2015] [Indexed: 11/20/2022]
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Gasparini S, Andrade-Franzé GMF, Gomide JMC, Andrade CAF, De Luca LA, Colombari DSA, De Paula PM, Colombari E, Menani JV. Sodium intake combining cholinergic activation and noradrenaline into the lateral parabrachial nucleus. Neuroscience 2015; 300:229-37. [PMID: 25977166 DOI: 10.1016/j.neuroscience.2015.04.059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 04/17/2015] [Accepted: 04/25/2015] [Indexed: 11/26/2022]
Abstract
The administration of cholinergic agonists like pilocarpine intraperitoneally (i.p.) or carbachol intracerebroventricularly (i.c.v.) induces water, but non significant hypertonic NaCl intake. These treatments also produce pressor responses, which may inhibit sodium intake. Noradrenaline (NOR) acting on α2-adrenoceptors in the lateral parabrachial nucleus (LPBN) deactivates inhibitory mechanisms increasing fluid depletion-induced sodium intake. In the present study, we investigated: (1) water and 1.8% NaCl intake in rats treated with pilocarpine i.p. or carbachol i.c.v. combined with NOR into the LPBN; (2) if inhibitory signals from cardiovascular receptors are blocked by NOR in the LPBN. Male Holtzman rats with stainless steel guide-cannulas implanted in the lateral ventricle and bilaterally in the LPBN were used. Bilateral injections of NOR (80nmol/0.2μl) into the LPBN decreased water intake (0.8±0.3, vs. saline (SAL): 2.9±0.3ml/180min) induced by pilocarpine (1mg/kg of body weight) i.p., without changing 1.8% NaCl intake (0.8±2.4, vs. SAL: 0.5±0.3ml/180min). Prazosin (1mg/kg of body weight) i.p. blocked pressor responses and increased water and 1.8% NaCl intake (6.3±1.7 and 14.7±3.5ml/180min, respectively) in rats treated with pilocarpine combined with NOR into the LPBN. Prazosin i.p. also increased 1.8% NaCl intake in rats treated with carbachol i.c.v combined with NOR into the LPBN. The results suggest that different signals inhibit sodium intake in rats treated with cholinergic agonists, among them those produced by increases of arterial pressure that are not efficiently deactivated by NOR acting in the LPBN.
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Affiliation(s)
- S Gasparini
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil
| | - G M F Andrade-Franzé
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil
| | - J M C Gomide
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil
| | - C A F Andrade
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil
| | - L A De Luca
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil
| | - D S A Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil
| | - P M De Paula
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil
| | - E Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil
| | - J V Menani
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, UNESP, Araraquara, SP, Brazil.
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Davern PJ. A role for the lateral parabrachial nucleus in cardiovascular function and fluid homeostasis. Front Physiol 2014; 5:436. [PMID: 25477821 PMCID: PMC4235290 DOI: 10.3389/fphys.2014.00436] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 10/26/2014] [Indexed: 11/13/2022] Open
Abstract
The lateral parabrachial nucleus (LPBN) is located in an anatomical position that enables it to perform a critical role in relaying signals related to the regulation of fluid and electrolyte intake and cardiovascular function from the brainstem to the forebrain. Early neuroanatomical studies have described the topographic organization of blood pressure sensitive neurons and functional studies have demonstrated a major role for the LPBN in regulating cardiovascular function, including blood pressure, in response to hemorrhages, and hypovolemia. In addition, inactivation of the LPBN induces overdrinking of water in response to a range of dipsogenic treatments primarily, but not exclusively, those associated with endogenous centrally acting angiotensin II. Moreover, treatments that typically cause water intake stimulate salt intake under some circumstances particularly when serotonin receptors in the LPBN are blocked. This review explores the expanding body of evidence that underlies the complex neural network within the LPBN influencing salt appetite, thirst and the regulation of blood pressure. Importantly understanding the interactions among neurons in the LPBN that affect fluid balance and cardiovascular control may be critical to unraveling the mechanisms responsible for hypertension.
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Affiliation(s)
- Pamela J Davern
- Neuropharmacology Laboratory, Baker IDI Heart and Diabetes Institute Melbourne, VIC, Australia
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Andrade CAF, Andrade-Franzé GMF, De Paula PM, De Luca LA, Menani JV. Role of α2-adrenoceptors in the lateral parabrachial nucleus in the control of body fluid homeostasis. Braz J Med Biol Res 2014; 47:11-8. [PMID: 24519089 PMCID: PMC3932968 DOI: 10.1590/1414-431x20133308] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 10/15/2013] [Indexed: 12/03/2022] Open
Abstract
Central α2-adrenoceptors and the pontine lateral parabrachial nucleus
(LPBN) are involved in the control of sodium and water intake. Bilateral injections
of moxonidine (α2-adrenergic/imidazoline receptor agonist) or
noradrenaline into the LPBN strongly increases 0.3 M NaCl intake induced by a
combined treatment of furosemide plus captopril. Injection of moxonidine into the
LPBN also increases hypertonic NaCl and water intake and reduces oxytocin secretion,
urinary sodium, and water excreted by cell-dehydrated rats, causing a positive sodium
and water balance, which suggests that moxonidine injected into the LPBN deactivates
mechanisms that restrain body fluid volume expansion. Pretreatment with specific
α2-adrenoceptor antagonists injected into the LPBN abolishes the
behavioral and renal effects of moxonidine or noradrenaline injected into the same
area, suggesting that these effects depend on activation of LPBN
α2-adrenoceptors. In fluid-depleted rats, the palatability of sodium is
reduced by ingestion of hypertonic NaCl, limiting intake. However, in rats treated
with moxonidine injected into the LPBN, the NaCl palatability remains high, even
after ingestion of significant amounts of 0.3 M NaCl. The changes in behavioral and
renal responses produced by activation of α2-adrenoceptors in the LPBN are
probably a consequence of reduction of oxytocin secretion and blockade of inhibitory
signals that affect sodium palatability. In this review, a model is proposed to show
how activation of α2-adrenoceptors in the LPBN may affect palatability
and, consequently, ingestion of sodium as well as renal sodium excretion.
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Affiliation(s)
- C A F Andrade
- Departamento de Fisiologia e Patologia, Faculdade de Odontologia, Universidade Estadual Paulista, AraraquaraSP, Brasil, Departamento de Fisiologia e Patologia, Faculdade de Odontologia, Universidade Estadual Paulista, Araraquara, SP, Brasil
| | - G M F Andrade-Franzé
- Departamento de Fisiologia e Patologia, Faculdade de Odontologia, Universidade Estadual Paulista, AraraquaraSP, Brasil, Departamento de Fisiologia e Patologia, Faculdade de Odontologia, Universidade Estadual Paulista, Araraquara, SP, Brasil
| | - P M De Paula
- Departamento de Fisiologia e Patologia, Faculdade de Odontologia, Universidade Estadual Paulista, AraraquaraSP, Brasil, Departamento de Fisiologia e Patologia, Faculdade de Odontologia, Universidade Estadual Paulista, Araraquara, SP, Brasil
| | - L A De Luca
- Departamento de Fisiologia e Patologia, Faculdade de Odontologia, Universidade Estadual Paulista, AraraquaraSP, Brasil, Departamento de Fisiologia e Patologia, Faculdade de Odontologia, Universidade Estadual Paulista, Araraquara, SP, Brasil
| | - J V Menani
- Departamento de Fisiologia e Patologia, Faculdade de Odontologia, Universidade Estadual Paulista, AraraquaraSP, Brasil, Departamento de Fisiologia e Patologia, Faculdade de Odontologia, Universidade Estadual Paulista, Araraquara, SP, Brasil
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Menani JV, De Luca LA, Johnson AK. Role of the lateral parabrachial nucleus in the control of sodium appetite. Am J Physiol Regul Integr Comp Physiol 2014; 306:R201-10. [PMID: 24401989 DOI: 10.1152/ajpregu.00251.2012] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In states of sodium deficiency many animals seek and consume salty solutions to restore body fluid homeostasis. These behaviors reflect the presence of sodium appetite that is a manifestation of a pattern of central nervous system (CNS) activity with facilitatory and inhibitory components that are affected by several neurohumoral factors. The primary focus of this review is on one structure in this central system, the lateral parabrachial nucleus (LPBN). However, before turning to a more detailed discussion of the LPBN, a brief overview of body fluid balance-related body-to-brain signaling and the identification of the primary CNS structures and humoral factors involved in the control of sodium appetite is necessary. Angiotensin II, mineralocorticoids, and extracellular osmotic changes act on forebrain areas to facilitate sodium appetite and thirst. In the hindbrain, the LPBN functions as a key integrative node with an ascending output that exerts inhibitory influences on forebrain regions. A nonspecific or general deactivation of LPBN-associated inhibition by GABA or opioid agonists produces NaCl intake in euhydrated rats without any other treatment. Selective LPBN manipulation of other neurotransmitter systems [e.g., serotonin, cholecystokinin (CCK), corticotrophin-releasing factor (CRF), glutamate, ATP, or norepinephrine] greatly enhances NaCl intake when accompanied by additional treatments that induce either thirst or sodium appetite. The LPBN interacts with key forebrain areas that include the subfornical organ and central amygdala to determine sodium intake. To summarize, a model of LPBN inhibitory actions on forebrain facilitatory components for the control of sodium appetite is presented in this review.
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Affiliation(s)
- Jose V Menani
- Department of Physiology and Pathology, School of Dentistry, Universidade Estadual Paulista, Araraquara, São Paulo, Brazil; and Departments of Psychology, Pharmacology and Health, and Human Physiology and the Cardiovascular Center, University of Iowa, Iowa City, Iowa
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Kimura EH, De Oliveira LB, Menani JV, Callera JC. Baclofen into the lateral parabrachial nucleus induces hypertonic sodium chloride intake during cell dehydration. Behav Brain Funct 2013; 9:17. [PMID: 23642235 PMCID: PMC3679877 DOI: 10.1186/1744-9081-9-17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 04/23/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Activation of GABA(B) receptors with baclofen into the lateral parabrachial nucleus (LPBN) induces ingestion of water and 0.3 M NaCl in fluid replete rats. However, up to now, no study has investigated the effects of baclofen injected alone or combined with GABA(B) receptor antagonist into the LPBN on water and 0.3 M NaCl intake in rats with increased plasma osmolarity (rats treated with an intragastric load of 2 M NaCl). Male Wistar rats with stainless steel cannulas implanted bilaterally into the LPBN were used. RESULTS In fluid replete rats, baclofen (0.5 nmol/0.2 μl), bilaterally injected into the LPBN, induced ingestion of 0.3 M NaCl (14.3 ± 4.1 vs. saline: 0.2 ± 0.2 ml/210 min) and water (7.1 ± 2.9 vs. saline: 0.6 ± 0.5 ml/210 min). In cell-dehydrated rats, bilateral injections of baclofen (0.5 and 1.0 nmol/0.2 μl) into the LPBN induced an increase of 0.3 M NaCl intake (15.6 ± 5.7 and 21.5 ± 3.5 ml/210 min, respectively, vs. saline: 1.7 ± 0.8 ml/210 min) and an early inhibition of water intake (3.5 ± 1.4 and 6.7 ± 2.1 ml/150 min, respectively, vs. saline: 9.2 ± 1.4 ml/150 min). The pretreatment of the LPBN with 2-hydroxysaclofen (GABA(B) antagonist, 5 nmol/0.2 μl) potentiated the effect of baclofen on 0.3 M NaCl intake in the first 90 min of test and did not modify the inhibition of water intake induced by baclofen in cell-dehydrated rats. Baclofen injected into the LPBN did not affect blood pressure and heart rate. CONCLUSIONS Thus, injection of baclofen into the LPBN in cell-dehydrated rats induced ingestion of 0.3 M NaCl and inhibition of water intake, suggesting that even in a hyperosmotic situation, the blockade of LPBN inhibitory mechanisms with baclofen is enough to drive rats to drink hypertonic NaCl, an effect independent of changes in blood pressure.
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Affiliation(s)
- Everton H Kimura
- Department of Basic Sciences, School of Dentistry, UNESP - Univ. Estadual Paulista, Rodovia Marechal Rondom, km 527, Araçatuba, São Paulo 16018-805, Brazil
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Asnar DS, Roncari CF, De Luca LA, de Paula PM, Colombari DS, Menani JV. Involvement of central cholinergic mechanisms on sodium intake induced by gabaergic activation of the lateral parabrachial nucleus. Neurosci Lett 2013; 534:188-92. [DOI: 10.1016/j.neulet.2012.11.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 11/16/2012] [Accepted: 11/17/2012] [Indexed: 11/17/2022]
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19
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Hoeller AA, dos Santos TS, Bruxel RR, Dallazen AR, do Amaral Silva HT, André ES, Marino-Neto J. Serotonergic control of ingestive and post-ingestive behaviors in pigeons (Columba livia): The role of 5-HT1A receptor-mediated central mechanisms. Behav Brain Res 2013; 236:118-130. [DOI: 10.1016/j.bbr.2012.08.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 07/26/2012] [Accepted: 08/16/2012] [Indexed: 12/11/2022]
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20
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Andrade C, Margatho L, Andrade-Franzé G, De Luca L, Antunes-Rodrigues J, Menani J. Moxonidine into the lateral parabrachial nucleus reduces renal and hormonal responses to cell dehydration. Neuroscience 2012; 208:69-78. [DOI: 10.1016/j.neuroscience.2012.02.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 02/07/2012] [Accepted: 02/07/2012] [Indexed: 11/27/2022]
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21
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Da Silva CZC, Menani JV, Callera JC. AT1 receptor blockade in the lateral parabrachial nucleus reduces the effects of muscimol on sodium intake. Brain Res 2011; 1403:28-36. [DOI: 10.1016/j.brainres.2011.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 05/30/2011] [Accepted: 06/02/2011] [Indexed: 11/29/2022]
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22
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Yang W, Mao C, Xia F, Zheng J, Wang A, Zhu L, He R, Xu Z. Changed salt appetite and central angiotensin II-induced cellular activation in rat offspring following hypoxia during fetal stages. Peptides 2010; 31:1177-83. [PMID: 20307607 PMCID: PMC3581437 DOI: 10.1016/j.peptides.2010.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2010] [Revised: 03/09/2010] [Accepted: 03/09/2010] [Indexed: 01/13/2023]
Abstract
Hypoxia in pregnancy may induce fetal growth restriction and cause functional abnormalities during development. The present study determined the long-term influence of hypoxia in fetal life on dipsogenic behavior linked to central angiotensin (Ang) network in the offspring rats. Fetal blood pO(2) and body weight were decreased by hypoxia during pregnancy, followed by a postnatal "catch-up" growth. Subcutaneous hypertonic saline or intracerebroventricular Ang II significantly increased salt intake in the offspring prenatally exposed to hypoxia, while water intake was the same between the two groups. Ang II-induced c-fos expression was detected in the paraventricular nuclei, median preoptic nuclei, supraoptic nuclei, and subfornical organ in the brain, in association with reduced forebrain AT(2) receptor protein abundance in the offspring prenatally exposed to hypoxia. Levels of central AT(1) receptor protein were not changed between the two groups. Hypoxia during pregnancy could be linked to developmental problems related to behavioral dysfunctions in body fluid regulations in later life, in association with the change in central angiotensin II-mediated neural activation and expression of the Ang II receptor in the brain.
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Affiliation(s)
- Weili Yang
- First Hospital of Soochow University & Perinatal Biology Center, Soochow University, Suzhou 215123, China
| | - Caiping Mao
- First Hospital of Soochow University & Perinatal Biology Center, Soochow University, Suzhou 215123, China
| | - Fei Xia
- First Hospital of Soochow University & Perinatal Biology Center, Soochow University, Suzhou 215123, China
| | - Jianli Zheng
- First Hospital of Soochow University & Perinatal Biology Center, Soochow University, Suzhou 215123, China
| | - Aiqing Wang
- First Hospital of Soochow University & Perinatal Biology Center, Soochow University, Suzhou 215123, China
| | - Liyan Zhu
- First Hospital of Soochow University & Perinatal Biology Center, Soochow University, Suzhou 215123, China
| | - Rui He
- First Hospital of Soochow University & Perinatal Biology Center, Soochow University, Suzhou 215123, China
| | - Zhice Xu
- First Hospital of Soochow University & Perinatal Biology Center, Soochow University, Suzhou 215123, China
- Center for Perinatal Biology, Loma Linda University, CA 92350, USA
- Corresponding author at: First Hospital of Soochow University & Perinatal Biology Center, Soochow University, Suzhou, China. Tel.: +86 512 65880125; fax: +86 512 65880103. (Z. Xu)
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Davern PJ, McKinley MJ. Forebrain regions affected by lateral parabrachial nucleus serotonergic mechanisms that influence sodium appetite. Brain Res 2010; 1339:41-8. [PMID: 20399756 DOI: 10.1016/j.brainres.2010.04.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 03/24/2010] [Accepted: 04/09/2010] [Indexed: 11/29/2022]
Abstract
Blockade of serotonergic receptors in the lateral parabrachial nucleus (LPBN), via bilateral injections of nonselective 5-hydroxytryptamine (5-HT)(1/2)-receptor antagonist, methysergide causes a robust sodium appetite. Our aim was to elucidate which brain regions are activated when serotonergic pathways to the LPBN are blocked and combined with subcutaneous injection of isoproterenol causing a salt appetite. In the experimental group, conscious rats were administered methysergide (4 microg/0.2 microl) injected bilaterally into the LPBN. Control groups included rats administered with injections of vehicle bilaterally into the LPBN, rats administered methysergide into injection sites outside the LPB region, and rats that did not undergo surgery. Each group was treated with a subcutaneous injection of isoproterenol (30 microg/kg), a beta-adrenergic agonist, and NaCl and water intakes were measured over 2h. Bilateral injections of methysergide into the LPBN followed by subcutaneous isoproterenol induced a strong intake of 0.3M NaCl (p<0.01) compared with all controls. Greater numbers of c-Fos-positive stained nuclei were observed in all brain regions assessed. The extended amygdala is rich in AT(1) receptors and ablation of these regions has been shown to reduce sodium appetite; therefore, neurons in these sites, and to a lesser extent the lamina terminalis, are likely primary targets of an inhibitory mechanism arising from the LPBN that acts to modulate sodium appetite.
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Affiliation(s)
- Pamela J Davern
- Howard Florey Institute, University of Melbourne, Parkville, Victoria, Australia.
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24
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Horn CC, De Jonghe BC, Matyas K, Norgren R. Chemotherapy-induced kaolin intake is increased by lesion of the lateral parabrachial nucleus of the rat. Am J Physiol Regul Integr Comp Physiol 2009; 297:R1375-82. [PMID: 19710391 DOI: 10.1152/ajpregu.00284.2009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Anticancer agents, such as cisplatin, stimulate nausea, vomiting, and behaviors indicative of malaise. Rats and mice do not possess a vomiting response, and, therefore, in these species, the ingestion of kaolin clay (a pica response) has been used as an index of malaise. In the rat, cisplatin-induced kaolin intake is inhibited by antiemetic treatments. In addition, cisplatin activates vagal afferent fibers in the gut, and kaolin intake induced by cisplatin is largely dependent on an intact vagus. Nevertheless, little is known about the brain pathways controlling pica. We investigated the role of the lateral parabrachial nucleus (lPBN), a major visceral afferent link between the hindbrain and forebrain, in cisplatin-induced c-Fos expression and pica. Injection of cisplatin (6 mg/kg ip) produced c-Fos expression in the ventrolateral (external) lPBN, a region receiving viscerosensory input. In rats with bilateral ibotenic acid lPBN lesions, cisplatin treatment substantially increased kaolin intake compared with controls ( approximately 30 g vs. approximately 5 g, respectively, over 24 h). Food intake was reduced by cisplatin treatment and by apomorphine, an emetic agent that acts centrally. Unlike cisplatin, however, apomorphine stimulated kaolin intake to a similar degree in both the lesioned and control rats, suggesting that lPBN damage neither produces nonspecific effects nor enhances malaise in general. These data suggest that lPBN-lesioned animals not only demonstrate pica after cisplatin treatment, but, in fact, show an exaggerated response that is greatly in excess of any treatment known to produce kaolin intake in rats.
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Affiliation(s)
- Charles C Horn
- Monell Chemical Senses Center, Philadelphia, Pennsylvania 15213, USA.
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25
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Sodium intake by hyperosmotic rats treated with a GABAA receptor agonist into the lateral parabrachial nucleus. Brain Res 2008; 1190:86-93. [DOI: 10.1016/j.brainres.2007.11.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Revised: 10/27/2007] [Accepted: 11/04/2007] [Indexed: 11/23/2022]
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26
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Serotonergic receptor blockade in the lateral parabrachial nucleus: Different effects on hypertonic and isotonic NaCl intake. Brain Res 2008; 1187:137-45. [DOI: 10.1016/j.brainres.2007.10.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 10/03/2007] [Accepted: 10/06/2007] [Indexed: 11/22/2022]
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27
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de Oliveira LB, Callera JC, De Luca LA, Colombari DSA, Menani JV. GABAergic mechanisms of the lateral parabrachial nucleus on sodium appetite. Brain Res Bull 2007; 73:238-47. [PMID: 17562389 DOI: 10.1016/j.brainresbull.2007.03.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Revised: 02/25/2007] [Accepted: 03/14/2007] [Indexed: 11/26/2022]
Abstract
GABAergic activation in the lateral parabrachial nucleus (LPBN) induces sodium and water intake in satiated and normovolemic rats. In the present study we investigated the effects of GABAA receptor activation in the LPBN on 0.3M NaCl, water, 2% sucrose and food intake in rats submitted to sodium depletion (treatment with the diuretic furosemide subcutaneously+sodium deficient food for 24h), 24h food deprivation or 24 h water deprivation. Male Holtzman rats with bilateral stainless steel cannulas implanted into the LPBN were used. In sodium depleted rats, muscimol (GABAA receptor agonist, 0.5 nmol/0.2 microl), bilaterally injected into the LPBN, produced an inconsistent increase of water intake and two opposite effects on 0.3M NaCl intake: an early inhibition (4.3+/-2.7 versus saline: 14.4+/-1.0 ml/15 min) and a late facilitation (37.6+/-2.7 versus saline: 21.1+/-0.9 ml/180 min). The pretreatment of the LPBN with bicuculline (GABAA receptor antagonist, 1.6 nmol) abolished these effects of muscimol. Muscimol into the LPBN also reduced food deprivation-induced food intake in the first 30 min of test (1.7+/-0.6g versus saline: 4.1+/-0.6g), without changing water deprivation-induced water intake or 2% sucrose intake in sodium depleted rats. Therefore, although GABAA receptors in the LPBN are not tonically involved in the control of sodium depletion-induced sodium intake, GABAA receptor activation in the LPBN produces an early inhibition and a late facilitation of sodium depletion-induced sodium intake. GABAA activation in the LPBN also inhibits food intake, while it consistently increases only sodium intake and not water, food or sucrose intake.
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Affiliation(s)
- Lisandra B de Oliveira
- Department of Physiology and Pathology, School of Dentistry, UNESP, Rua Humaitá 1680, 14801-903 Araraquara, SP, Brazil
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28
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Andrade CAF, De Luca LA, Colombari DSA, Menani JV. Alpha2-adrenergic activation in the lateral parabrachial nucleus induces NaCl intake under conditions of systemic hyperosmolarity. Neuroscience 2006; 142:21-8. [PMID: 16890365 DOI: 10.1016/j.neuroscience.2006.04.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Revised: 04/10/2006] [Accepted: 04/13/2006] [Indexed: 10/24/2022]
Abstract
The inhibition of sodium intake by increased plasma osmolarity may depend on inhibitory mechanisms present in the lateral parabrachial nucleus. Activation of alpha(2)-adrenergic receptors in the lateral parabrachial nucleus is suggested to deactivate inhibitory mechanisms present in this area increasing fluid depletion-induced 0.3 M NaCl intake. Considering the possibility that lateral parabrachial nucleus inhibitory mechanisms are activated and restrain sodium intake in animals with increased plasma osmolarity, in the present study we investigated the effects on water and 0.3 M NaCl intake produced by the activation of alpha(2)-adrenergic receptors in the lateral parabrachial nucleus in rats with increased plasma osmolarity. Male Holtzman rats with stainless steel cannulas implanted bilaterally into the lateral parabrachial nucleus were used. One hour after intragastric 2 M NaCl load (2 ml), bilateral injections of moxonidine (alpha(2)-adrenergic/imidazoline receptor agonist, 0.5 nmol/0.2 microl, n=10) into the lateral parabrachial nucleus induced a strong ingestion of 0.3 M NaCl intake (19.1+/-5.5 ml/2 h vs. vehicle: 1.8+/-0.6 ml/2 h), without changing water intake (15.8+/-3.0 ml/2 h vs. vehicle: 9.3+/-2.0 ml/2 h). However, moxonidine into the lateral parabrachial nucleus in satiated rats not treated with 2 M NaCl produced no change on 0.3 M NaCl intake. The pre-treatment with RX 821002 (alpha(2)-adrenergic receptor antagonist, 20 nmol/0.2 microl) into the lateral parabrachial nucleus almost abolished the effects of moxonidine on 0.3 M NaCl intake (4.7+/-3.4 ml/2 h). The present results suggest that alpha(2)-adrenergic receptor activation in the lateral parabrachial nucleus blocks inhibitory mechanisms, thereby allowing ingestion of hypertonic NaCl under conditions of extracellular hyperosmolarity. We suggest that during cell dehydration, circuits subserving sodium appetite are activated, but at the same time strongly inhibited through the lateral parabrachial nucleus.
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Affiliation(s)
- C A F Andrade
- Department of Physiology and Pathology, School of Dentistry, Universidade Estadual Paulista, Rua Humaitá 1680, Araraquara, SP 14801-903, Brazil
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29
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Gargaglioni LH, Bícego KC, Nucci TB, Branco LGS. Serotoninergic receptors in the anteroventral preoptic region modulate the hypoxic ventilatory response. Respir Physiol Neurobiol 2005; 153:1-13. [PMID: 16310416 DOI: 10.1016/j.resp.2005.09.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2005] [Revised: 09/01/2005] [Accepted: 09/07/2005] [Indexed: 10/25/2022]
Abstract
Hypothalamus is a site of integration of the hypoxic and thermal stimuli on breathing and there is evidence that serotonin (5-HT) receptors in the anteroventral preoptic region (AVPO) mediate hypoxic hypothermia. Once 5-HT is involved in the hypoxic ventilatory response (HVR), we investigated the participation of the 5-HT receptors (5-HT1, 5-HT2 and 5-HT7) in the AVPO in the HVR. To this end, pulmonary ventilation (V(E)) of rats was measured before and after intra-AVPO microinjection of methysergide (a 5-HT1 and 5-HT2 receptor antagonist), WAY-100635 (a 5-HT1A receptor antagonist) and SB-269970 (a 5-HT7 receptor antagonist), followed by 60 min of hypoxia exposure (7% O2). Intra-AVPO microinjection of vehicles or 5-HT antagonists did not change V(E) during normoxic conditions. Exposure of rats to 7% O2 evoked typical hypoxia-induced hyperpnea after vehicle microinjection, which was not affected by methysergide. WAY-100635 and SB-269970 treatment caused an increased HVR, due to a higher tidal volume. Therefore, the current data provide the evidence that 5-HT acting on 5-HT1A and 5-HT7 receptors in the AVPO exert an inhibitory modulation on the HVR.
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Affiliation(s)
- Luciane H Gargaglioni
- Department of Animal Morphology and Physiology, State University of Sao Paulo at Jaboticabal, SP, Brazil.
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30
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Gargaglioni LH, Steiner AA, Branco LGS. Involvement of serotoninergic receptors in the anteroventral preoptic region on hypoxia-induced hypothermia. Brain Res 2005; 1044:16-24. [PMID: 15862785 DOI: 10.1016/j.brainres.2005.02.069] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2004] [Revised: 02/16/2005] [Accepted: 02/23/2005] [Indexed: 10/25/2022]
Abstract
Hypoxia causes a regulated decrease in body temperature (Tb). There is circumstantial evidence that the neurotransmitter serotonin (5-HT) in the anteroventral preoptic region (AVPO) mediates this response. However, which 5-HT receptor(s) is (are) involved in this response has not been assessed. Thus, we investigated the participation of the 5-HT receptors (5-HT1, 5-HT2, and 5-HT7) in the AVPO in hypoxic hypothermia. To this end, Tb of conscious Wistar rats was monitored by biotelemetry before and after intra-AVPO microinjection of methysergide (a 5-HT1 and 5-HT2 receptor antagonist, 0.2 and 2 microg/100 nL), WAY-100635 (a 5-HT(1A) receptor antagonist, 0.3 and 3 microg/100 nL), and SB-269970 (a 5-HT7 receptor antagonist, 0.4 and 4 micro/100 nL), followed by 60 min of hypoxia exposure (7% O2). During the experiments, the mean chamber temperature was 24.6 +/- 0.7 degrees C (mean +/- SE) and the mean room temperature was 23.5 +/- 0.8 degrees C (mean +/- SE). Intra-AVPO microinjection of vehicle or 5-HT antagonists did not change Tb during normoxic conditions. Exposure of rats to 7% of inspired oxygen evoked typical hypoxia-induced hypothermia after vehicle microinjection, which was not affected by both doses of methysergide. However, WAY-100635 and SB-269970 treatment attenuated the drop in Tb in response to hypoxia. The effect was more pronounced with the 5-HT7 antagonist since both doses (0.4 and 4 microg/0.1 microL) were capable of attenuating the hypothermic response. As to the 5-HT(1A) antagonist, the attenuation of hypoxia-induced hypothermia was only observed at the higher dose. Therefore, the present results are consistent with the notion that 5-HT acts on both 5-HT(1A) and 5-HT7 receptors in the AVPO to induce hypothermia, during hypoxia.
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Affiliation(s)
- Luciane H Gargaglioni
- Department of Animal Morphology and Physiology, State University of Sao Paulo-FCAV at Jaboticabal, SP, Brazil.
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31
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Menani JV, Barbosa SP, McKinley MJ, Wade JD, De Luca LA. Serotonergic mechanism of the lateral parabrachial nucleus and relaxin-induced sodium intake. Brain Res 2004; 1030:74-80. [PMID: 15567339 DOI: 10.1016/j.brainres.2004.09.048] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2004] [Indexed: 11/20/2022]
Abstract
It has been shown that central or peripheral injections of the peptide relaxin induces water intake, not sodium intake in rats. Important inhibitory mechanisms involving serotonin and other neurotransmitters in the control of water and NaCl intake have been demonstrated in the lateral parabrachial nucleus (LPBN). In the present study, we investigated the effects of bilateral injections of methysergide (serotonergic receptor antagonist) into the LPBN on intracerebroventricular (i.c.v.) relaxin-induced water and NaCl intake in rats. Additionally, the effect of the blockade of central angiotensin AT(1) receptors with i.c.v. losartan on relaxin-induced water and NaCl intake in rats treated with methysergide into the LPBN was also investigated. Male Holtzman rats with cannulas implanted into the lateral ventricle (LV) and bilaterally in the LPBN were used. Intracerebroventricular injections of relaxin (500 ng/1 microl) induced water intake (5.1+/-0.7 ml/120 min), but not significant 1.8% NaCl intake (0.5+/-0.4 ml/120 min). Bilateral injections of methysergide (4 microg/0.2 microl) into the LPBN strongly stimulated relaxin-induced 1.8% NaCl intake (34.5+/-10.9 ml/120 min) and slightly increased water intake (10.5+/-4.9 ml/120 min). The pretreatment with i.c.v. losartan (100 microg/1 microl) abolished the effects of i.c.v. relaxin combined with LPBN methysergide on 1.8% NaCl intake (0.5+/-0.4 ml/120 min). Losartan (100 microg/1 microl) also abolished relaxin-induced water intake in rats injected with methysergide into the LPBN (1.6+/-0.8 ml/120 min) or not (0.5+/-0.3 ml/120 min). Losartan (50 microg/1 microl) partially reduced the effects of relaxin. The results show that central relaxin interacting with central angiotensinergic mechanisms induces NaCl intake after the blockade of LPBN serotonergic mechanisms.
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Affiliation(s)
- J V Menani
- Department of Physiology and Pathology, School of Dentistry, Paulista State University, 14801-903 Araraquara, São Paulo, Brazil.
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32
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Andrade CAF, Barbosa SP, De Luca LA, Menani JV. Activation of α2-adrenergic receptors into the lateral parabrachial nucleus enhances NaCl intake in rats. Neuroscience 2004; 129:25-34. [PMID: 15489025 DOI: 10.1016/j.neuroscience.2004.07.042] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/22/2004] [Indexed: 11/24/2022]
Abstract
Water and NaCl intake is strongly inhibited by the activation of alpha(2)-adrenergic receptors with clonidine or moxonidine (alpha(2)-adrenergic/imidazoline agonists) injected peripherally or into the forebrain and by serotonin and cholecystokinin in the lateral parabrachial nucleus (LPBN). Considering that alpha(2)-adrenergic receptors exist in the LPBN and the similar origin of serotonergic and adrenergic afferent pathways to the LPBN, in this study we investigated the effects of bilateral injections of moxonidine alone or combined with RX 821002 (alpha(2)-adrenergic antagonist) into the LPBN on 1.8% NaCl and water intake induced by the treatment with s.c. furosemide (10mg/kg)+captopril (5 mg/kg). Additionally, we investigated if moxonidine into the LPBN would modify furosemide+captopril-induced c-fos expression in the forebrain. Male Holtzman rats with cannulas implanted bilaterally in the LPBN were used. Contrary to forebrain injections, bilateral LPBN injections of moxonidine (0.1, 0.5 and 1 nmol/0.2 microl) strongly increased furosemide+captopril-induced 1.8% NaCl intake (16.6+/-2.7, 44.5+/-3.2 and 44.5+/-4.3 ml/2 h, respectively, vs. vehicle: 6.9+/-1.5 ml/2 h). Only the high dose of moxonidine increased water intake (23.3+/-3.8 ml/2 h, vs. vehicle: 12.1+/-2.6 ml/2 h). Prior injections of RX 821002 (10 and 20 nmol/0.2 microl) abolished the effect of moxonidine (0.5 nmol) on 1.8% NaCl intake. Moxonidine into the LPBN did not modify furosemide+captopril-induced c-fos expression in forebrain areas related to the control of fluid-electrolyte balance. The results show that the activation of LPBN alpha(2)-adrenergic receptors enhances furosemide+captopril-induced 1.8% NaCl and water intake. This enhancement was not related to prior alteration in the activity of forebrain areas as suggested by c-fos expression. Previous and present results indicate opposite roles for alpha(2)-adrenergic receptors in the control of sodium and water intake according to their distribution in the rat brain.
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Affiliation(s)
- C A F Andrade
- Department of Physiology and Pathology, School of Dentistry, Paulista State University (UNESP), Rua Humaitá, 1680, 14801-903 Araraquara, São Paulo, Brazil
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