Control of Breathing in the Fetus and the Newborn

Bryan, A. C.; Bowes, Glenn; Maloney, J. E.

doi:10.1002/cphy.cp030218

Cited by 18 publications

(13 citation statements)

References 184 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is consistent with the observation that UA muscle activity is enhanced by vagotomy in adult animals [22,23] and suggests that the Hering-Breuer inflation reflex may have a greater inhibitory effect on UA muscle activity in young animals since geniohyoid activity was absent with intact vagi in the present experiments. In this regard, it is known that the inspiratory-inhibiting component of the Hering-Breuer reflex is more active in newborns than in adults [24]. This reflex may also explain why cooling in the present experiments had no effect on tidal volume in vagi-intact animals but caused an increase in tidal volume following vagotomy.…”

Section: Discussionsupporting

confidence: 43%

Upper airway cooling reduces upper airway resistance in anaesthetized young guinea-pigs

Curran

O’Halloran²,

Bradford³

1998

Eur Respir J

View full text Add to dashboard Cite

In adult animals, the upper airway (UA) has been shown to contain receptors sensitive to UA cooling [1][2][3][4][5]. The application of cool air to the isolated UA inhibits breathing [6][7][8][9] and this effect is abolished by laryngeal anaesthesia [6] or by cutting the superior laryngeal nerves [7][8][9]. UA cooling has also been shown to modify UA dilator muscle activity [7][8][9][10][11] and this effect was also abolished by superior laryngeal nerve section [7,9,11]. In adult rats, moderate UA cooling has been shown to increase UA dilator muscle activity and reduce UA resistance [8,9], suggesting that changes in UA temperature may play a role in the control of UA patency.The effects of UA cooling on UA muscle activity and UA resistance have not been investigated in young animals. Little is known about UA receptors in young animals, although superior laryngeal nerve afferents responding to UA pressure, airflow, UA movement and/or muscle activity have been described in neonatal dogs [12] and to water in neonatal dogs [13] and neonatal sheep, cats and monkeys [14]. UA cooling has been shown to inhibit breathing in neonatal dogs [15] and guinea-pigs [16] and possibly in neonatal cats [17], and these effects were abolished by laryngeal anaesthesia [17] or superior laryngeal nerve section [15,16]. Menthol, a specific cold receptor stimulant, also inhibits breathing in neonatal dogs [18]. It has been suggested that the ventilatory depression caused by cooling and laryngeal reflex responses to water is greater in neonates than in adults [12,13,17].The purpose of the present study was to examine the effects of UA cooling on UA dilator muscle activity and on UA resistance in young guinea-pigs. The young guineapig is known to be neurologically more mature than several other species [19]. However, it has been shown previously that UA reflex responses are very different in 10-14-day-old compared with adult guinea-pigs [20]. There are also maturational differences in local airway responses, since exsanguination-induced bronchoconstriction has been shown to be greater in 15-day-old than in adult guineapigs [21]. Materials and methodsThe procedure for isolation of the UA has been described previously [16]. In brief, 17 young guinea-pigs (Biological Laboratories Europe Ltd., Carrentrila, Ireland) aged 15.7±0.4 days with a body weight of 197.8±7.3 g (mean±SD) were anaesthetised using urethane (2 g·kg -1 i.p.) and placed supine on a thermostatically controlled heating pad to maintain body temperature at 37°C. The fur was removed from the ventral aspect of the neck and a midline incision was made, exposing the trachea. With the aid of a binocular microscope (Leica, Wild MC3, Heerbrugg, Switzerland) a low cervical tracheostomy was performed through which the animal could breathe spontaneously. Tracheal airflow was continuously recorded using a heated pneumotachograph (Hans Rudolph, KS, USA) and differential pressure transducer (Validyne DP 15, North Ridge, CA, USA) placed in series with the tracheal cannula and the signal was in...

show abstract

Section: Discussionsupporting

confidence: 43%

Upper airway cooling reduces upper airway resistance in anaesthetized young guinea-pigs

Curran

O’Halloran²,

Bradford³

1998

Eur Respir J

View full text Add to dashboard Cite

show abstract

“…The major benefit of this technique is that it can provide effective ventilation; however, because of the different upper aiJWay anatomy in infants and young children, aiJWay occlusion can occur when breaths are generated by a negative pressure ventilator during sleep, 122 and thus infants and young children often require a tracheostomy when using a negative pressure ventilator. Therefore, this technique offers little advantage over PPV in the infant or young child.…”

Section: Npv Via Chest Shell (Cuirass) or Wrap Ventilatorsmentioning

confidence: 99%

Mechanical Ventilation Beyond the Intensive Care Unit

Make¹,

Hill²,

Goldberg³

et al. 1998

Chest

197

View full text Add to dashboard Cite

“…Human infants, particularly premature infants, display frequent episodes of apnea, and bradypnea, and thus very common episodes of hypoxia during the postnatal period (Bryan et al, 1986; Carroll and Agarwal, 2010; Teppema and Dahan, 2010; Mathew, 2011). In newborn mammals, hypoxia elicits a biphasic respiratory response, characterized by a transient increase followed by a severe decline of ventilation called the hypoxic ventilatory depression (HVD; Neubauer et al, 1990; Gozal and Gaultier, 2001; Carroll and Agarwal, 2010; Teppema and Dahan, 2010).…”

Section: Introductionmentioning

confidence: 99%

Key Brainstem Structures Activated during Hypoxic Exposure in One-day-old Mice Highlight Characteristics for Modeling Breathing Network in Premature Infants

et al. 2016

View full text Add to dashboard Cite

We mapped and characterized changes in the activity of brainstem cell groups under hypoxia in one-day-old newborn mice, an animal model in which the central nervous system at birth is particularly immature. The classical biphasic respiratory response characterized by transient hyperventilation, followed by severe ventilation decline, was associated with increased c-FOS immunoreactivity in brainstem cell groups: the nucleus of the solitary tract, ventral reticular nucleus of the medulla, retrotrapezoid/parafacial region, parapyramidal group, raphe magnus nucleus, lateral, and medial parabrachial nucleus, and dorsal subcoeruleus nucleus. In contrast, the hypoglossal nucleus displayed decreased c-FOS immunoreactivity. There were fewer or no activated catecholaminergic cells activated in the medulla oblongata, whereas ~45% of the c-FOS-positive cells in the dorsal subcoeruleus were co-labeled. Approximately 30% of the c-FOS-positive cells in the parapyramidal group were serotoninergic, whereas only a small portion were labeled for serotonin in the raphe magnus nucleus. None of the c-FOS-positive cells in the retrotrapezoid/parafacial region were co-labeled for PHOX2B. Thus, the hypoxia-activated brainstem neuronal network of one-day-old mice is characterized by (i) the activation of catecholaminergic cells of the dorsal subcoeruleus nucleus, a structure implicated in the strong depressive pontine influence previously reported in the fetus but not in newborns, (ii) the weak activation of catecholaminergic cells of the ventral reticular nucleus of the medulla, an area involved in hypoxic hyperventilation, and (iii) the absence of PHOX2B-positive cells activated in the retrotrapezoid/parafacial region. Based on these results, one-day-old mice could highlight characteristics for modeling the breathing network of premature infants.

show abstract

Control of Breathing in the Fetus and the Newborn

Cited by 18 publications

References 184 publications

Upper airway cooling reduces upper airway resistance in anaesthetized young guinea-pigs

Upper airway cooling reduces upper airway resistance in anaesthetized young guinea-pigs

Mechanical Ventilation Beyond the Intensive Care Unit

Key Brainstem Structures Activated during Hypoxic Exposure in One-day-old Mice Highlight Characteristics for Modeling Breathing Network in Premature Infants

Contact Info

Product

Resources

About