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Chang YC, Chen CM, Lay IS, Lee YC, Tu CH. The effects of laser acupuncture dosage at PC6 (Neiguan) on brain reactivity: a pilot resting-state fMRI study. Front Neurosci 2023; 17:1264217. [PMID: 37901421 PMCID: PMC10600496 DOI: 10.3389/fnins.2023.1264217] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 09/27/2023] [Indexed: 10/31/2023] Open
Abstract
Previous studies indicated that laser acupuncture (LA) may effectively treat various medical conditions. However, brain responses associated with LA intervention have not been fully investigated. This study is focused on the effect of LA with different energy density (ED) in brain using resting-state functional magnetic resonance imaging (fMRI). We hypothesized that different ED would elicit various brain responses. We enrolled healthy adults participants and selected bilateral PC6 (Neiguan) as the intervention points. LA was applied, respectively, with ED of 0, 7.96, or 23.87 J/cm2. Two 500-s resting-state fMRI scans were acquired before and after intervention, respectively. The functional connectivity (FC) was calculated between autonomic nerve system-regulation associated brainstem structures and other brain regions. Compared to other dosages, the FC between rostral ventrolateral medulla and orbitofrontal cortex has more enhanced; the FC between caudal ventrolateral medulla, nucleus of the solitary tract/nucleus ambiguus, and dorsal motor nucleus of the vagus and somatosensory area has more weakened when ED was 23.87 J/cm2. Different dosages of LA have demonstrated varied regions of FC changes between regions of interest and other brain areas, which indicated that variations in EDs might influence the clinical efficacy and subsequent impacts through distinct neural pathways within the brain.
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Affiliation(s)
- Yi-Chuan Chang
- Graduate Institute of Acupuncture Science, College of Chinese Medicine, China Medical University, Taichung, Taiwan
- Department of Chinese Medicine, China Medical University Beigang Hospital, Yunlin, Taiwan
| | - Chun-Ming Chen
- Department of Medical Imaging, China Medical University Hospital, Taichung, Taiwan
| | - Ing-Shiow Lay
- Department of Chinese Medicine, China Medical University Beigang Hospital, Yunlin, Taiwan
- School of Post-Baccalaureate Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Yu-Chen Lee
- Graduate Institute of Acupuncture Science, College of Chinese Medicine, China Medical University, Taichung, Taiwan
- School of Chinese Medicine, China Medical University, Taichung, Taiwan
- Department of Chinese Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Cheng-Hao Tu
- Graduate Institute of Acupuncture Science, College of Chinese Medicine, China Medical University, Taichung, Taiwan
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2
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Peralta-Malváez L, Turnbull A, Anthony M, Adeli E, Lin FV. CCA identifies a neurophysiological marker of adaptation capacity that is reliably linked to internal locus of control of cognition in amnestic MCI. GeroScience 2023:10.1007/s11357-023-00730-8. [PMID: 36697886 PMCID: PMC10400522 DOI: 10.1007/s11357-023-00730-8] [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: 10/13/2022] [Accepted: 01/09/2023] [Indexed: 01/27/2023] Open
Abstract
Locus of control (LOC) describes whether an individual thinks that they themselves (internal LOC) or external factors (external LOC) have more influence on their lives. LOC varies by domain, and a person's LOC for their intellectual capacities (LOC-Cognition) may be a marker of resilience in older adults at risk for dementia, with internal LOC-Cognition relating to better outcomes and improved treatment adherence. Vagal control, a key component of parasympathetic autonomic nervous system (ANS) regulation, may reflect a neurophysiological biomarker of internal LOC-Cognition. We used canonical correlation analysis (CCA) to identify a shared neurophysiological marker of ANS regulation from electrocardiogram (during auditory working memory) and functional connectivity (FC) data. A canonical variable from root mean square of successive differences (RMSSD) time series and between-network FC was significantly related to internal LOC-Cognition (β = 0.266, SE = 0.971, CI = [0.190, 4.073], p = 0.031) in 65 participants (mean age = 74.7, 32 female) with amnestic mild cognitive impairment (aMCI). Follow-up data from 55 of these individuals (mean age = 73.6, 22 females) was used to show reliability of this relationship (β = 0.271, SE = 0.971, CI = [0.033, 2.630], p = 0.047), and a second sample (40 participants with aMCI/healthy cognition, mean age = 72.7, 24 females) showed that the canonical vector biomarker generalized to visual working memory (β = 0.36, SE = 0.136, CI = [0.023, 0.574], p = 0.037), but not inhibition task RMSSD data (β = 0.08, SE = 1.486, CI = [- 0.354, 0.657], p = 0.685). This canonical vector may represent a biomarker of autonomic regulation that explains how some older adults maintain internal LOC-Cognition as dementia progresses. Future work should further test the causality of this relationship and the modifiability of this biomarker.
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Affiliation(s)
- Lizbeth Peralta-Malváez
- CogT Lab, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, 94305, USA
| | - Adam Turnbull
- CogT Lab, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, 94305, USA. .,Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY, 14627, USA.
| | - Mia Anthony
- CogT Lab, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, 94305, USA.,Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY, 14627, USA
| | - Ehsan Adeli
- CogT Lab, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, 94305, USA
| | - F Vankee Lin
- CogT Lab, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, 94305, USA
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3
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De Zorzi L, Ranfaing S, Roux C, Honoré J, Sequeira H. Impact of visual eccentricity on emotional reactivity: implications for anxious and depressive symptomatology. JOURNAL OF AFFECTIVE DISORDERS REPORTS 2022. [DOI: 10.1016/j.jadr.2021.100304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Minic Z, O’Leary DS, Reynolds CA. Spinal Reflex Control of Arterial Blood Pressure: The Role of TRP Channels and Their Endogenous Eicosanoid Modulators. Front Physiol 2022; 13:838175. [PMID: 35283783 PMCID: PMC8904930 DOI: 10.3389/fphys.2022.838175] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/26/2022] [Indexed: 01/14/2023] Open
Abstract
The spinal cord is an important integrative center for blood pressure control. Spinal sensory fibers send projections to sympathetic preganglionic neurons of the thoracic spinal cord and drive sympathetically-mediated increases in blood pressure. While these reflexes responses occur in able-bodied individuals, they are exaggerated following interruption of descending control - such as occurs following spinal cord injury. Similar reflex control of blood pressure may exist in disease states, other than spinal cord injury, where there is altered input to sympathetic preganglionic neurons. This review primarily focuses on mechanisms wherein visceral afferent information traveling via spinal nerves influences sympathetic nerve activity and blood pressure. There is an abundance of evidence for the widespread presence of this spinal reflex arch originating from virtually every visceral organ and thus having a substantial role in blood pressure control. Additionally, this review highlights specific endogenous eicosanoid species, which modulate the activity of afferent fibers involved in this reflex, through their interactions with transient receptor potential (TRP) cation channels.
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Affiliation(s)
- Zeljka Minic
- Department of Emergency Medicine Wayne State University School of Medicine, Detroit, MI, United States
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
| | - Donal S. O’Leary
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Christian A. Reynolds
- Department of Emergency Medicine Wayne State University School of Medicine, Detroit, MI, United States
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
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5
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Lee Y, Walsh RJ, Fong MWM, Sykora M, Doering MM, Wong AWK. Heart rate variability as a biomarker of functional outcomes in persons with acquired brain injury: Systematic review and meta-analysis. Neurosci Biobehav Rev 2021; 131:737-754. [PMID: 34626686 PMCID: PMC9006352 DOI: 10.1016/j.neubiorev.2021.10.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 09/30/2021] [Accepted: 10/01/2021] [Indexed: 01/09/2023]
Abstract
This review aimed to quantify correlations between heart rate variability (HRV) and functional outcomes after acquired brain injury (ABI). We conducted a literature search from inception to January 2020 via electronic databases, using search terms with HRV, ABI, and functional outcomes. Meta-analyses included 16 studies with 906 persons with ABI. Results demonstrated significant associations: Low frequency (LF) (r = -0.28) and SDNN (r = -0.33) with neurological function; LF (r = -0.33), High frequency (HF) (r = -0.22), SDNN (r = -0.22), and RMSSD (r = -0.23) with emotional function; and LF (r = 0.34), HF (r = 0.41 to 0.43), SDNN (r = 0.43 to 0.51), and RMSSD (r = 0.46) with behavioral function. Results indicate that higher HRV is related to better neurological, emotional, and behavioral functions after ABI. In addition, persons with stroke showed lower HF (SMD = -0.50) and SDNN (SMD = -0.75) than healthy controls. The findings support the use of HRV as a biomarker to facilitate precise monitoring of post-ABI functions.
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Affiliation(s)
- Yejin Lee
- Program in Occupational Therapy, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - Ryan J Walsh
- Program in Occupational Therapy, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - Mandy W M Fong
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63108, USA.
| | - Marek Sykora
- Department of Neurology, St. John's Hospital, Vienna, Austria; Medical Faculty, Sigmund Freud University, Vienna, Austria; Department of Neurology, Comenius University in Bratislava, Bratislava, Slovakia.
| | - Michelle M Doering
- Bernard Becker Medical Library, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - Alex W K Wong
- Center for Rehabilitation Outcomes Research, Shirley Ryan AbilityLab, Chicago, IL, 60611, USA; Department of Physical Medicine and Rehabilitation and Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
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Toepp SL, Turco CV, Locke MB, Nicolini C, Ravi R, Nelson AJ. The Impact of Glucose on Corticospinal and Intracortical Excitability. Brain Sci 2019; 9:brainsci9120339. [PMID: 31775377 PMCID: PMC6955876 DOI: 10.3390/brainsci9120339] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/20/2019] [Accepted: 11/22/2019] [Indexed: 01/08/2023] Open
Abstract
Neurotransmission is highly dependent on the availability of glucose-derived energy, although it is unclear how glucose availability modulates corticospinal and intracortical excitability as assessed via transcranial magnetic stimulation (TMS). In this double-blinded placebo-controlled study, we tested the effect of acute glucose intake on motor-evoked potential (MEP) recruitment curves, short-interval intracortical inhibition (SICI), short-latency afferent inhibition (SAI) and long-latency afferent inhibition (LAI). Eighteen healthy males participated in four sessions. Session 1 involved acquisition of an individualized blood glucose response curve. This allowed measurements to be time-locked to an individualized glucose peak after consuming one of three drinks during the subsequent three sessions. Participants were administered a 300 mL concealed solution containing 75 g of glucose, sucralose, or water in separate sessions. Dependent measures were assessed at baseline and twice after drinking the solution. Secondary measures included blood glucose and mean arterial pressure. Corticospinal excitability and blood pressure increased following the drink across all treatments. No changes were observed in SICI, SAI or LAI. There was no rise in corticospinal excitability that was specific to the glucose drink, suggesting that acute changes in glucose levels do not necessarily alter TMS measures of corticospinal or intracortical excitability.
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Foffani G, Obeso JA. A Cortical Pathogenic Theory of Parkinson's Disease. Neuron 2019; 99:1116-1128. [PMID: 30236282 DOI: 10.1016/j.neuron.2018.07.028] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 06/14/2018] [Accepted: 07/17/2018] [Indexed: 01/17/2023]
Abstract
In Parkinson's disease, the progressive neurodegeneration of nigrostriatal dopaminergic neurons in the substantia nigra pars compacta (SNc) is associated with classic motor features, which typically have a focal onset. Since a defined somatotopic arrangement in the SNc has not been recognized, this focal motor onset is unexplained and hardly justified by current pathogenic theories of bottom-up disease progression (Braak's hypothesis, prionopathy). Here we propose that corticostriatal activity may represent a critical somatotopic "stressor" for nigrostriatal terminals, ultimately driving retrograde nigrostriatal degeneration and leading to focal motor onset and progression of Parkinson's disease. As a pathogenic mechanism, corticostriatal activity may promote secretion of striatal extracellular alpha-synuclein, favoring its pathological aggregation at vulnerable dopaminergic synapses. A similar pathogenic process may occur at corticofugal projections to the medulla oblongata and other vulnerable structures, thereby contributing to the bottom-up progression of Lewy pathology. This cortical pathogenesis may co-exist with bottom-up mechanisms, adding an integrative top-down perspective to the quest for the factors that impinge upon the vulnerability of dopaminergic cells in the onset and progression of Parkinson's disease.
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Affiliation(s)
- Guglielmo Foffani
- CINAC, Hospital Universitario HM Puerta del Sur, Móstoles, Universidad CEU-San Pablo, Madrid, Spain; Hospital Nacional de Parapléjicos, Toledo, Spain.
| | - José A Obeso
- CINAC, Hospital Universitario HM Puerta del Sur, Móstoles, Universidad CEU-San Pablo, Madrid, Spain; CIBERNED, Instituto de Salud Carlos III, Madrid, Spain.
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Christensen JF, Gomila A. Introduction: Art and the brain: From pleasure to well-being. PROGRESS IN BRAIN RESEARCH 2018; 237:xxvii-xlvi. [PMID: 29779754 DOI: 10.1016/s0079-6123(18)30032-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Empirical aesthetics in general, and neuroaesthetics in particular, have been very much influenced by Berlyne's psychobiological program. For him, aesthetic appreciation involved the brain's reward and aversion systems. From this point of view, art constitutes a set of potentially rewarding stimuli. Research has certainly made great advances in understanding how the process of artistic valuation takes places, and which brain circuits are involved in generating the pleasure we obtain from artistic practices, performances, and works. But it also suggests that pleasure is not the only effect of the arts. The evidence rather suggests that the arts have other cognitive and emotional effects which are closely related to human psychobiological health and well-being. These are: (1) attentional focus and flow, (2) affective experience, (3) emotion through imagery, (4) interpersonal communication, (5) self-intimation, and (6) social bonding. These effects are beneficial and contribute to the individual's biopsychological health and well-being. The fact that artistic practice has these effects helps explain why the arts are so important to human life, and why they developed in the first place, i.e., as ways to foster these effects. Therefore, a biopsychological science of the arts is emerging, according to which the arts can be conceptualized as an important system of external self-regulation, as a set of activities that contribute to our homeostasis and well-being.
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Affiliation(s)
- Julia F Christensen
- BIAS Team (Prof. Manos Tsakiris), The Warburg Institute, School of Advanced Study, University of London, London, United Kingdom.
| | - Antoni Gomila
- Ed. Beatriu de Pinós, University of the Balearic Islands, Palma, Spain
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da Silva FTG, Browne RAV, Pinto CB, Saleh Velez FG, do Egito EST, do Rêgo JTP, da Silva MR, Dantas PMS, Fregni F. Transcranial direct current stimulation in individuals with spinal cord injury: Assessment of autonomic nervous system activity. Restor Neurol Neurosci 2017; 35:159-169. [PMID: 28282844 DOI: 10.3233/rnn-160685] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND We hypothesized in this study that transcranial direct current stimulation (tDCS) of primary motor cortex could exert top-down modulation over subcortical systems associated with autonomic control and thus be useful to revert some of the dysfunctional changes found in the autonomic nervous system (ANS) of subjects with spinal cord injuries (SCI). OBJECTIVE To explore the acute effect of tDCS on ANS indexed by Heart Rate Variability (HRV) in individuals with SCI and analyze whether this effect depends on the gender, degree, level and time of injury. METHODS In this randomized, placebo-controlled, crossover, double-blinded study, 18 adults with SCI (32.9±7.9 years old) were included; the intervention consisted of a single 12-minute session of active tDCS (anodal, 2 mA) and a control session of sham tDCS applied over Cz (bihemispheric motor cortex). HRV was calculated using spectral analysis. Low-frequency (LF), high-frequency (HF), and LF/HF ratio variables were evaluated before, during, and post tDCS. RESULTS A two-way repeated measures ANOVA showed that after active (anodal) stimulation, LF/HF ratio was significantly increased (P = 0.013). There was a trend for an interaction between time and stimulation for both LF and HF (P = 0.052). Paired exploratory t-tests reported effects on the difference of time [post-pre] between stimulation conditions for LF (P = 0.052), HF (P = 0.052) and LF/HF (P = 0.003). CONCLUSION Anodal tDCS of the motor cortex modulated ANS activity in individuals with SCI independent of gender, type and time of lesion. These changes were in the direction of normalization of ANS parameters, thus confirming our initial hypothesis that an enhancement of cortical excitability by tDCS could at least partially restore some of the dysfunctional activity in the ANS system of subjects with SCI.
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Affiliation(s)
- Fabiana Tenório Gomes da Silva
- Laboratory of Neuromodulation, Center of Clinical Research Learning, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA.,Psychology institute, Department of Neurosciences and behavior, University of São Paulo (USP), São Paulo, Brazil.,Department of Physical Education, Health Sciences Center, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
| | - Rodrigo Alberto Vieira Browne
- Department of Physical Education, Health Sciences Center, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
| | - Camila Bonin Pinto
- Laboratory of Neuromodulation, Center of Clinical Research Learning, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA
| | - Faddi Ghassan Saleh Velez
- Laboratory of Neuromodulation, Center of Clinical Research Learning, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA
| | - Eryvaldo Sócrates Tabosa do Egito
- Department of Pharmacy, Health Sciences Center, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
| | - Jeferson Tafarel Pereira do Rêgo
- Department of Physical Education, Health Sciences Center, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
| | - Marília Rodrigues da Silva
- Department of Physical Education, Health Sciences Center, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
| | - Paulo Moreira Silva Dantas
- Department of Physical Education, Health Sciences Center, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
| | - Felipe Fregni
- Laboratory of Neuromodulation, Center of Clinical Research Learning, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA
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Kapa S, DeSimone CV, Asirvatham SJ. Innervation of the heart: An invisible grid within a black box. Trends Cardiovasc Med 2016; 26:245-57. [PMID: 26254961 PMCID: PMC4706824 DOI: 10.1016/j.tcm.2015.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 06/30/2015] [Accepted: 07/02/2015] [Indexed: 02/07/2023]
Abstract
Autonomic control of cardiovascular function is mediated by a complex interplay between central, peripheral, and innate cardiac components. This interplay is what mediates the normal cardiovascular response to physiologic and pathologic stressors, including blood pressure, cardiac contractile function, and arrhythmias. However, in order to understand how modern therapies directly affecting autonomic function may be harnessed to treat various cardiovascular disease states requires an intimate understanding of anatomic and physiologic features of the innervation of the heart. Thus, in this review, we focus on defining features of the central, peripheral, and cardiac components of cardiac innervation, how each component may contribute to dysregulation of normal cardiac function in various disease states, and how modulation of these components may offer therapeutic options for these diseases.
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Affiliation(s)
- Suraj Kapa
- Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN
| | - Christopher V DeSimone
- Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN
| | - Samuel J Asirvatham
- Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN; Division of Pediatric Cardiology, Department of Pediatrics and Adolescent Medicine, Mayo Clinic College of Medicine, Rochester, MN.
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11
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Kuntze LB, Ferreira-Junior NC, Lagatta DC, Resstel LBM. Ventral hippocampus modulates bradycardic response to peripheral chemoreflex activation in awake rats. Exp Physiol 2016; 101:482-93. [PMID: 26700468 DOI: 10.1113/ep085393] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 12/22/2015] [Indexed: 12/15/2022]
Abstract
NEW FINDINGS What is the central question of this study? Does reversible synaptic inactivation by CoCl2 in the dorsal (DH) or ventral (VH) portions of the hippocampus have a modulatory effect on cardiovascular and respiratory responses evoked by chemoreflex activation in awake rats? What is the main finding and its importance? Using i.v. infusion of KCN to activate the peripheral chemoreflex before and after microinjection of CoCl2 into VH, we showed that the bradycardic response was increased, but not the pressor and tachypnoeic responses even if the tidal volume had been increased. Thus, VH but not DH may be involved in the modulation of the parasympathoexcitatory component of the peripheral chemoreflex. In rats, peripheral chemoreflex activation evokes pressor and bradycardic responses as well as a tachypnoeic response. Studies have shown that limbic structures, such as the hippocampus, can modulate autonomic reflexes. Evidence suggests that the dorsal (DH) and the ventral (VH) portions of the hippocampus are structurally and functionally distinct; therefore, in the present study we tested the hypothesis that local neurotransmission of the DH and VH are involved in the neural pathways of the cardiovascular and ventilatory responses to chemoreflex activation. Thus, the goal of the present study was to compare the chemoreflex responses elicited by i.v. injection of KCN (40 μg per rat) in awake rats before and after DH and VH synaptic transmission was temporarily inhibited by bilateral microinjections of 500 nl of the unspecific synapse blocker, CoCl2 (1 mm). Bilateral inhibition of VH, but not DH, 10 min before KCN infusion was able to enhance the bradycardic response (P < 0.05), with no changes in the typical pressor and tachypnoeic responses evoked by chemoreflex activation (P > 0.05). Furthermore, the tidal volume was significantly increased (P < 0.05) even though no other respiratory parameter had been significantly changed (P > 0.05), suggesting that VH can exert a tonic modulatory action on tidal volume. Therefore, the present study reports, for the first time, that DH neurotransmission did not exert an influence on chemoreflex responses, whereas VH mediates, at least in part, the parasympathoexcitatory component of the peripheral chemoreflex.
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Affiliation(s)
- Luciana Bärg Kuntze
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14090-090, Brazil
| | - Nilson Carlos Ferreira-Junior
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14090-090, Brazil
| | - Davi Campos Lagatta
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14090-090, Brazil
| | - Leonardo Barbosa Moraes Resstel
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14090-090, Brazil
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Sethi A, Callaway CW, Sejdić E, Terhorst L, Skidmore ER. Heart Rate Variability Is Associated with Motor Outcome 3-Months after Stroke. J Stroke Cerebrovasc Dis 2015; 25:129-35. [PMID: 26456199 DOI: 10.1016/j.jstrokecerebrovasdis.2015.09.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/03/2015] [Accepted: 09/09/2015] [Indexed: 10/23/2022] Open
Abstract
OBJECTIVES The primary objective of this paper was to determine whether heart rate variability (HRV) acquired upon admission to inpatient rehabilitation is associated with motor outcome 3 months after stroke. The secondary objective of this paper was to determine whether HRV shows a strong association with the motor outcome 3 months after stroke in individuals with severe initial motor impairments. METHODS We recruited 13 patients with acute stroke from an acute inpatient rehabilitation hospital. A Holter monitor was placed upon admission and Fugl-Meyer Upper Extremity and Lower Extremity Subscales were used to assess the movement of the affected upper and lower extremities 3 months after admission. The standard deviation of R-R intervals was used to quantify HRV. RESULTS A Spearman rank correlation revealed a strong positive and significant correlation between HRV upon admission and movement of the affected upper extremity (r = .70, P = .01) and affected lower extremity (r = .60, P = .03) at 3 months. For patients with severe initial motor impairments, HRV showed a strong positive association with the movement of the affected upper (r = .61, P = .04) and lower (r = .70, P = .04) extremities at 3 months. CONCLUSION HRV is strongly associated with motor outcome after stroke and provides a promising marker to explore the mechanisms associated with motor recovery after stroke.
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Affiliation(s)
- Amit Sethi
- Department of Occupational Therapy, University of Pittsburgh, Pittsburgh, Pennsylvania.
| | - Clifton W Callaway
- Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Ervin Sejdić
- Department of Electrical Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Lauren Terhorst
- Department of Occupational Therapy, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Elizabeth R Skidmore
- Department of Occupational Therapy, University of Pittsburgh, Pittsburgh, Pennsylvania
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Ryan JP, Sheu LK, Verstynen TD, Onyewuenyi IC, Gianaros PJ. Cerebral blood flow links insulin resistance and baroreflex sensitivity. PLoS One 2013; 8:e83288. [PMID: 24358272 PMCID: PMC3865223 DOI: 10.1371/journal.pone.0083288] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 11/12/2013] [Indexed: 12/02/2022] Open
Abstract
Insulin resistance confers risk for diabetes mellitus and associates with a reduced capacity of the arterial baroreflex to regulate blood pressure. Importantly, several brain regions that comprise the central autonomic network, which controls the baroreflex, are also sensitive to the neuromodulatory effects of insulin. However, it is unknown whether peripheral insulin resistance relates to activity within central autonomic network regions, which may in turn relate to reduced baroreflex regulation. Accordingly, we tested whether resting cerebral blood flow within central autonomic regions statistically mediated the relationship between insulin resistance and an indirect indicator of baroreflex regulation; namely, baroreflex sensitivity. Subjects were 92 community-dwelling adults free of confounding medical illnesses (48 men, 30-50 years old) who completed protocols to assess fasting insulin and glucose levels, resting baroreflex sensitivity, and resting cerebral blood flow. Baroreflex sensitivity was quantified by measuring the magnitude of spontaneous and sequential associations between beat-by-beat systolic blood pressure and heart rate changes. Individuals with greater insulin resistance, as measured by the homeostatic model assessment, exhibited reduced baroreflex sensitivity (b = -0.16, p < .05). Moreover, the relationship between insulin resistance and baroreflex sensitivity was statistically mediated by cerebral blood flow in central autonomic regions, including the insula and cingulate cortex (mediation coefficients < -0.06, p-values < .01). Activity within the central autonomic network may link insulin resistance to reduced baroreflex sensitivity. Our observations may help to characterize the neural pathways by which insulin resistance, and possibly diabetes mellitus, relates to adverse cardiovascular outcomes.
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Affiliation(s)
- John P. Ryan
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Lei K. Sheu
- Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Timothy D. Verstynen
- Department of Psychology, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Ikechukwu C. Onyewuenyi
- Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Peter J. Gianaros
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
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14
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Clancy JA, Johnson R, Raw R, Deuchars SA, Deuchars J. Anodal transcranial direct current stimulation (tDCS) over the motor cortex increases sympathetic nerve activity. Brain Stimul 2013; 7:97-104. [PMID: 24080439 DOI: 10.1016/j.brs.2013.08.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 08/19/2013] [Accepted: 08/23/2013] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Transcranial direct current stimulation (tDCS) is currently being investigated as a non-invasive neuromodulation therapy for a range of conditions including stroke rehabilitation. tDCS affects not only the area underlying the electrodes but also other areas of the cortex and subcortical structures. This could lead to unintended alteration in brain functions such as autonomic control. OBJECTIVE We investigated the potential effects of tDCS on cardiovascular autonomic function in healthy volunteers. METHODS Anodal (n = 14) or cathodal (n = 8) tDCS at 1 mA was applied over the primary motor cortex with the second electrode placed on the contralateral supraorbital region. Subjects visited the department twice and received active or sham tDCS for 15 min. Heart rate, blood pressure and respiration were recorded at baseline, during tDCS and after stimulation. Heart rate variability (HRV) was calculated using spectral analysis of beat-to-beat intervals derived from ECG data. Microneurography was also used to record muscle sympathetic nerve activity (MSNA; n = 5). RESULTS Anodal tDCS caused a significant shift in HRV toward sympathetic predominance (P = 0.017), whereas there was no significant change in the cathodal or sham groups. Microneurography results also showed a significant increase in MSNA during anodal tDCS that continued post-stimulation. CONCLUSIONS Anodal tDCS of the motor cortex shifts autonomic nervous system balance toward sympathetic dominance due at least in part to an increase in sympathetic output. These results suggest further investigation is warranted on tDCS use in patient groups with potential autonomic dysfunction, such as stroke patients.
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Affiliation(s)
- Jennifer A Clancy
- School of Biomedical Sciences, University of Leeds, Garstang Building, Leeds LS2 9JT, UK
| | - Robyn Johnson
- Institute of Psychological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Rachael Raw
- Institute of Psychological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Susan A Deuchars
- School of Biomedical Sciences, University of Leeds, Garstang Building, Leeds LS2 9JT, UK
| | - Jim Deuchars
- School of Biomedical Sciences, University of Leeds, Garstang Building, Leeds LS2 9JT, UK.
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15
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Bowman BR, Kumar NN, Hassan SF, McMullan S, Goodchild AK. Brain sources of inhibitory input to the rat rostral ventrolateral medulla. J Comp Neurol 2013; 521:213-32. [PMID: 22740031 DOI: 10.1002/cne.23175] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 05/02/2012] [Accepted: 06/20/2012] [Indexed: 12/19/2022]
Abstract
The rostral ventrolateral medulla (RVLM) contains neurons critical for cardiovascular, respiratory, metabolic, and motor control. The activity of these neurons is controlled by inputs from multiple identified brain regions; however, the neurochemistry of these inputs is largely unknown. Gamma-aminobutyric acid (GABA) and enkephalin tonically inhibit neurons within the RVLM. The aim of this study was to identify all brain regions that provide GABAergic or enkephalinergic input to the rat RVLM. Neurons immunoreactive for cholera toxin B (CTB-ir), retrogradely transported from the RVLM, were assessed for expression of glutamic acid decarboxylase (GAD67) or preproenkephalin (PPE) mRNA using in situ hybridization. GAD67 mRNA was expressed in CTB-ir neurons in the following regions: the nucleus of the solitary tract (NTS, 6% of CTB-ir neurons), area postrema (AP, 8%), caudal ventrolateral medulla (17%), midline raphe (40%), ventrolateral periaqueductal gray (VLPAG, 15%), lateral hypothalamic area (LHA, 25%), central nucleus of the amygdala (CeA, 77%), sublenticular extended amygdala (SLEA, 86%), interstitial nucleus of the posterior limb of the anterior commissure (IPAC, 56%), bed nucleus of the stria terminals (BNST, 59%), and medial preoptic area (MPA, 53%). PPE mRNA was expressed in CTB-ir neurons in the following regions: the NTS (14% of CTB-ir neurons), midline raphe (26%), LHA (22%), zona incerta (ZI, 15%), CeA (5%), paraventricular nucleus (PVN, 13%), SLEA (66%), and MPA (26%). Thus, limited brain regions contribute GABAergic and/or enkephalinergic input to the RVLM. Multiple neurochemically distinct pathways originate from these brain regions projecting to the RVLM.
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Affiliation(s)
- Belinda R Bowman
- Australian School of Advanced Medicine, Macquarie University, 2109, NSW Australia
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16
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Granjeiro ÉM, Gomes FV, Alves FH, Crestani CC, Corrêa FM, Resstel LB. Bed nucleus of the stria terminalis and the cardiovascular responses to chemoreflex activation. Auton Neurosci 2012; 167:21-6. [DOI: 10.1016/j.autneu.2011.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 11/20/2011] [Accepted: 11/25/2011] [Indexed: 01/06/2023]
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17
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Riganello F, Garbarino S, Sannita WG. Heart Rate Variability, Homeostasis, and Brain Function. J PSYCHOPHYSIOL 2012. [DOI: 10.1027/0269-8803/a000080] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Measures of heart rate variability (HRV) are major indices of the sympathovagal balance in cardiovascular research. These measures are thought to reflect complex patterns of brain activation as well and HRV is now emerging as a descriptor thought to provide information on the nervous system organization of homeostatic responses in accordance with the situational requirements. Current models of integration equate HRV to the affective states as parallel outputs of the central autonomic network, with HRV reflecting its organization of affective, physiological, “cognitive,” and behavioral elements into a homeostatic response. Clinical application is in the study of patients with psychiatric disorders, traumatic brain injury, impaired emotion-specific processing, personality, and communication disorders. HRV responses to highly emotional sensory inputs have been identified in subjects in vegetative state and in healthy or brain injured subjects processing complex sensory stimuli. In this respect, HRV measurements can provide additional information on the brain functional setup in the severely brain damaged and would provide researchers with a suitable approach in the absence of conscious behavior or whenever complex experimental conditions and data collection are impracticable, as it is the case, for example, in intensive care units.
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Affiliation(s)
- Francesco Riganello
- S. Anna Institute and RAN – Research in Advanced Neurorehabilitation, Crotone, Italy
| | - Sergio Garbarino
- Department of Neuroscience, Ophthalmology and Genetics, University of Genova, Italy
| | - Walter G. Sannita
- Department of Neuroscience, Ophthalmology and Genetics, University of Genova, Italy
- Department of Psychiatry, State University of New York, Stony Brook, NY, USA
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18
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Operant reflexes and expression of the c-fos gene in the amygdalar nuclei and insular cortex of rats. NEUROPHYSIOLOGY+ 2011. [DOI: 10.1007/s11062-011-9218-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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19
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Ally A, Maher TJ. Transient middle cerebral artery occlusion and reperfusion alters inducible NOS expression within the ventrolateral medulla and modulates cardiovascular function during static exercise. Can J Physiol Pharmacol 2011; 89:639-46. [DOI: 10.1139/y11-064] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A major cause of stroke is cerebral ischemia in regions supplied by the middle cerebral artery (MCA). In this study, we hypothesized that compromised cardiovascular function during static exercise may involve altered expression of inducible NOS (iNOS) protein within the rostral ventrolateral medulla (RVLM) and caudal ventrolateral medulla (CVLM). We compared cardiovascular responses and iNOS protein expression within the left and right sides of both RVLM and CVLM in sham-operated rats and in rats with a 90 min left-sided MCA occlusion (MCAO) followed by 24 h of reperfusion. Increases in blood pressure during a static muscle contraction were attenuated in MCAO rats compared with sham-operated rats. Also, iNOS expression within the left RVLM was augmented compared with the right RVLM in MCAO rats and compared with both RVLM quadrants in sham-operated rats. In contrast, compared with sham-operated rats and the right CVLM of MCAO rats, iNOS expression was attenuated in the left CVLM in left-sided MCAO rats. These data suggest that the attenuation of pressor responses during static exercise in MCAO rats involves overexpression of iNOS within the ipsilateral RVLM and attenuation in iNOS within the ipsilateral CVLM. Differential expression of iNOS within the medulla plays a role in mediating cardiovascular responses during static exercise following stroke.
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Affiliation(s)
- Ahmmed Ally
- Department of Pharmaceutical Sciences, South College School of Pharmacy, 400 Goody’s Lane, Knoxville, TN 37922, USA
| | - Timothy J. Maher
- Department of Pharmaceutical Sciences, Massachusetts College of Pharmacy and Health Sciences, Boston, MA 02115, USA
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20
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Granjeiro ÉM, Scopinho AA, Corrêa FMA, Resstel LBM. Prelimbic but not infralimbic cortex is involved in the pressor response to chemoreflex activation in awake rats. Exp Physiol 2011; 96:518-27. [DOI: 10.1113/expphysiol.2011.057596] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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21
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Vlasenko OV, Buzyka TV, Maiskii VA, Pilyavskii AI, Maznychenko AV. Activation of Neurons of the Medullary Centers of the Autonomic Nervous System Related to Motivated Operant Movements Realized by Rats. NEUROPHYSIOLOGY+ 2011. [DOI: 10.1007/s11062-011-9166-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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22
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Foster PS, Drago V, Harrison DW, Skidmore F, Crucian GP, Heilman KM. Influence of left versus right hemibody onset Parkinson's disease on cardiovascular control. Laterality 2010; 16:164-73. [PMID: 20306353 DOI: 10.1080/13576500903483507] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Whereas the left hemisphere is involved in regulating the parasympathetic nervous system, the right hemisphere regulates the sympathetic. Given the asymmetrical onset of motor symptoms and neuropathology in PD, differences in cardiovascular functions might be expected between PD patients with left hemibody onset (LHO) versus right hemibody onset (RHO). A total of 66 PD patients served as participants, including 31 LHO patients and 35 RHO PD patients. All participants had their resting heart rate (HR) and blood pressure (BP) recorded. Although the LHO group had lower systolic BP, it had higher resting HR than did the RHO group. The reason for this dissociation is not known but might be related to asymmetrical vagus nerve control of the heart (SA node). Future researchers might want to use additional indices of cardiovascular functioning that are more precise measures of parasympathetic and sympathetic functioning, as well as learn the influence of dopaminergic medications.
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Affiliation(s)
- Paul S Foster
- Middle Tennessee State University, Psychology Department, Murfreesboro, TN 37132, USA.
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23
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Cogiamanian F, Brunoni A, Boggio P, Fregni F, Ciocca M, Priori A. Non-invasive brain stimulation for the management of arterial hypertension. Med Hypotheses 2010; 74:332-6. [DOI: 10.1016/j.mehy.2009.08.037] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Accepted: 08/23/2009] [Indexed: 11/15/2022]
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24
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Spectral Analysis of Heart Rate Variability During Asleep-Awake Craniotomy for Tumor Resection. J Neurosurg Anesthesiol 2009; 21:242-7. [DOI: 10.1097/ana.0b013e31819b61df] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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25
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Sequeira H, Hot P, Silvert L, Delplanque S. Electrical autonomic correlates of emotion. Int J Psychophysiol 2009; 71:50-6. [DOI: 10.1016/j.ijpsycho.2008.07.009] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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26
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Buller KM, Wixey JA, Pathipati P, Carty M, Colditz PB, Williams CE, Scheepens A. Selective losses of brainstem catecholamine neurons after hypoxia-ischemia in the immature rat pup. Pediatr Res 2008; 63:364-9. [PMID: 18356740 DOI: 10.1203/pdr.0b013e3181659774] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Hypoxic-ischemic (HI) injury in the preterm neonate incurs numerous functional deficits, however little is known about the neurochemically-defined brain nuclei that may underpin them. Key candidates are the brainstem catecholamine neurons. Using an immature animal model, the postnatal day (P)-3 (P3) rat pup, we investigated the effects of HI on brainstem catecholamine neurons in the locus coeruleus, nucleus tractus solitarius (NTS), and ventrolateral medulla (VLM). On P21, we found that prior P3 HI significantly reduced numbers of catecholaminergic neurons in the locus coeruleus, NTS, and VLM. Only locus coeruleus A6, NTS A2, and VLM A1 noradrenergic neurons, but not NTS C2 and VLM C1 adrenergic neurons, were lost. There was also an associated reduction in dopamine-beta-hydroxylase-positive immunolabeling in the forebrain. These findings suggest neonatal HI can affect specific neurochemically-defined neuronal populations in the brainstem and that noradrenergic neurons are particularly vulnerable to HI injury.
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Affiliation(s)
- Kathryn M Buller
- Perinatal Research Centre, University of Queensland, Queensland 4029, Australia.
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27
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Ally A, Maher TJ. Endothelial NOS expression within the ventrolateral medulla can affect cardiovascular function during static exercise in stroked rats. Brain Res 2007; 1196:33-40. [PMID: 18234158 DOI: 10.1016/j.brainres.2007.12.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 12/03/2007] [Accepted: 12/16/2007] [Indexed: 11/26/2022]
Abstract
Temporary occlusion of the middle cerebral artery (MCA) causing damage to brain tissue occurs in the majority of human stroke victims. Reflex cardiovascular responses during static exercise were attenuated following transient MCA occlusion (MCAO) and reperfusion, mediated via alteration of the neuronal nitric oxide synthase (nNOS) protein isoform within the rostral (RVLM) and caudal (CVLM) ventrolateral medulla (Ally, A., Nauli, S.M., Maher, T.J. 2005. Molecular changes in nNOS protein expression within the ventrolateral medulla following transient focal ischemia affect cardiovascular functions. Brain Res. [1055, 73-82]. We hypothesized that the endothelial NOS (eNOS) isoform within the RVLM and CVLM might also play a role in integrating cardiovascular function. Thus, we compared cardiovascular responses to static muscle contraction and eNOS expression within the four quadrants, i.e., left and right sides of both RVLM and CVLM in sham operated rats and in rats with a temporary 90-minute one-sided MCAO followed by 24 hour reperfusion. Increases in arterial pressure during a muscle contraction were attenuated in MCAO rats when compared to sham rats. Left-sided MCAO significantly decreased the expression of eNOS in the ipsilateral side but not contralateral RVLM, and to both RVLM quadrants in sham-operated rats. In contrast, compared to sham rats and the right CVLM quadrant of MCAO rats, eNOS expression was significantly increased in the left ipsilateral CVLM quadrant in left-sided MCAO rats. These data suggest that attenuation of cardiovascular responses during muscle contraction in MCAO rats may be partly due to a reduction in eNOS expression within the ipsilateral RVLM and an overexpression of eNOS within the ipsilateral CVLM. Results demonstrate that the eNOS protein within the medulla may play a significant role in mediating cardiovascular responses during static exercise in pathophysiological conditions, such as stroke.
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Affiliation(s)
- Ahmmed Ally
- Department of Pharmaceutical Sciences, Massachusetts College of Pharmacy and Health Sciences, 179 Longwood Avenue, Boston, MA 02115, USA.
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28
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Pan B, Kim EJ, Schramm LP. Increased close appositions between corticospinal tract axons and spinal sympathetic neurons after spinal cord injury in rats. J Neurotrauma 2006; 22:1399-410. [PMID: 16379578 DOI: 10.1089/neu.2005.22.1399] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Treatments for spinal cord injury may promote new spinal cord synapses. However, the potential for new synapses between descending somatomotor and spinal sympathetic neurons has not been investigated. We studied rats with intact spinal cords and rats after a chronic, bilateral, dorsal spinal hemisection. We identified sympathetically related spinal neurons by transynaptic, retrograde transport of renally injected pseudorabies virus. We counted retrogradely labeled sympathetic preganglionic neurons (SPN) and putative sympathetic interneurons (IN) that, under light microscopy, appeared closely apposed by anterogradely labeled axons of the corticospinal tract (CST) and by axons descending from the well-established sympathetic regulatory region in the rostral ventrolateral medulla (RVLM). Spinal sympathetic neurons that were closely apposed by CST axons were significantly more numerous in lesioned rats than in unlesioned rats. CST axons closely apposed 5.4% of SPN and 10.3% of IN in rats with intact spinal cords, and 38.0% of SPN and 37.3% of IN in rats with chronically lesioned spinal cords. Further, CST appositions in SCI rats consisted of many more varicosities than those in uninjured rats. SPN and IN closely apposed by axons from the RVLM were not more numerous in lesioned rats. However, RVLM axons apposed many more SPN than IN in both control and lesioned rats. Therefore, RVLM sympathoexcitation may be mediated largely by direct synapses on SPN. Although we have not determined the functional significance of close appositions between the CST and spinal sympathetic neurons, we suggest that future studies of spinal cord repair and regeneration include an evaluation of potential, new, somatic-autonomic interactions.
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Affiliation(s)
- Baohan Pan
- Department of Biomedical Engineering, The Johns Hopkins School of Medicine, 605 Traylor Building, 720 Rutland Avenue, Baltimore, MD 21205, USA.
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29
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Hou Z, Miao Y, Gao L, Pan H, Zhu S. Ghrelin-containing neuron in cerebral cortex and hypothalamus linked with the DVC of brainstem in rat. ACTA ACUST UNITED AC 2006; 134:126-31. [PMID: 16600402 DOI: 10.1016/j.regpep.2006.02.005] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 10/13/2005] [Accepted: 02/17/2006] [Indexed: 11/17/2022]
Abstract
Ghrelin is a newly discovered brain-gut peptide and an endogenous ligand for growth hormone secretagogues receptor (GHS-R). Ghrelin and GHS-R present extensively in central and peripheral tissues such as stomach, brain and other organs of rodent and human, which suggest it has multiple biological effects. It has been reported that ghrelin has significant role in the regulation of energy homeostasis, food intake and appetite. The organization of central circuitry appears to play an important role in integrating orexigenic effects of ghrelin, but the detail is not fully clear. In this study, we examined the expression of ghrelin, ghrelin mRNA and GHS-R mRNA in cerebrum and brainstem by RT-PCR and immunofluorescence histochemistry, and analyzed the connection among the cerebral cortex, hypothalamus, dorsal vagal complex (DVC). The results showed that the positive staining of ghrelin was found on the pyramidal neuron of layer V in the sensorimotor area of cerebral cortex, cingulate gyrus, as well as in the neuron of lateral hypothalamus (LH), PVN and ARC. The expression of ghrelin mRNA and GHS-R mRNA were also found in the sensorimotor cortex and hypothalamus by method of RT-PCR. The GHS-R mRNA was also found in the DVC of medulla oblongata. Other finding is that the FG/ghrelin dual labeled neurons were found in LH of hypothalamus (not in cortex). The ghrelin-containing neuron in the LH projects its axon to the DVC with the method of retrograde tracing. In conclusion, the ghrelin neurons are located not only in hypothalamus (LH, PVN, ARC), but also in the cortex (sensorimotor area, cingular gyrus), and the fibers of ghrelin neurons in hypothalamus projected directly to the DVC. It suggests that ghrelin plays its role from hypothalamus to brainstem as a neurotransmitter or neuromodulator to regulate function of vagal nuclei in brainstem.
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Affiliation(s)
- Zhongchi Hou
- Department of Physiology and Pathophysiology, Peking University Health Science Center, 38 Xueyuan Road, Beijing 100083, PR China
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30
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McDougall SJ, Widdop RE, Lawrence AJ. Central autonomic integration of psychological stressors: Focus on cardiovascular modulation. Auton Neurosci 2005; 123:1-11. [PMID: 16289941 DOI: 10.1016/j.autneu.2005.09.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Revised: 07/14/2005] [Accepted: 09/28/2005] [Indexed: 02/04/2023]
Abstract
During stress the sympathoadrenal system and the hypothalamo-pituitary-adrenal axis act in a coordinated manner to force changes within an animal's current physiological and behavioral state. Such changes have been described as 'fight flight' or stress responses. The central nervous system may generate a stress response by different neural circuits, this being dependent upon the type of stressor presented. For instance, the central control of the autonomic function during physical stress would seem to be based on existing homeostatic mechanisms. In contrast, with exposure to psychological stress the means by which autonomic outflow is regulated has not been fully established. This review discusses recent observations of autonomic flow, cardiovascular components in particular, during psychological stress and the possible implications these may have for our understanding of the central nervous system. In addition, an update of recent findings concerning several regions thought to be important to the regulation of autonomic function during psychological stress exposure is provided.
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Affiliation(s)
- Stuart J McDougall
- Howard Florey Institute, University of Melbourne, Parkville, Victoria, Australia
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31
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Ally A, Nauli SM, Maher TJ. Molecular changes in nNOS protein expression within the ventrolateral medulla following transient focal ischemia affect cardiovascular functions. Brain Res 2005; 1055:73-82. [PMID: 16084499 DOI: 10.1016/j.brainres.2005.06.087] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2005] [Revised: 06/28/2005] [Accepted: 06/29/2005] [Indexed: 10/25/2022]
Abstract
The majority of human strokes involve an occlusion of the middle cerebral artery and subsequent damage to the brain tissues it perfuses. We have previously reported that reflex cardiovascular changes during a static muscle contraction are attenuated following transient middle cerebral artery occlusion (MCAO) and reperfusion [A. Ally, S.M. Nauli, T.J. Maher, Cardiovascular responses and neurotransmission in the ventrolateral medulla during skeletal muscle contraction following transient middle cerebral artery occlusion and reperfusion, Brain Res. 952 (2002) 176-187]. We hypothesized that the attenuation is a result of altered expression of neuronal nitric oxide synthase (nNOS) within the rostral (RVLM) and caudal ventrolateral medulla (CVLM). In this study, we have compared cardiovascular responses and nNOS protein expression within the four quadrants, i.e., left and right sides of both RVLM and CVLM in sham-operated rats (n = 10) and in rats with a temporary 90-min left-sided MCAO followed by 24 h reperfusion (n = 10). Increases in mean arterial pressure during a static muscle contraction were significantly attenuated in MCAO rats when compared to sham rats. The transient ischemia reduced nNOS expression within the ipsilateral RVLM quadrant compared to the contralateral RVLM or RVLM quadrants of control rats. In contrast, compared to sham rats and the right CVLM quadrant of MCAO rats, nNOS expression was significantly augmented in the ipsilateral CVLM in left-sided MCAO rats. These data suggest that the attenuation of cardiovascular responses during static muscle contraction in MCAO rats is partly due to a reduction in nNOS expression within the ipsilateral RVLM and an overexpression of nNOS abundance within the ipsilateral CVLM. Results demonstrate that nNOS expression within the medulla plays a significant role in mediating cardiovascular responses during static exercise in intact and pathophysiological conditions.
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Affiliation(s)
- Ahmmed Ally
- Department of Pharmaceutical Sciences, Lloyd L. Gregory School of Pharmacy, Palm Beach Atlantic University, 901 South Flagler Drive, West Palm Beach, FL 33416, USA.
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32
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Resstel LBM, Corrêa FMA. Pressor and tachycardic responses evoked by microinjections of l-glutamate into the medial prefrontal cortex of unanaesthetized rats. Eur J Neurosci 2005; 21:2513-20. [PMID: 15932608 DOI: 10.1111/j.1460-9568.2005.04078.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ventral medial prefrontal cortex (vMPFC) is involved in central cardiovascular control. In the present study, we studied the cardiovascular effects of injections of L-glutamate into the vMPFC of unanaesthetized rats and the mechanisms of these effects. Male Wistar rats were used and L-glutamate was microinjected in the vMPFC in a final volume of 200 nL. Microinjections of L-glutamate (9, 27, 81, 150 or 300 nmol) caused long-lasting, dose-related pressor and tachycardic responses in unanaesthetized rats. No differences were observed among cardiovascular responses when L-glutamate was injected into the three sub-areas that comprise the vMPFC, namely the prelimbic, the infralimbic and the dorsal peduncular cortices. No responses were observed when the dose of 81 nmol of L-glutamate was microinjected into surrounding structures such as the cingulate cortex area 1, the corpus callosum and the tenia tecta, indicating a predominant action on the vMPFC. The cardiovascular response to L-glutamate into the vMPFC was blocked by intravenous pretreatment with the ganglion blocker pentolinium (10 mg/kg, i.v.) or the beta1-adrenoceptor antagonist atenolol (1.5 mg/kg, i.v.), supporting the involvement of the cardiac sympathetic nervous system in the response to L-glutamate. Pretreatment with the muscarinic antagonist homatropine methyl bromide (1 mg/kg, i.v.) reduced the latency to the onset of the pressor and tachycardic responses to L-glutamate injected into the vMPFC without significant effects on response duration or maximum effect. We conclude that stimulation of the vMPFC with L-glutamate caused pressor and tachycardic responses in unanaesthetized rats, responses which were dependent on cardiac sympathetic nerve activation and were potentiated by blockade of peripheral muscarinic receptors.
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Affiliation(s)
- L B M Resstel
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil
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Bell HJ, Feenstra W, Duffin J. The initial phase of exercise hyperpnoea in humans is depressed during a cognitive task. Exp Physiol 2005; 90:357-65. [PMID: 15665147 DOI: 10.1113/expphysiol.2004.028779] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Increased wakefulness is known to suppress the initial ventilatory response to passive movement and the steady-state ventilatory response to exercise. However, the effect of increased wakefulness upon the integrated ventilatory response at the onset of exercise is not known. We hypothesized that increasing wakefulness via a cognitive task would attenuate the initial ventilatory response to exercise, and so we examined the response to active leg extensions under two conditions: with and without concurrently solving a puzzle. At rest before exercise, subjects demonstrated greater minute ventilation while solving a puzzle (mean +/- S.E.M., 12.38 +/- 0.55 versus 10.12 +/- 0.51 l min(-1), P < 0.001), due to a higher mean breathing frequency (mean +/- S.E.M., 17.1 +/- 0.93 versus 13.6 +/- 0.59 breaths min(-1), P < 0.001). At the start of exercise, subjects did not increase their ventilation significantly while solving the puzzle (P = 0.170), but did by a mean +/-s.e.m. of 6.16 +/- 1.12 l min(-1) (P < 0.001) when not puzzle solving. The ventilation achieved at the start of exercise in absolute terms was also lower while solving the puzzle (14.6 +/- 1.1 versus 16.3 +/- 1.3 l min(-1), P = 0.047). Despite differences in the rapid ventilatory response to exercise between conditions, the steady-state responses were not different. We conclude that the performance of a cognitive task decreases the initial phase of exercise hyperpnoea, and suggest that this might occur because of either a competitive interaction between drives to breathe or a behavioural distraction from the 'task' of exercise.
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Affiliation(s)
- Harold J Bell
- Department of Physiology, Medical Sciences Building, 1 King's College Circle, University of Toronto, Toronto, Ontario, Canada M5S 1A8
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Serova LI, Maharjan S, Sabban EL. Estrogen modifies stress response of catecholamine biosynthetic enzyme genes and cardiovascular system in ovariectomized female rats. Neuroscience 2005; 132:249-59. [PMID: 15802180 DOI: 10.1016/j.neuroscience.2004.12.040] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2004] [Indexed: 12/18/2022]
Abstract
Estrogen is likely involved in the gender specific differences in coping with stress. Activation of catecholamine (CA) biosynthetic enzyme gene expression in central and peripheral CA systems plays a key role in response to stress and in regulation of the cardiovascular system. Here we examined whether estradiol can modulate response of hypothalamic-pituitary-adrenal axis (HPA), gene expression of enzymes related to CA biosynthesis in several noradrenergic locations, tetrahydrobiopterin (BH4) concentration and blood pressure (BP) in response to immobilization stress (IMO) of ovariectomized female rats. Rats were injected with 25 mug/kg estradiol benzoate (EB) or sesame oil once daily for 16 days and subsequently exposed to two hours of IMO. The IMO triggered elevation in plasma ACTH was lessened in EB-pretreated animals. However, estradiol did not alter the IMO-elicited rise of tyrosine hydroxylase mRNA levels in adrenal medulla (AM) and in the nucleus of solitary track (NTS) compared with controls. The response of GTP cyclohydrolase I (GTPCH) mRNA in AM to IMO was also similar in both groups. Several responses to IMO in EB-treated rats were reversed. Instead of IMO-elicited elevation in dopamine beta-hydroxylase mRNA levels in the locus coeruleus, GTPCH mRNA and BH4 levels in the NTS, they were reduced by IMO. In a parallel experiment, BP was monitored during restraint stress. The elevation of BP in response to single or repeated restraint stress was sustained during 2 h in controls and reduced after 70 min stress in EB treated rats. One month after withdrawal of EB treatment, the BP response to restraint was similar to that of rats which never received EB. The results demonstrate that estrogen can modulate responses to stress affecting HPA axis, CA biosynthesis, in central and peripheral noradrenergic systems, and BP.
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Affiliation(s)
- L I Serova
- Department of Biochemistry and Molecular Biology, Basic Science Building, New York Medical College, Valhalla, NY 10595, USA.
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Bell HJ, Duffin J. Respiratory response to passive limb movement is suppressed by a cognitive task. J Appl Physiol (1985) 2004; 97:2112-20. [PMID: 15273238 DOI: 10.1152/japplphysiol.00302.2004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Feedback from muscles stimulates ventilation at the onset of passive movement. We hypothesized that central neural activity via a cognitive task source would interact with afferent feedback, and we tested this hypothesis by examining the fast changes in ventilation at the transition from rest to passive leg movement, under two conditions: 1) no task and 2) solving a computer-based puzzle. Resting breathing was greater in condition 2 than in condition 1, evidenced by an increase in mean +/- SE breathing frequency (18.2 +/- 1.1 vs. 15.0 +/- 1.2 breaths/min, P = 0.004) and ventilation (10.93 +/- 1.16 vs. 9.11 +/- 1.17 l/min, P < 0.001). In condition 1, the onset of passive movement produced a fast increase in mean +/- SE breathing frequency (change of 2.9 +/- 0.4 breaths/min, P < 0.001), tidal volume (change of 233 +/- 95 ml, P < 0.001), and ventilation (change of 6.00 +/- 1.76 l/min, P < 0.001). However, in condition 2, the onset of passive movement only produced a fast increase in mean +/- SE breathing frequency (change of 1.3 +/- 0.4 breaths/min, P = 0.045), significantly smaller than in condition 1 (P = 0.007). These findings provide evidence for an interaction between central neural cognitive activity and the afferent feedback mechanism, and we conclude that the performance of a cognitive task suppresses the respiratory response to passive movement.
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Affiliation(s)
- Harold J Bell
- Dept. of Physiology, University of Toronto, 1 King's College Circle, Toronto, ON, Canada M5S 1A8
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Dampney RAL, Horiuchi J. Functional organisation of central cardiovascular pathways: studies using c-fos gene expression. Prog Neurobiol 2003; 71:359-84. [PMID: 14757116 DOI: 10.1016/j.pneurobio.2003.11.001] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Until about 10 years ago, knowledge of the functional organisation of the central pathways that subserve cardiovascular responses to homeostatic challenges and other stressors was based almost entirely on studies in anaesthetised animals. More recently, however, many studies have used the method of the expression of immediate early genes, particularly the c-fos gene, to identify populations of central neurons that are activated by such challenges in conscious animals. In this review we first consider the advantages and limitations of this method. Then, we discuss how the application of the method of immediate early gene expression, when used alone or in combination with other methods, has contributed to our understanding of the central mechanisms that regulate the autonomic and neuroendocrine response to various cardiovascular challenges (e.g., hypotension, hypoxia, hypovolemia, and other stressors) as they operate in the conscious state. In general, the results of studies of central cardiovascular pathways using immediate early gene expression are consistent with previous studies in anaesthetised animals, but in addition have revealed other previously unrecognised pathways that also contribute to cardiovascular regulation. Finally, we briefly consider recent evidence indicating that immediate early gene expression can modify the functional properties of central cardiovascular neurons, and the possible significance of this in producing long-term changes in the regulation of the cardiovascular system both in normal and pathological conditions.
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Affiliation(s)
- R A L Dampney
- Department of Physiology and Institute for Biomedical Research, University of Sydney, Sydney, NSW 2006, Australia.
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Ally A, Nauli SM, Maher TJ. Cardiovascular responses and neurotransmission in the ventrolateral medulla during skeletal muscle contraction following transient middle cerebral artery occlusion and reperfusion. Brain Res 2002; 952:176-87. [PMID: 12376178 DOI: 10.1016/s0006-8993(02)03182-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We hypothesized that static skeletal muscle contraction-induced systemic cardiovascular responses, and central glutamate/GABA release in rostral (RVLM) and caudal ventrolateral medulla (CVLM), would be modulated by cerebral ischemia. In sham-operated rats, a 2-min tibial nerve stimulation induced static contraction of the triceps surae, evoked pressor responses, increased glutamate in both the RVLM and CVLM, decreased GABA in the CVLM, and increased GABA in the RVLM. In rats with a temporary 90-min left middle cerebral artery occlusion (MCAO) followed by 24 h reperfusion, pressor responses during muscle contractions were attenuated, as were glutamate within the left RVLM and left CVLM. Glutamate within the right RVLM and right CVLM were unaltered and similar to those in sham rats. In contrast, GABA increases during muscle contractions were enhanced in the left RVLM and CVLM but changes within the right CVLM and RVLM were similar to those in sham rats. These results indicate that unilateral ischemia increases ipsilateral GABA/glutamate ratios during muscle contraction in the RVLM. In contrast, opposite changes in ipsilateral glutamate and GABA release within the RVLM and CVLM were observed following a 90-min right-sided MCAO followed by 24 h reperfusion. However, cardiovascular responses during muscle contraction were depressed following such an ischemic brain injury. These data suggest that transient ischemic brain injury attenuates cardiovascular responses to static exercise via modulating neurotransmission within the ventrolateral medulla.
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Affiliation(s)
- Ahmmed Ally
- Department of Physiology, Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
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