1
|
Simera M, Veternik M, Martvon L, Kotmanova Z, Cibulkova L, Poliacek I. Differential inhibition of cough by GABA A and GABA B receptor antagonists in the nucleus of the solitary tract in cats. Respir Physiol Neurobiol 2023; 315:104115. [PMID: 37460080 DOI: 10.1016/j.resp.2023.104115] [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: 05/06/2023] [Revised: 06/28/2023] [Accepted: 07/14/2023] [Indexed: 07/22/2023]
Abstract
Bicuculline and saclofen were microinjected into the rostral (rNTS) and caudal nucleus of the solitary tract (cNTS) in 17 anesthetized cats. Electromyograms (EMGs) of the diaphragm (DIA) and abdominal muscles (ABD), esophageal pressures (EP), and blood pressure were recorded and analyzed. Bilateral microinjections of 1 mM bicuculline in the rNTS significantly reduced the number of coughs (CN), amplitudes of DIA and ABD EMG, inspiratory and expiratory EP, and prolonged the duration of the cough expiratory phase (CTE) as well as the total cough cycle duration (CTtot). Bilateral microinjections of 2 mM saclofen reduced only cough expiratory efforts. Bilateral microinjection of bicuculline in the cNTS significantly reduced CN and amplitudes of ABD EMG and elongated CTE and CTtot. Bilateral microinjections of saclofen in cNTS had no significant effect on analyzed cough parameters. Our results confirm a different GABAergic inhibitory system in the rNTS and cNTS acting on mechanically induced cough in cats.
Collapse
Affiliation(s)
- Michal Simera
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin, Institute of Medical Biophysics, Mala Hora 4, 03601 Martin, Slovakia
| | - Marcel Veternik
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin, Institute of Medical Biophysics, Mala Hora 4, 03601 Martin, Slovakia.
| | - Lukas Martvon
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin, Institute of Medical Biophysics, Mala Hora 4, 03601 Martin, Slovakia
| | - Zuzana Kotmanova
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin, Institute of Medical Biophysics, Mala Hora 4, 03601 Martin, Slovakia
| | - Lucia Cibulkova
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin, Institute of Medical Biophysics, Mala Hora 4, 03601 Martin, Slovakia
| | - Ivan Poliacek
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin, Institute of Medical Biophysics, Mala Hora 4, 03601 Martin, Slovakia
| |
Collapse
|
2
|
Matsukawa K, Iwamoto GA, Mitchell JH, Mizuno M, Kim HK, Williamson JW, Smith SA. Exaggerated renal sympathetic nerve and pressor responses during spontaneously occurring motor activity in hypertensive rats. Am J Physiol Regul Integr Comp Physiol 2023; 324:R497-R512. [PMID: 36779670 DOI: 10.1152/ajpregu.00271.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Stimulation of the mesencephalic locomotor region elicits exaggerated sympathetic nerve and pressor responses in spontaneously hypertensive rats (SHR) as compared with normotensive Wistar-Kyoto rats (WKY). This suggests that central command or its influence on vasomotor centers is augmented in hypertension. The decerebrate animal model possesses an ability to evoke intermittent bouts of spontaneously occurring motor activity (SpMA) and generates cardiovascular responses associated with the SpMA. It remains unknown whether the changes in sympathetic nerve activity and hemodynamics during SpMA are altered by hypertension. To test the hypothesis that the responses in renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) during SpMA are exaggerated with hypertension, this study aimed to compare the responses in decerebrate, paralyzed SHR, WKY, and normotensive Sprague-Dawley (SD) rats. In all strains, an abrupt increase in RSNA occurred in synchronization with tibial motor discharge (an index of motor activity) and was followed by rises in MAP and heart rate. The centrally evoked increase in RSNA and MAP during SpMA was much greater (306 ± 110%) in SHR than WKY (187 ± 146%) and SD (165 ± 44%). Although resting baroreflex-mediated changes in RSNA were not different across strains, mechanically or pharmacologically induced elevations in MAP attenuated or abolished the RSNA increase during SpMA in WKY and SD but had no effect in SHR. It is likely that the exaggerated sympathetic nerve and pressor responses during SpMA in SHR are induced along a central command pathway independent of the arterial baroreflex and/or result from central command-induced inhibition of the baroreflex.
Collapse
Affiliation(s)
- Kanji Matsukawa
- Department of Applied Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Department of Integrative Physiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Gary A Iwamoto
- Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Jere H Mitchell
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Masaki Mizuno
- Department of Applied Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Han-Kyul Kim
- Department of Applied Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Jon W Williamson
- Department of Health Care Sciences, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Scott A Smith
- Department of Applied Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| |
Collapse
|
3
|
Sakazume T, Satoh Y, Ohkoshi S. Stimulation of the center of the lateral reticular nucleus suppresses the swallowing reflex in rats. Neurosci Lett 2023; 794:136998. [PMID: 36496035 DOI: 10.1016/j.neulet.2022.136998] [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: 07/14/2022] [Revised: 11/01/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022]
Abstract
Morphological studies have demonstrated that the lateral reticular nucleus (LRt) receives fibers projected from sites that are related to control of the swallowing reflex. Although the LRt may therefore be related to control of the swallowing reflex, the functional role of the LRt in the swallowing reflex remains unknown. The present study examined whether the swallowing reflex is modulated by stimulation of the LRt. These experiments were performed on rats anesthetized by urethane. The swallowing reflex was evoked by repetitive electrical stimulation of the superior laryngeal nerve (SLN) and was identified by electromyographic activities from the mylohyoid muscle. Electrical stimulation was applied to the LRt or glutamate was injected into the LRt. The number of swallows was reduced, and the latency of the onset of the first swallow was increased during electrical stimulation near the middle of the rostrocaudal direction of the LRt. The number of swallows was reduced, and the latency of onset of the first swallow increased after microinjection of glutamate near the rostrocaudal center of the LRt. The present study suggests that the LRt is involved in control of the swallowing reflex.
Collapse
Affiliation(s)
- Tomohito Sakazume
- Clinical Examination, Field of Oral and Maxillofacial Surgery and Systemic Medicine, Course of Clinical Science, The Nippon Dental University Graduate School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuo-ku, Niigata 951-8580, Japan
| | - Yoshihide Satoh
- Department of Physiology, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuo-ku, Niigata 951-8580, Japan.
| | - Shogo Ohkoshi
- Clinical Examination, Field of Oral and Maxillofacial Surgery and Systemic Medicine, Course of Clinical Science, The Nippon Dental University Graduate School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuo-ku, Niigata 951-8580, Japan; Department of Internal Medicine, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuo-ku, Niigata 951-8580, Japan
| |
Collapse
|
4
|
Martvon L, Veternik M, Simera M, Kotmanova Z, Babalova L, Morris KF, Pitts T, Bolser DC, Poliacek I. Modeling and simulation of vagal afferent input of the cough reflex. Respir Physiol Neurobiol 2022; 301:103888. [PMID: 35307565 DOI: 10.1016/j.resp.2022.103888] [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: 11/18/2021] [Revised: 03/08/2022] [Accepted: 03/15/2022] [Indexed: 11/27/2022]
Abstract
We employed computational modeling to investigate previously conducted experiments of the effect of vagal afferent modulation on the cough reflex in an anesthetized cat animal model. Specifically, we simulated unilateral cooling of the vagus nerve and analyzed characteristics of coughs produced by a computational model of brainstem cough/respiratory neuronal network. Unilateral vagal cooling was simulated by a reduction of cough afferent input (corresponding to unilateral vagal cooling) to the cough network. All these attempts resulted in only mild decreases in investigated cough characteristics such as cough number, amplitudes of inspiratory and expiratory cough efforts in comparison with experimental data. Multifactorial alterations of model characteristics during cough simulations were required to approximate cough motor patterns that were observed during unilateral vagal cooling in vivo. The results support the plausibility of a more complex NTS processing system for cough afferent information than has been proposed.
Collapse
Affiliation(s)
- Lukas Martvon
- Medical Education Support Center, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia; Institute of Medical Biophysics, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
| | - Marcel Veternik
- Institute of Medical Biophysics, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia.
| | - Michal Simera
- Institute of Medical Biophysics, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
| | - Zuzana Kotmanova
- Institute of Medical Biophysics, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
| | - Lucia Babalova
- Clinic of Neurology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
| | - Kendall F Morris
- Department of Molecular Pharmacology and Physiology, College of Medicine, University of South Florida, Tampa, FL, USA
| | - Teresa Pitts
- Department of Neurological Surgery, Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, USA
| | - Donald C Bolser
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | - Ivan Poliacek
- Institute of Medical Biophysics, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
| |
Collapse
|
5
|
Kato K, Morinaga R, Yokoyama T, Fushuku S, Wakai J, Nakamuta N, Yamamoto Y. Effects of CO 2 on time-dependent changes in cardiorespiratory functions under sustained hypoxia. Respir Physiol Neurobiol 2022; 300:103886. [PMID: 35296417 DOI: 10.1016/j.resp.2022.103886] [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: 10/11/2021] [Revised: 02/16/2022] [Accepted: 03/09/2022] [Indexed: 11/18/2022]
Abstract
Hypercapnia in addition to hypoxia affects the mammalian cardiorespiratory system and has been suggested to exert its effects on cardiorespiratory function by slightly different mechanisms to hypoxia. In the present study, we examined cardiorespiratory changes in urethane-anesthetized rats under hypocapnic (Hypo, 10% O2), isocapnic (Iso, 10% O2 and 4% CO2), and hypercapnic (Hyper, 10% O2 and 8% CO2) hypoxia for 2 h to clarify the effects of CO2 on sustained hypoxia-induced cardiorespiratory responses. Respiratory frequency increased the most in Hypo and tidal volume in Hyper. Minute ventilation, a product of respiratory frequency and tidal volume, increased the most in the latter group. Regarding cardiovascular variables during the hypoxic exposure period, heart rate and mean blood pressure both markedly decreased in Hypo. However, decreases in these parameters were small in Iso, and both increased over the pre-exposure level in Hyper. The present results suggest that CO2 interferes with the hypoxia-activated neural pathway via another pathway under sustained exposure to hypoxia.
Collapse
Affiliation(s)
- Kouki Kato
- Center for Laboratory Animal Science, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Ryosuke Morinaga
- Department of Microscopic Anatomy and Cell Biology, Asahikawa Medical University, 2-1-1-1 Midorigaoka Higashi, Asahikawa, Hokkaido 078-8510, Japan
| | - Takuya Yokoyama
- Department of Anatomy (Cell Biology), Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate 028-3694, Japan
| | - Seigo Fushuku
- Center for Laboratory Animal Science, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Jun Wakai
- Department of Laboratory Animal Medicine, Institute for Biomedical Sciences, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate 028-3694, Japan
| | - Nobuaki Nakamuta
- Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, 18-8, Ueda 3-chome, Morioka, Iwate 020-8550, Japan
| | - Yoshio Yamamoto
- Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, 18-8, Ueda 3-chome, Morioka, Iwate 020-8550, Japan.
| |
Collapse
|
6
|
Bidirectional interactions between the baroreceptor reflex and arousal: an update. Sleep Med 2015; 16:210-6. [DOI: 10.1016/j.sleep.2014.10.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Revised: 09/15/2014] [Accepted: 10/08/2014] [Indexed: 11/23/2022]
|
7
|
Panneton WM, Gan Q, Le J, Livergood RS, Clerc P, Juric R. Activation of brainstem neurons by underwater diving in the rat. Front Physiol 2012; 3:111. [PMID: 22563319 PMCID: PMC3342523 DOI: 10.3389/fphys.2012.00111] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 04/04/2012] [Indexed: 01/10/2023] Open
Abstract
The mammalian diving response is a powerful autonomic adjustment to underwater submersion greatly affecting heart rate, arterial blood pressure, and ventilation. The bradycardia is mediated by the parasympathetic nervous system, arterial blood pressure is mediated via the sympathetic system and still other circuits mediate the respiratory changes. In the present study we investigate the cardiorespiratory responses and the brainstem neurons activated by voluntary diving of trained rats, and, compare them to control and swimming animals which did not dive. We show that the bradycardia and increase in arterial blood pressure induced by diving were significantly different than that induced by swimming. Neuronal activation was calculated after immunohistochemical processing of brainstem sections for Fos protein. Labeled neurons were counted in the caudal pressor area, the medullary dorsal horn, subnuclei of the nucleus tractus solitarii (NTS), the nucleus raphe pallidus (RPa), the rostroventrolateral medulla, the A5 area, the nucleus locus coeruleus, the Kölliker–Fuse area, and the external lateral and superior lateral subnuclei of the parabrachial nucleus. All these areas showed significant increases in Fos labeling when data from voluntary diving rats were compared to control rats and all but the commissural subnucleus of the NTS, A5 area, and RPa were significantly different from swimming rats. These data provide a substrate for more precise experiments to determine the role of these nuclei in the reflex circuits driving the diving response.
Collapse
Affiliation(s)
- W Michael Panneton
- Department of Pharmacological and Physiological Science, St. Louis University School of Medicine St. Louis, MO, USA
| | | | | | | | | | | |
Collapse
|
8
|
Ahlgren JK, Hayward LF. Daily voluntary exercise alters the cardiovascular response to hemorrhage in conscious male rats. Auton Neurosci 2011; 160:42-52. [PMID: 21215710 PMCID: PMC3034809 DOI: 10.1016/j.autneu.2010.11.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 08/30/2010] [Accepted: 11/19/2010] [Indexed: 01/03/2023]
Abstract
The present study tested the hypothesis that voluntary wheel-exercised rats would better tolerate severe hemorrhage (HEM) compared to age matched sedentary (SED) controls. Conscious rats housed with (EX, n = 8) or without (SED, n = 8) a running wheel for 6 weeks underwent a 30% total blood volume HEM over 15 min and were euthanized 90 min later and brain tissue was processed for Fos-like immunoreactivity (FLI). Both EX and SED groups displayed typical responses to HEM (initial tachycardia followed by decreased HR and MAP) but at the end of HEM, mean arterial pressure (93 ± 6 vs 58 ± 3 mm Hg) and heart rate (316 ± 17 vs. 247 ± 22 bpm,) were higher in the EX vs. SED animals and 60 min following the end of HEM, HR remained significantly elevated in the EX vs SED animals. The altered HR response to HEM in the EX animals was linked to a significant difference in sympatho-vagal drive identified by heart rate variability analysis and an augmented baroreflex response to hypotension tested in a separate group of animals (n = 4-5/group). In many of the brain regions analyzed, EX rats displayed lower levels of FLI compared to SED rats. Significantly lower levels of FLI in the EX vs SED rats were identified in the middle and caudal external lateral subnucleus of the lateral parabrachial nucleus and the dorsal cap of the hypothalamic paraventricular nucleus. These results suggest that enhanced tolerance to HEM following daily exercise may result from an EX-induced reduction in excitation or exaggerated inhibition in central circuits involved in autonomic control.
Collapse
Affiliation(s)
- Joslyn K Ahlgren
- Department of Physiological Sciences, University of FL, Gainesville, 32610, United States
| | | |
Collapse
|
9
|
Niu JG, Yokota S, Tsumori T, Qin Y, Yasui Y. Glutamatergic lateral parabrachial neurons innervate orexin-containing hypothalamic neurons in the rat. Brain Res 2010; 1358:110-22. [DOI: 10.1016/j.brainres.2010.08.056] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 07/26/2010] [Accepted: 08/17/2010] [Indexed: 12/12/2022]
|
10
|
Hengen KB, Behan M, Carey HV, Jones MV, Johnson SM. Hibernation induces pentobarbital insensitivity in medulla but not cortex. Am J Physiol Regul Integr Comp Physiol 2009; 297:R1028-36. [PMID: 19675281 DOI: 10.1152/ajpregu.00239.2009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The 13-lined ground squirrel (Ictidomys tridecemlineatus), a hibernating species, is a natural model of physiological adoption to an extreme environment. During torpor, body temperature drops to 0-4 degrees C, and the cortex is electrically silent, yet the brain stem continues to regulate cardiorespiratory function. The mechanisms underlying selective inhibition in the brain during torpor are not known. To test whether altered GABAergic function is involved in regional and seasonal differences in neuronal activity, cortical and medullary slices from summer-active (SA) and interbout aroused (IBA) squirrels were placed in a standard in vitro recording chamber. Silicon multichannel electrodes were placed in cortex, ventral respiratory column (VRC), and nucleus tractus solitarius (NTS) to record spontaneous neuronal activity. In slices from IBA squirrels, bath-applied pentobarbital sodium (300 microM) nearly abolished cortical neuronal activity, but VRC and NTS neuronal activity was unaltered. In contrast, pentobarbital sodium (300 microM) nearly abolished all spontaneous cortical, VRC, and NTS neuronal activity in slices from SA squirrels. Muscimol (20 microM; GABA(A) receptor agonist) abolished all neuronal activity in cortical and medullary slices from both IBA and SA squirrels, thereby demonstrating the presence of functional GABA(A) receptors. Pretreatment of cortical slices from IBA squirrels with bicuculline (100 microM; GABA(A) receptor antagonist) blocked pentobarbital-dependent inhibition of spontaneous neuronal activity. We hypothesize that GABA(A) receptors undergo a seasonal modification in subunit composition, such that cardiorespiratory neurons are uniquely unaffected by surges of an endogenous positive allosteric modulator.
Collapse
Affiliation(s)
- Keith B Hengen
- School of Veterinary Medicine, University of Wisconsin, Madison, Madison, Wisconsin 53706, USA
| | | | | | | | | |
Collapse
|
11
|
Díaz-Casares A, López-González MV, Peinado-Aragonés CA, Lara JP, González-Barón S, Dawid-Milner MS. Role of the parabrachial complex in the cardiorespiratory response evoked from hypothalamic defense area stimulation in the anesthetized rat. Brain Res 2009; 1279:58-70. [DOI: 10.1016/j.brainres.2009.02.085] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Revised: 02/27/2009] [Accepted: 02/27/2009] [Indexed: 11/25/2022]
|
12
|
Abstract
Cough is the most common symptom for which individuals seek medical attention and spend health-care dollars. Despite the burden induced by cough, the current treatments for cough are only partially effective. Delineating the sites and mechanisms in the cough central network for changes in the cough reflex could lead to new therapeutic strategies and drug target sites for more effective treatments. The first synaptic target in the CNS for the cough-related sensory input is the second-order neurons in the nucleus tractus solitarius (NTS); these neurons reorganize the primary sensory information into a coherent output. The NTS neurons have been shown to undergo neuroplasticity under a variety of conditions, such as respiratory disorders, stress, and exposures to environmental pollutants. The NTS contains a rich innervation of substance P immunoreactive nerve terminals, suggesting that substance P might be important in altered cough reflex response. This chapter summarizes our current findings on the role of substance P in enhanced cough reflex as well as the potential NTS targets for the action of substance P.
Collapse
Affiliation(s)
- C-Y Chen
- Department of Pharmacology, University of California, Davis School of Medicine, 4150 V Street, 1104 PSSB, Sacramento, CA 95817, USA
| | | | | | | |
Collapse
|
13
|
Krause EG, Curtis KS, Markle JP, Contreras RJ. Oestrogen affects the cardiovascular and central responses to isoproterenol of female rats. J Physiol 2007; 582:435-47. [PMID: 17430989 PMCID: PMC2075287 DOI: 10.1113/jphysiol.2007.131151] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
This study examined the influence of oestrogen on cardiovascular responses to hypotension produced by administration of isoproterenol (Isop) and on neural activation in hindbrain nuclei mediating these responses. We first measured mean arterial pressure (MAP) and heart rate (HR) after administration of isoproterenol, a beta-adrenergic agonist that increases circulating levels of AngII, in ovariectomized (OVX) rats treated with oestradiol benzoate (EB). We then evaluated EB effects on Isop-induced Fos immunoreactivity (Fos-IR) in the hindbrain baroreflex circuit. To control for weight loss associated with oestrogen replacement in OVX rats, we food restricted a separate group of OVX rats and evaluated Isop-induced changes in MAP, HR and Fos-IR. The depressor response to Isop was significantly attenuated by EB, which also produced a disproportionate increase in HR. These effects were not secondary to loss of body weight after EB treatment, because cardiovascular responses to Isop in food restricted rats were similar to those in OVX rats treated with the oil vehicle. Isop significantly increased Fos-IR in the nucleus of the solitary tract (NTS), area postrema (AP), rostral ventrolateral medulla (RVLM), and lateral parabrachial nucleus (lPBN); however, EB significantly attenuated the increase in the AP and in the lPBN. Again, these effects were not secondary to body weight loss, because food restricted rats had the same pattern of Fos-IR as did rats treated with the oil vehicle. These results suggest that EB modifies cardiovascular responses to Isop, possibly by decreasing activation of the AP and lPBN.
Collapse
Affiliation(s)
- Eric G Krause
- Department of Psychology, Program in Neuroscience, Florida State University, Tallahassee, FL 32306-1270 USA
| | | | | | | |
Collapse
|
14
|
Hayward LF. Midbrain modulation of the cardiac baroreflex involves excitation of lateral parabrachial neurons in the rat. Brain Res 2007; 1145:117-27. [PMID: 17355874 PMCID: PMC1904493 DOI: 10.1016/j.brainres.2007.01.140] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Revised: 01/26/2007] [Accepted: 01/27/2007] [Indexed: 02/06/2023]
Abstract
Activation of the dorsal periaqueductal gray (PAG) evokes defense-like behavior including a marked increase in sympathetic drive and resetting of baroreflex function. The goal of this study was to investigate the role of the lateral parabrachial nucleus (LPBN) in mediating dorsal PAG modulation of the arterial baroreflex. Reflex responses were elicited by electrical stimulation of the aortic depressor nerve (ADN) at 5 Hz or 15 Hz in urethane anesthetized rats (n=18). Electrical stimulation of the dorsal PAG at 10 Hz did not alter baseline mean arterial pressure (MAP) but did significantly attenuate baroreflex control of heart rate (HR) evoked by low frequency ADN stimulation. Alternatively, 40 Hz dorsal PAG stimulation increased baseline MAP (43+/-3 mm Hg) and HR (33+/-3 bpm) and attenuated baroreflex control of HR at both ADN stimulation frequencies. Reflex control of MAP was generally unchanged by dorsal PAG stimulation. Bilateral inhibition of neurons in LPBN area (n=6) with muscimol (0.45 nmol per side) reduced dorsal PAG-evoked increases in MAP and HR by 50+/-4% and 95+/-4%, respectively, and significantly reduced, but did not completely eliminate dorsal PAG attenuation of the cardiac baroreflex. Bilateral blockade of glutamate receptors in the LPBN area (n=6) with kynurenic acid (1.8 nmol) had a similar effect on dorsal PAG-evoked increases in MAP, HR and cardiac baroreflex function. Reflex control of MAP was unchanged with either treatment. These findings suggest that the LPBN area is one of several brainstem regions involved in descending modulation of the cardiac baroreflex function during defensive behavior.
Collapse
Affiliation(s)
- Linda F Hayward
- University of Florida, College of Veterinary Medicine, Department of Physiological Sciences and McKnight Brain Institute, PO 100144 Gainesville, FL 32610-1044, USA.
| |
Collapse
|
15
|
Bonham AC, Sekizawa SI, Chen CY, Joad JP. Plasticity of brainstem mechanisms of cough. Respir Physiol Neurobiol 2006; 152:312-9. [PMID: 16554189 DOI: 10.1016/j.resp.2006.02.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2005] [Revised: 02/07/2006] [Accepted: 02/09/2006] [Indexed: 11/27/2022]
Abstract
The cough reflex is a brainstem reflex, consisting of specific sensory afferent nerves which trigger the reflex, by transmitting the sensory input over vagal or laryngeal nerves to a brainstem circuitry which processes and ultimately transforms the sensory input into a complex motor output to generate cough. The first synaptic target for the primary cough-related sensory input is the second-order neurons in the nucleus tractus solitarius (NTS). This position in the reflex pathway and intricate local circuits within the nucleus make it a strategic site where the sensory information can be modified. Plasticity at this synapse will change the nature of the output--exaggerating it, suppressing it or transforming it into some other complex pattern. This review integrates evidence implicating the NTS in exaggerated cough with proof of the concept that NTS neurons undergo plasticity to contribute to an exaggeration of cough.
Collapse
Affiliation(s)
- Ann C Bonham
- Department of Pharmacology, University of California, Davis School of Medicine, 4150 V Street, 1104 PSSB, Sacramento, CA 95817, USA.
| | | | | | | |
Collapse
|
16
|
Bonham AC, Chen CY, Sekizawa SI, Joad JP. Plasticity in the nucleus tractus solitarius and its influence on lung and airway reflexes. J Appl Physiol (1985) 2006; 101:322-7. [PMID: 16484366 DOI: 10.1152/japplphysiol.00143.2006] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The nucleus tractus solitarius (NTS) is the first central nervous system (CNS) site for synaptic contact of the primary afferent fibers from the lungs and airways. The signal processing at these synapses will determine the output of the sensory information from the lungs and airways to all downstream synapses in the reflex pathways. The second-order NTS neurons bring to bear their own intrinsic and synaptic properties to temporally and spatially integrate the sensory information with inputs from local networks, higher brain regions, and circulating mediators, to orchestrate a coherent reflex output. There is growing evidence that NTS neurons share the rich repertoire of forms of plasticity demonstrated throughout the CNS. This review focuses on existing evidence for plasticity in the NTS, potential targets for plasticity in the NTS, and the impact of this plasticity on lung and airway reflexes.
Collapse
Affiliation(s)
- Ann C Bonham
- Department of Medical Pharmacology, University of California, Davis, CA, USA.
| | | | | | | |
Collapse
|
17
|
Boscan P, Dutschmann M, Herbert H, Paton JFR. Neurokininergic mechanism within the lateral crescent nucleus of the parabrachial complex participates in the heart-rate response to nociception. J Neurosci 2005; 25:1412-20. [PMID: 15703395 PMCID: PMC6725996 DOI: 10.1523/jneurosci.4075-04.2005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We wanted to ascertain whether the lateral parabrachial nucleus was involved in mediating the heart-rate response evoked during stimulation of somatic nociceptors. Reversible inactivation of the lateral parabrachial nucleus, using a GABA(A) agonist, reduced the reflex tachycardia evoked during noxious (mechanical) stimulation of the forelimb by approximately 50%. The same effect was observed after blockade of neurokinin 1 receptors within the lateral parabrachial nucleus, indicating a possible involvement for substance P as a neurotransmitter. Immunocytochemistry revealed a strong expression of substance P-immunoreactive fibers and boutons in all lateral subnuclei, but they were particularly dense in the lateral crescent subnucleus. Histological verification showed that the most effective injection sites for attenuating the noxious-evoked tachycardia were all placed in or near to the lateral crescent nucleus of the lateral parabrachial complex. Many single units recorded from this region were activated by high-intensity brachial nerve stimulation. The brachial nerve evoked firing responses of some of these neurons was reversibly reduced after local delivery of a neurokinin 1 receptor antagonist. However, only a minority of these neurons followed a paired-pulse stimulation protocol applied to the spinal cord, suggesting a predominance of indirect projections from the spinal cord to the parabrachial nucleus. We conclude that the cardiac component of the response to somatic nociception involves indirect spinal pathways that most likely excite neurons located in the lateral crescent nucleus of the parabrachial complex via activation of neurokinin 1 receptors.
Collapse
Affiliation(s)
- Pedro Boscan
- Department of Physiology, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, United Kingdom
| | | | | | | |
Collapse
|
18
|
Abstract
Mapping with local lesions, electrical or chemical stimulation, or recording evoked field potentials or unit spikes revealed localized representations of cardiovascular functions in the cerebellum. In this review, which is based on literatures in the field (including our own publications), I propose that the cerebellum contains five distinct modules (cerebellar corticonuclear microcomplexes) dedicated to cardiovascular control. First, a discrete rostral portion of the fastigial nucleus and the overlying medial portion of the anterior vermis (lobules I, II and III) conjointly form a module that controls the baroreflex. Second, anterior vermis also forms a microcomplex with the parabrachial nucleus. Third, a discrete caudal portion of the fastigial nucleus and the overlying medial portion of the posterior vermis (lobules VII and VIII) form another module controlling the vestibulosympathetic reflex. Fourth, the medial portion of the uvula may form a module with the nucleus tractus solitarius and parabrachial nucleus. Fifth, the lateral edge of the nodulus and the uvula, together with the parabrachial nucleus and vestibular nuclei, forms a cardiovascular microcomplex that controls the magnitude and/or timing of sympathetic nerve responses and stability of the mean arterial blood pressure during changes of head position and body posture. The lateral nodulus-uvula appears to be an integrative cardiovascular control center involving both the baroreflex and the vestibulosympathetic reflex.
Collapse
Affiliation(s)
- Naoko Nisimaru
- Department of Physiology, Faculty of Medicine, University of Oita, Oita 879-5593, Japan.
| |
Collapse
|
19
|
Huang J, Spier AD, Pickel VM. 5-HT3A receptor subunits in the rat medial nucleus of the solitary tract: subcellular distribution and relation to the serotonin transporter. Brain Res 2005; 1028:156-69. [PMID: 15527741 DOI: 10.1016/j.brainres.2004.09.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2004] [Indexed: 10/26/2022]
Abstract
The 5-hydroxytryptamine 3 (5HT3) receptor is a serotonin-gated ion channel implicated in reflex regulation of autonomic functions within the nucleus of the solitary tract (NTS). To determine the relevant sites for 5-HT3 receptor mediated transmission in this region, we used electron microscopic immunocytochemistry to examine the subcellular distribution of the 5HT3 receptor subunit A (5HT3A) in relation to the serotonin transporter (SERT) in the intermediate medial NTS (mNTS) of rat brain. The 5HT3A immunolabeling was detected in many axonal as well as somatodendritic and glial profiles. The axonal profiles included small axons and axon terminals in which the 5HT3A immunoreactivity was localized to membranes of synaptic vesicles and extrasynaptic plasma membranes. In dendrites and glia, the 5HT3A immunoreactivity was located on the plasma membranes or in association with membranous cytoplasmic organelles. The dendritic plasmalemmal 5HT3A labeling was prominent within and near excitatory-type synapses from terminals including those that resemble vagal afferents. The 5HT3A-labeled glial processes apposed 5HT3A-immunoreactive axonal and dendritic profiles, some of which also contained SERT. Terminals containing 5-HT3A and/or SERT were among those providing synaptic input to 5HT3A-labeled dendrites. Thus, 5HT3A has a subcellular distribution consistent with the involvement of 5-HT3 receptors in modulation of both presynaptic release and postsynaptic responses of mNTS neurons, some of which are serotonergic. The results further suggest that the neuronal as well as glial 5HT3 receptors can be activated by release of serotonin from presynaptic terminals or by diffusion facilitated by SERT distribution at a distant from the synapse.
Collapse
Affiliation(s)
- Jie Huang
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Medical College of Cornell University, 411 East 69th Street, New York, NY 10021, USA
| | | | | |
Collapse
|
20
|
Hayward LF, Castellanos M, Davenport PW. Parabrachial neurons mediate dorsal periaqueductal gray evoked respiratory responses in the rat. J Appl Physiol (1985) 2004; 96:1146-54. [PMID: 14594859 DOI: 10.1152/japplphysiol.00903.2003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The neural substrates mediating autonomic components of the behavioral defense response reside in the periaqueductal gray (PAG). The cardiovascular components of the defense response evoked from the dorsal PAG (DPAG) have been well described and are dependent, in part, on the integrity of neurons in the region of the parabrachial nucleus as well as the rostral ventrolateral medulla. Descending pathways mediating the ventilatory response associated with activation of DPAG neurons are unknown. The present study was undertaken to test the hypothesis that parabrachial area neurons are also involved in mediating the respiratory response to DPAG stimulation. In urethane-anesthetized, spontaneously breathing rats, electrical stimulation of the DPAG significantly increased respiratory rate, arterial pressure, and heart rate. Changes in respiratory frequency were associated with significant decreases in inspiratory and expiratory durations. After bilateral inhibition of neurons in the lateral parabrachial nucleus (LPBN) region with 5 mM muscimol ( n = 6), DPAG-evoked increases in respiration and heart rate were attenuated by 90 ± 6 and 72 ± 13%, respectively. The pressor response evoked by DPAG stimulation, however, was attenuated by only 57 ± 6%. Bilateral blockade of glutamate receptors with 20 mM kynurenic acid ( n = 6) in the LPBN also markedly attenuated DPAG-evoked increases in respiration and heart rate (65 ± 15 and 53 ± 9% reduction, respectively) but only modestly changed the DPAG-evoked pressor response (34 ± 16% reduction). These results demonstrate that LPBN neurons play a significant role in the DPAG-mediated respiratory component of behavioral defense responses. This finding supports previous work demonstrating that the dorsolateral pons plays a significant role in mediating most physiological adjustments associated with activation of the DPAG.
Collapse
Affiliation(s)
- Linda F Hayward
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32601, USA.
| | | | | |
Collapse
|
21
|
Hayward LF, Castellanos M. Increased c-Fos expression in select lateral parabrachial subnuclei following chemical versus electrical stimulation of the dorsal periaqueductal gray in rats. Brain Res 2003; 974:153-66. [PMID: 12742633 DOI: 10.1016/s0006-8993(03)02573-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The parabrachial nucleus (PBN) is located in the rostral dorsolateral pons and has been identified as a critical relay for cardiovascular responses (sympathoexcitation and baroreflex attenuation) evoked by the dorsal periaqueductal gray (PAG). We examined the pattern of c-Fos protein immunoreactivity throughout the rostral-caudal extent of the PBN in four groups of anesthetized male Sprague-Dawley rats to identify the specific PBN regions activated by dorsal PAG stimulation. Both electrical stimulation and chemical (0.3 mM bicuculline methobromide) activation of the dorsal PAG elicited a selective increase in Fos-like immunoreactivity (FLI) in the superior lateral and central lateral subnuclei of the rostral lateral PBN (LPBN) relative to surgery and blood pressure control groups. In the middle LPBN chemical stimulation of the dorsal PAG selectively increased FLI in the central lateral subnucleus while electrical stimulation increased FLI in the Kolliker-Fuse area only. Finally, in the caudal LPBN only electrical stimulation of the dorsal PAG induced significant changes in FLI above control. Significant changes in FLI in the medial PBN were not observed under any experimental conditions. These results confirm neuroanatomical data demonstrating that neurons in superior lateral and central lateral subnuclei of the rostral and middle LPBN are the primary targets of the dorsal PAG. Our results also demonstrate that this descending projection to the central lateral and superior lateral subnuclei of the LPBN is in part excitatory. Finally, our results raise the possibility that neurons in the central lateral subnucleus of the middle and rostral LPBN are integrally involved in descending modulation of sympathetic drive associated with dorsal PAG activation.
Collapse
Affiliation(s)
- Linda F Hayward
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, 1600 SW Archer Rd., PO 100144, Gainesville 32601-0144, USA.
| | | |
Collapse
|