Differential Control of Central Cardiorespiratory Interactions by Hypercapnia and the Effect of Prenatal Nicotine

Huang, Zheng Gui; Griffioen, Kathleen J.; Wang, Xin; Dergacheva, Olga; Kamendi, Harriet; Gorini, Christopher; Bouairi, Evguenia; Mendelowitz, David

doi:10.1523/jneurosci.4221-05.2006

Cited by 30 publications

(22 citation statements)

References 49 publications

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“…In the presence of ketanserin (1 μM) applications of α-Me-5-HT (1 μM) failed to significantly change the fictive inspiratory burst frequency (2.4 ± 0.3 versus 2.6 ± 0.2 bursts/min (single application; n = 10), and 2.4 ± 0.3 versus 1.9 ± 0.3 bursts/min (multiple applications; n = 10)), Fig. 1, D. Consistent with previous reports (Neff et al, 2004;Huang et al, 2006) the frequency of GABAergic IPSCs increased during fictive inspiratory bursts (Fig. 2, A; Fig.…”

Section: Resultssupporting

confidence: 90%

5-HT2 receptor subtypes mediate different long-term changes in GABAergic activity to parasympathetic cardiac vagal neurons in the nucleus ambiguus

et al. 2007

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Serotonin (5-HT), and in particular 5-HT 2 receptors, play an important role in cardiorespiratory function within the brainstem. In addition, abnormalities in the 5-HT system have been implicated in many cardiorespiratory disorders, including sudden infant death syndrome. However little is known about the mechanisms of action of 5-HT 2 receptors in altering the activity of parasympathetic cardiac neurons in the brainstem. In this study we examined the effects of activation of different subtypes of 5-HT 2 receptors on spontaneous and respiratory evoked GABAergic neurotransmission to cardioinhibitory vagal neurons within the nucleus ambiguus as well as rhythmic fictive inspiratoryrelated activity. A single application of α-Me-5-hydroxytryptamine maleate (α-Me-5-HT), a 5-HT 2 receptor agonist, did not significantly alter the frequency of spontaneous or respiratory-evoked GABAergic inhibitory post-synaptic currents (IPSCs) in cardiac vagal neurons. However, repetitive successive applications of α-Me-5-HT elicited a long-lasting (≥ 1 hour) decrease in the frequency of spontaneous as well as inspiratory-related GABAergic IPSCs to cardiac vagal neurons. This study demonstrates multiple, but not single applications of the 5-HT 2 receptor agonist α-Me-5-HT caused a long-lasting inhibition of both spontaneous and fictive inspiratory-related GABAergic neurotransmission to CVNs which can be prevented by the 5-HT 2B receptor antagonist SB204741, but persisted with the 5-HT 2A/2C receptor antagonist ketanserin. The 5-HT 2 receptor agonist α-Me-5-HT also reversibly and transiently excited central fictive inspiratory activity which was abolished by ketanserin, but was unaffected by the 5-HT 2B receptor antagonist SB204741.

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Section: Resultssupporting

confidence: 90%

5-HT2 receptor subtypes mediate different long-term changes in GABAergic activity to parasympathetic cardiac vagal neurons in the nucleus ambiguus

et al. 2007

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“…be an important mechanism influencing the gain of cardiorespiratory responses to hypoxia and hypercarbia (Neff et al, 2004;Huang et al, 2006;Luo et al, 2007).…”

Section: Discussionmentioning

confidence: 99%

Prenatal to Early Postnatal Nicotine Exposure Impairs Central Chemoreception and Modifies Breathing Pattern in Mouse Neonates: A Probable Link to Sudden Infant Death Syndrome

Eugenı́n¹,

Otárola²,

Bravo³

et al. 2008

J. Neurosci.

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“…severe BPD), the slower will be the path to recovery and the more likely it is that there will be enduring, perhaps serious, side effects. Dysfunction of the sort we describe may be further worsened by hypoxia (which amplifies the effects of hypercapnia, and is a complication of BPD) or nicotine exposure due to maternal tobacco use (45)(46)(47).…”

Section: Discussionmentioning

confidence: 99%

Abnormal Circulatory Stress Responses of Preterm Graduates

2007

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Preterm birth and chronic lung disease may increase the risk of hypertension and cardiovascular disease in infancy and adolescence. Here we looked for evidence of early circulatory dysfunction associated with these perinatal complications. We compared infants born at term (n ϭ 12) with those born preterm with an uncomplicated neonatal course (n ϭ 12) or diagnosed with bronchopulmonary dysplasia (BPD) (n ϭ 10). We measured blood pressure (BP) (Finometer), and heart rate (HR) responses to 4 min of breathing 4% CO 2 during quiet sleep. Hypercapnia accelerated HR and increased BP of term infants. Preterm infants either (i) had an exaggerated pressor but little or no HR response to CO 2 (healthy or mild-moderate BPD) or (ii) had a diminished pressor response and accompanying decrease in HR (severe BPD). Short-term reflex cardiovascular control was consequently altered by premature birth, with potentially more serious aberrations associated with severe BPD. Most anomalies had not resolved by the time infants born preterm reached term age; some may be early signs of emerging long-term cardiovascular dysfunction. W ith the impressive increase in survival of very preterm and low birth weight infants come new challenges. Evidence already indicates that this "new generation" of children and adolescents may have accelerated disease onset later in life (1). One factor contributing to their higher risk of cardiovascular disease may be abnormal vascular and circulatory development (2-4). Cardiovascular activity is normally carefully regulated, but if some or all of the central and peripheral regulatory mechanisms involved fail to develop normally, perfusion, growth, and function may be compromised. In exceptional circumstances during infancy, persistent serious dysfunction could result in a sudden catastrophic decrease in BP and HR or prevent autoresuscitative recovery, culminating in sudden infant death syndrome (SIDS) (5,6). In other cases, dysfunction may be relatively benign, although there may still be side effects with adverse consequences of their own.We know relatively little about how BP and HR control develops, and the potentially adverse effects of fetal and perinatal stress. A better understanding of these issues could lead to new therapies or strategies to prevent neonatal complications and improve long-term outcome. In the study described here, we looked for evidence that development of neonatal circulatory control is altered by common perinatal complications (7). We studied three different groups of newborn infants: those born normally at term, those born preterm but otherwise healthy, and infants born very preterm suffering from chronic lung disease (BPD). Infants with BPD are at particularly high risk of long-term cardiovascular complications and SIDS (8 -10). We compared BP and HR responses of these infants to a routine physiologic stress (breathing a low concentration of CO 2 for several minutes) commonly used to unmask autonomic anomalies (11). Normally, acute exposure to CO 2 increases BP and HR ...

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Differential Control of Central Cardiorespiratory Interactions by Hypercapnia and the Effect of Prenatal Nicotine

Cited by 30 publications

References 49 publications

5-HT2 receptor subtypes mediate different long-term changes in GABAergic activity to parasympathetic cardiac vagal neurons in the nucleus ambiguus

5-HT2 receptor subtypes mediate different long-term changes in GABAergic activity to parasympathetic cardiac vagal neurons in the nucleus ambiguus

Prenatal to Early Postnatal Nicotine Exposure Impairs Central Chemoreception and Modifies Breathing Pattern in Mouse Neonates: A Probable Link to Sudden Infant Death Syndrome

Abnormal Circulatory Stress Responses of Preterm Graduates

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