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Fortaleza EAT, Busnardo C, Fassini A, Belém-Filho IJA, Almeida-Pereira G, Antunes-Rodrigues J, Morgan Aguiar Corrêa F. Mechanisms involved in the cardiovascular effects caused by acute osmotic stimulation in conscious rats. Stress 2020; 23:221-232. [PMID: 31451018 DOI: 10.1080/10253890.2019.1660771] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Both the autonomic nervous system and the neuroendocrine system are activated by osmotic stimulation (OS) evoking cardiovascular effects. The current study investigated the mechanisms involved in the cardiovascular responses evoked by an acute osmotic stimulus with intraperitoneal (i.p.) injection of either isotonic (0.15 M NaCl) or hypertonic saline (0.6 M NaCl) in conscious rats. Hypertonic saline increased mean arterial pressure (MAP) and heart rate (HR) for 30 min, as well as plasma osmolality and sodium content. Urinary sodium and urinary volume were also increased. Pretreatment with the ganglion blocker pentolinium (i.v.) did not affect the pressor response, but significantly decreased the tachycardic response caused by OS. Pretreatment with the V1-vasopressin receptor antagonist dTyr(CH2)5(Me)AVP (i.v.) reduced the pressor response, without affecting the tachycardic response evoked by the hypertonic OS. Neither the pressor nor the tachycardic response to OS was affected by pretreatment with either the oxytocin receptor antagonist atosiban or the α1-antagonist prazosin. Pretreatment with the β1-antagonist atenolol had no effect on the pressor response, but markedly decreased the tachycardic response evoked by OS. Results indicate that i.p. hypertonic OS-evoked pressor response is mediated by the release of vasopressin, with a minor influence of the vascular sympathetic input.LAY SUMMARYIncreased plasma osmolality, such as that observed during dehydration or salt intake, is a potent stimulus yielding to marked cardiovascular and neuroendocrine responses. The intraperitoneal (i.p.) injection of hypertonic saline solution is a commonly used animal model to cause a sustained increase in plasma osmolality, leading to a cardiovascular response characterized by sustained blood pressure and heart increases, whose systemic mechanisms were presently studied. Our findings indicate that the pressor response to the i.p. osmotic stimulus (OS) is mediated mainly by the release of vasopressin into the blood circulation with a minor or even the noninvolvement of the vascular sympathetic nervous system, whereas activation of the sympathetic-cardiac system mediates the tachycardic response to OS.
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Affiliation(s)
| | - Cristiane Busnardo
- Department of Pharmacology, School of Medicine of Ribeirão Preto, São Paulo, Brazil
| | - Aline Fassini
- Department of Pharmacology, School of Medicine of Ribeirão Preto, São Paulo, Brazil
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Sorregotti T, Cipriano AC, Cruz FC, Mascarenhas DC, Rodgers RJ, Nunes-de-Souza RL. Amygdaloid involvement in the defensive behavior of mice exposed to the open elevated plus-maze. Behav Brain Res 2017; 338:159-165. [PMID: 29080676 DOI: 10.1016/j.bbr.2017.10.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 10/06/2017] [Accepted: 10/19/2017] [Indexed: 02/06/2023]
Abstract
Previous studies have shown that the exposure to an open elevated plus maze (oEPM, an EPM with all four open arms) elicits fear/anxiety-related responses in laboratory rodents. However, very little is known about the underlying neural substrates of these defensive behaviors. Accordingly, the present study investigated the effects of chemical inactivation of the amygdala [through local injection of cobalt chloride (CoCl2: a nonspecific synaptic blocker)] on the behavior of oEPM-exposed mice. In a second experiment, the pattern of activation of the basolateral (BLA) and central (CeA) nuclei of the amygdala was assessed through quantification of Fos protein expression in mice subjected to one of several behavioral manipulations. To avoid the confound of acute handling stress, 4 independent groups of mice were habituated daily for 10days to an enclosed EPM (eEPM) and, on day 11 prior to immunohistochemistry, were either taken directly from their home cage (control) or individually exposed for 10min to a new clean holding cage (novelty), an eEPM, or the oEPM. An additional group of mice (maze-naïve) was not subjected to either the habituation or exposure phase but were simply chosen at random from their home cages to undergo an identical immunohistochemistry procedure. Results showed that amygdala inactivation produced an anxiolytic-like profile comprising reductions in time spent in the proximal portions of the open arms and total stretched attend postures (SAP) as well as increases in time spent in the distal portions of the open arms and total head-dipping. Moreover, Fos-positive labeled cells were bilaterally increased in the amygdaloid complex, particularly in the BLA, of oEPM-exposed animals compared to all other groups. These results suggest that the amygdala (in particular, its BLA nucleus) plays a key role in the modulation of defensive behaviors in oEPM-exposed mice.
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Affiliation(s)
- Tatiani Sorregotti
- Joint Graduate Program in Physiological Sciences, UFSCar/UNESP, São Carlos, SP, 13565-905, Brazil; Laboratory of Neuropsychopharmacology, School of Pharmaceutical Sciences, Univ. Estadual Paulista, UNESP, 14800-903, Araraquara, SP, Brazil
| | - Ana Cláudia Cipriano
- Joint Graduate Program in Physiological Sciences, UFSCar/UNESP, São Carlos, SP, 13565-905, Brazil; Laboratory of Neuropsychopharmacology, School of Pharmaceutical Sciences, Univ. Estadual Paulista, UNESP, 14800-903, Araraquara, SP, Brazil
| | - Fábio Cardoso Cruz
- Department of Pharmacology, Federal University of São Paulo, 04023-901, São Paulo, SP, Brazil
| | - Diego Cardozo Mascarenhas
- Joint Graduate Program in Physiological Sciences, UFSCar/UNESP, São Carlos, SP, 13565-905, Brazil; Laboratory of Neuropsychopharmacology, School of Pharmaceutical Sciences, Univ. Estadual Paulista, UNESP, 14800-903, Araraquara, SP, Brazil
| | | | - Ricardo Luiz Nunes-de-Souza
- Joint Graduate Program in Physiological Sciences, UFSCar/UNESP, São Carlos, SP, 13565-905, Brazil; Laboratory of Neuropsychopharmacology, School of Pharmaceutical Sciences, Univ. Estadual Paulista, UNESP, 14800-903, Araraquara, SP, Brazil.
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Crestani CC, Alves FH, Gomes FV, Resstel LB, Correa FM, Herman JP. Mechanisms in the bed nucleus of the stria terminalis involved in control of autonomic and neuroendocrine functions: a review. Curr Neuropharmacol 2013; 11:141-59. [PMID: 23997750 PMCID: PMC3637669 DOI: 10.2174/1570159x11311020002] [Citation(s) in RCA: 178] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/21/2012] [Accepted: 12/03/2012] [Indexed: 12/22/2022] Open
Abstract
The bed nucleus of the stria terminalis (BNST) is a heterogeneous and complex limbic forebrain structure, which plays an important role in controlling autonomic, neuroendocrine and behavioral responses. The BNST is thought to serve as a key relay connecting limbic forebrain structures to hypothalamic and brainstem regions associated with autonomic and neuroendocrine functions. Its control of physiological and behavioral activity is mediated by local action of numerous neurotransmitters. In the present review we discuss the role of the BNST in control of both autonomic and neuroendocrine function. A description of BNST control of cardiovascular and hypothalamus-pituitary-adrenal axisactivity at rest and during physiological challenges (stress and physical exercise) is presented. Moreover, evidence for modulation of hypothalamic magnocellular neurons activity is also discussed. We attempt to focus on the discussion of BNST neurochemical mechanisms. Therefore, the source and targets of neurochemical inputs to BNST subregions and their role in control of autonomic and neuroendocrine function is discussed in details.
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Affiliation(s)
- Carlos C Crestani
- Laboratory of Pharmacology, Department of Natural Active Principles and Toxicology, School of Pharmaceutical Sciences, São Paulo State University, UNESP, Araraquara, SP, 14801-902, Brazil
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