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Ventromedial medullary pathway mediating cardiac responses evoked from periaqueductal gray. Auton Neurosci 2020; 228:102716. [PMID: 32882606 DOI: 10.1016/j.autneu.2020.102716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 07/23/2020] [Accepted: 08/07/2020] [Indexed: 11/20/2022]
Abstract
Periaqueductal gray (PAG) is a midbrain region that projects to areas controlling behavioral and autonomic outputs and is involved in the behavioral and physiological components of defense reactions. Since Raphe Pallidus (RPa) is a medial medullary region comprising sympathetic premotor neurons governing heart function, it is worth considering the PAG-RPa path. We assessed: i) whether PAG projects to RPa; ii) the amplitude of cardiac responses evoked from PAG; iii) whether cardiovascular responses evoked from PAG rely on RPa. Experiments conducted in Wistar rats (±300 g) were approved by Ethics Committee CEUA-UFG (092/18). Firstly, (n = 3), monosynaptic retrograde tracer Retrobeads was injected into RPa; PAG slices were analyzed. Other two groups (n = 6 each) were anesthetized with urethane (1.4 g/kg) and chloralose (120 mg/kg) and underwent craniotomy, tracheostomy, catheterization of femoral artery and vein and of cardiac left ventricle. In one group, we injected the GABAA receptor antagonist, bicuculline methiodide (BMI - 40 pmol/100 nL) into lateral/dorsolateral PAG. Another group was injected (100 nL) with the GABAA receptor agonist muscimol (20 mM) into RPa, 20 min before BMI into PAG. The results were: i) retrogradely labelled neurons were found in PAG; ii) PAG activation by BMI caused positive chronotropism and inotropism, which were accompanied by afterload increases; iii) RPa inhibition with Muscimol reduced heart rate, arterial and ventricular pressures; iv) the subsequent PAG activation still increased arterial pressure, cardiac chronotropy and inotropy, but these responses were significantly attenuated. In conclusion, PAG activation increases cardiac chronotropy and inotropy, and these responses seem to rely on a direct pathway reaching ventromedial medullary RPa neurons.
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Kiss DS, Toth I, Jocsak G, Barany Z, Bartha T, Frenyo LV, Horvath TL, Zsarnovszky A. Functional Aspects of Hypothalamic Asymmetry. Brain Sci 2020; 10:brainsci10060389. [PMID: 32575391 PMCID: PMC7349050 DOI: 10.3390/brainsci10060389] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/08/2020] [Accepted: 06/16/2020] [Indexed: 01/12/2023] Open
Abstract
Anatomically, the brain is a symmetric structure. However, growing evidence suggests that certain higher brain functions are regulated by only one of the otherwise duplicated (and symmetric) brain halves. Hemispheric specialization correlates with phylogeny supporting intellectual evolution by providing an ergonomic way of brain processing. The more complex the task, the higher are the benefits of the functional lateralization (all higher functions show some degree of lateralized task sharing). Functional asymmetry has been broadly studied in several brain areas with mirrored halves, such as the telencephalon, hippocampus, etc. Despite its paired structure, the hypothalamus has been generally considered as a functionally unpaired unit, nonetheless the regulation of a vast number of strongly interrelated homeostatic processes are attributed to this relatively small brain region. In this review, we collected all available knowledge supporting the hypothesis that a functional lateralization of the hypothalamus exists. We collected and discussed findings from previous studies that have demonstrated lateralized hypothalamic control of the reproductive functions and energy expenditure. Also, sporadic data claims the existence of a partial functional asymmetry in the regulation of the circadian rhythm, body temperature and circulatory functions. This hitherto neglected data highlights the likely high-level ergonomics provided by such functional asymmetry.
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Affiliation(s)
- David Sandor Kiss
- Department of Physiology and Biochemistry, University of Veterinary Medicine, 1078 Budapest, Hungary; (I.T.); (G.J.); (Z.B.); (T.B.); (L.V.F.)
- Correspondence: ; Tel.: +36-1478-4247 or +36-1478-8406
| | - Istvan Toth
- Department of Physiology and Biochemistry, University of Veterinary Medicine, 1078 Budapest, Hungary; (I.T.); (G.J.); (Z.B.); (T.B.); (L.V.F.)
| | - Gergely Jocsak
- Department of Physiology and Biochemistry, University of Veterinary Medicine, 1078 Budapest, Hungary; (I.T.); (G.J.); (Z.B.); (T.B.); (L.V.F.)
| | - Zoltan Barany
- Department of Physiology and Biochemistry, University of Veterinary Medicine, 1078 Budapest, Hungary; (I.T.); (G.J.); (Z.B.); (T.B.); (L.V.F.)
| | - Tibor Bartha
- Department of Physiology and Biochemistry, University of Veterinary Medicine, 1078 Budapest, Hungary; (I.T.); (G.J.); (Z.B.); (T.B.); (L.V.F.)
| | - Laszlo V. Frenyo
- Department of Physiology and Biochemistry, University of Veterinary Medicine, 1078 Budapest, Hungary; (I.T.); (G.J.); (Z.B.); (T.B.); (L.V.F.)
| | - Tamas L. Horvath
- Department of Animal Physiology and Animal Health, Szent Istvan University, Faculty of Agricultural and Environmental Sciences, 2100 Gödöllő, Hungary; (T.L.H.); (A.Z.)
- Division of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Attila Zsarnovszky
- Department of Animal Physiology and Animal Health, Szent Istvan University, Faculty of Agricultural and Environmental Sciences, 2100 Gödöllő, Hungary; (T.L.H.); (A.Z.)
- Division of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
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Periaqueductal gray and emotions: the complexity of the problem and the light at the end of the tunnel, the magnetic resonance imaging. Endocr Regul 2018; 52:222-238. [DOI: 10.2478/enr-2018-0027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Abstract
The periaqueductal gray (PAG) is less referred in relationship with emotions than other parts of the brain (e.g. cortex, thalamus, amygdala), most probably because of the difficulty to reach and manipulate this small and deeply lying structure. After defining how to evaluate emotions, we have reviewed the literature and summarized data of the PAG contribution to the feeling of emotions focusing on the behavioral and neurochemical considerations. In humans, emotions can be characterized by three main domains: the physiological changes, the communicative expressions, and the subjective experiences. In animals, the physiological changes can mainly be studied. Indeed, early studies have considered the PAG as an important center of the emotions-related autonomic and motoric processes. However, in vivo imaging have changed our view by highlighting the PAG as a significant player in emotions-related cognitive processes. The PAG lies on the crossroad of networks important in the regulation of emotions and therefore it should not be neglected. In vivo imaging represents a good tool for studying this structure in living organism and may reveal new information about its role beyond its importance in the neurovegetative regulation.
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Xavier CH, Mendonça MM, Marins FR, da Silva ES, Ianzer D, Colugnati DB, Pedrino GR, Fontes MAP. Stating asymmetry in neural pathways: methodological trends in autonomic neuroscience. Int J Neurosci 2018; 128:1078-1085. [DOI: 10.1080/00207454.2018.1473396] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Carlos Henrique Xavier
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Michelle Mendanha Mendonça
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Fernanda Ribeiro Marins
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Elder Sales da Silva
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Danielle Ianzer
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Diego Basile Colugnati
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Gustavo Rodrigues Pedrino
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Marco Antonio Peliky Fontes
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Asymmetric sympathetic output: The dorsomedial hypothalamus as a potential link between emotional stress and cardiac arrhythmias. Auton Neurosci 2017; 207:22-27. [DOI: 10.1016/j.autneu.2017.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 01/03/2017] [Accepted: 01/10/2017] [Indexed: 12/20/2022]
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Combining Epinephrine and Esmolol Attenuates Excessive Autophagy and Mitophagy in Rat Cardiomyocytes After Cardiac Arrest. J Cardiovasc Pharmacol 2016. [PMID: 26222992 DOI: 10.1097/fjc.0000000000000295] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Recent experimental and clinical studies have indicated that the β-adrenergic effect of epinephrine significantly increases the severity of postresuscitation myocardial dysfunction. The aim of this study was to investigate whether the short-acting β1-selective adrenergic blocking agent, esmolol, would impact postresuscitation autophagy and mitophagy in cardiomyocytes in a rat cardiac arrest (CA) model. METHODS CA was induced in Sprague Dawley rats by epicardial ventricular fibrillation for 5 minutes. After successful resuscitation, the surviving rats were randomly divided into 2 groups that received femoral venous injections of epinephrine combined with either esmolol (EE group) or epinephrine (E group). Arterial blood samples were obtained at times 0, 30, and 180 minutes after return of spontaneous circulation. Surviving rats were euthanatized at 12 or 24 hours after return of spontaneous circulation, and the hearts were removed for histochemical analysis, electron microscopy, Western blotting, and TUNEL experiment. RESULTS Relative to the E group, the EE group had reduced N-Methyl-D-Aspartate receptors expression and reduced arterial lactate levels (P < 0.05), suggesting that epinephrine/esmolol can attenuate postresuscitation antioxidation and apoptosis. This protective effect also correlated with a reduction of excessive autophagy and mitophagy in the cardiomyocytes, as evidenced by a reduction in Beclin-1 and Parkin expression (P < 0.05). CONCLUSIONS Esmolol significantly alleviates postresuscitational autophagy, including mitophagy, and cardiomyocyte apoptosis in a rat CA model.
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Silva FC, Paiva FA, Müller-Ribeiro FC, Caldeira HMA, Fontes MAP, de Menezes RCA, Casali KR, Fortes GH, Tobaldini E, Solbiati M, Montano N, Dias Da Silva VJ, Chianca DA. Chronic Treatment with Ivabradine Does Not Affect Cardiovascular Autonomic Control in Rats. Front Physiol 2016; 7:305. [PMID: 27507948 PMCID: PMC4960883 DOI: 10.3389/fphys.2016.00305] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/06/2016] [Indexed: 12/05/2022] Open
Abstract
A low resting heart rate (HR) would be of great benefit in cardiovascular diseases. Ivabradine—a novel selective inhibitor of hyperpolarization-activated cyclic nucleotide gated (HCN) channels- has emerged as a promising HR lowering drug. Its effects on the autonomic HR control are little known. This study assessed the effects of chronic treatment with ivabradine on the modulatory, reflex and tonic cardiovascular autonomic control and on the renal sympathetic nerve activity (RSNA). Male Wistar rats were divided in 2 groups, receiving intraperitoneal injections of vehicle (VEH) or ivabradine (IVA) during 7 or 8 consecutive days. Rats were submitted to vessels cannulation to perform arterial blood pressure (AP) and HR recordings in freely moving rats. Time series of resting pulse interval and systolic AP were used to measure cardiovascular variability parameters. We also assessed the baroreflex, chemoreflex and the Bezold-Jarish reflex sensitivities. To better evaluate the effects of ivabradine on the autonomic control of the heart, we performed sympathetic and vagal autonomic blockade. As expected, ivabradine-treated rats showed a lower resting (VEH: 362 ± 16 bpm vs. IVA: 260 ± 14 bpm, p = 0.0005) and intrinsic HR (VEH: 369 ± 9 bpm vs. IVA: 326 ± 11 bpm, p = 0.0146). However, the chronic treatment with ivabradine did not change normalized HR spectral parameters LF (nu) (VEH: 24.2 ± 4.6 vs. IVA: 29.8 ± 6.4; p > 0.05); HF (nu) (VEH: 75.1 ± 3.7 vs. IVA: 69.2 ± 5.8; p > 0.05), any cardiovascular reflexes, neither the tonic autonomic control of the HR (tonic sympathovagal index; VEH: 0.91± 0.02 vs. IVA: 0.88 ± 0.03, p = 0.3494). We performed the AP, HR and RSNA recordings in urethane-anesthetized rats. The chronic treatment with ivabradine reduced the resting HR (VEH: 364 ± 12 bpm vs. IVA: 207 ± 11 bpm, p < 0.0001), without affecting RSNA (VEH: 117 ± 16 vs. IVA: 120 ± 9 spikes/s, p = 0.9100) and mean arterial pressure (VEH: 70 ± 4 vs. IVA: 77 ± 6 mmHg, p = 0.3293). Our results suggest that, in health rats, the long-term treatment with ivabradine directly reduces the HR without changing the RSNA modulation and the reflex and tonic autonomic control of the heart.
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Affiliation(s)
- Fernanda C Silva
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro PretoOuro Preto, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro PretoOuro Preto, Brazil
| | - Franciny A Paiva
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro PretoOuro Preto, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro PretoOuro Preto, Brazil
| | - Flávia C Müller-Ribeiro
- Laboratory of Hypertension, Institute of Biological Sciences, Department of Physiology and Biophysics, Federal University of Minas Gerais Belo Horizonte, Brazil
| | - Henrique M A Caldeira
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto Ouro Preto, Brazil
| | - Marco A P Fontes
- Laboratory of Hypertension, Institute of Biological Sciences, Department of Physiology and Biophysics, Federal University of Minas Gerais Belo Horizonte, Brazil
| | - Rodrigo C A de Menezes
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro PretoOuro Preto, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro PretoOuro Preto, Brazil
| | - Karina R Casali
- Laboratory of Biomedical Engineering, Institute of Science and Technology, Federal University of São Paulo São José dos Campos, Brazil
| | | | - Eleonora Tobaldini
- Department of Clinical Sciences and Community Health, IRCCS Ca' Granda Foundation, Ospedale Maggiore Policlinico, University of Milan Milan, Italy
| | - Monica Solbiati
- Department of Clinical Sciences and Community Health, IRCCS Ca' Granda Foundation, Ospedale Maggiore Policlinico, University of Milan Milan, Italy
| | - Nicola Montano
- Department of Clinical Sciences and Community Health, IRCCS Ca' Granda Foundation, Ospedale Maggiore Policlinico, University of Milan Milan, Italy
| | - Valdo J Dias Da Silva
- Department of Physiology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro Uberaba, Brazil
| | - Deoclécio A Chianca
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro PretoOuro Preto, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro PretoOuro Preto, Brazil
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