scholarly journals Nicotinic Receptors in the Brainstem Ascending Arousal System in SIDS With Analysis of Pre-natal Exposures to Maternal Smoking and Alcohol in High-Risk Populations of the Safe Passage Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Arunnjah Vivekanandarajah ◽  
Morgan E. Nelson ◽  
Hannah C. Kinney ◽  
Amy J. Elliott ◽  
Rebecca D. Folkerth ◽  
...  

Pre-natal exposures to nicotine and alcohol are known risk factors for sudden infant death syndrome (SIDS), the leading cause of post-neonatal infant mortality. Here, we present data on nicotinic receptor binding, as determined by 125I-epibatidine receptor autoradiography, in the brainstems of infants dying of SIDS and of other known causes of death collected from the Safe Passage Study, a prospective, multicenter study with clinical sites in Cape Town, South Africa and 5 United States sites, including 2 American Indian Reservations. We examined 15 pons and medulla regions related to cardiovascular control and arousal in infants dying of SIDS (n = 12) and infants dying from known causes (n = 20, 10 pre-discharge from time of birth, 10 post-discharge). Overall, there was a developmental decrease in 125I-epibatidine binding with increasing postconceptional age in 5 medullary sites [raphe obscurus, gigantocellularis, paragigantocellularis, centralis, and dorsal accessory olive (p = 0.0002–0.03)], three of which are nuclei containing serotonin cells. Comparing SIDS with post-discharge known cause of death (post-KCOD) controls, we found significant decreased binding in SIDS in the nucleus pontis oralis (p = 0.02), a critical component of the cholinergic ascending arousal system of the rostral pons (post-KCOD, 12.1 ± 0.9 fmol/mg and SIDS, 9.1 ± 0.78 fmol/mg). In addition, we found an effect of maternal smoking in SIDS (n = 11) combined with post-KCOD controls (n = 8) on the raphe obscurus (p = 0.01), gigantocellularis (p = 0.02), and the paragigantocellularis (p = 0.002), three medullary sites found in this study to have decreased binding with age and found in previous studies to have abnormal indices of serotonin neurotransmission in SIDS infants. At these sites, 125I-epibatidine binding increased with increasing cigarettes per week. We found no effect of maternal drinking on 125I-epibatidine binding at any site measured. Taken together, these data support changes in nicotinic receptor binding related to development, cause of death, and exposure to maternal cigarette smoking. These data present new evidence in a prospective study supporting the roles of developmental factors, as well as adverse exposure on nicotinic receptors, in serotonergic nuclei of the rostral medulla—a finding that highlights the interwoven and complex relationship between acetylcholine (via nicotinic receptors) and serotonergic neurotransmission in the medulla.

2004 ◽  
Vol 92 (4) ◽  
pp. 2548-2554 ◽  
Author(s):  
Zheng-Gui Huang ◽  
Xin Wang ◽  
Cory Evans ◽  
Allison Gold ◽  
Evguenia Bouairi ◽  
...  

Nicotinic receptors play an important role in modulating the activity of parasympathetic cardiac vagal neurons in the medulla. Previous work has shown nicotine acts via at least three mechanisms to excite brain stem premotor cardiac vagal neurons. Nicotine evokes a direct increase in holding current and facilitates both the frequency and amplitude of glutamatergic neurotransmission to cardiac vagal neurons. This study tests whether these nicotinic receptor–mediated responses are endogenously active, whether α4β2 and α7 nicotinic receptors are involved, and whether prenatal exposure to nicotine alters the magnitude of these responses and the types of nicotinic receptors involved. Application of neostigmine (10 μM) significantly increased the holding current, amplitude, and frequency of miniature excitatory postsynaptic current (mEPSC) glutamatergic events in cardiac vagal neurons. In unexposed animals, the nicotine-evoked facilitation of mEPSC frequency, but not mEPSC amplitude or holding current, was blocked by α-bungarotoxin (100 nM). Prenatal nicotine exposure significantly exaggerated and altered the types of nicotinic receptors involved in these responses. In prenatal nicotine-exposed animals, α-bungarotoxin only partially reduced the increase in mEPSC frequency. In addition, in prenatal nicotine-exposed animals, the increase in holding current was partially dependent on α-7 subunit–containing nicotinic receptors, in contrast to unexposed animals in which α-bungarotoxin had no effect. These results indicate prenatal nicotine exposure, one of the highest risk factors for sudden infant death syndrome (SIDS), exaggerates the responses and changes the types of nicotinic receptors involved in exciting premotor cardiac vagal neurons. These alterations could be responsible for the pronounced bradycardia that occurs during apnea in SIDS victims.


PEDIATRICS ◽  
1996 ◽  
Vol 98 (4) ◽  
pp. 668-672
Author(s):  
Ernest Cutz ◽  
Donald G. Perrin ◽  
Richard Hackman ◽  
Elinor N. Czegledy-Nagy

Background. Maternal smoking is a well-recognized risk factor for sudden infant death syndrome (SIDS), but the precise mechanism is unknown. We tested a hypothesis that maternal smoking affects pulmonary neuroendocrine cells (PNECs) and neuroepithelial bodies (NEBs), which are innervated PNEC clusters and presumed airway chemoreceptors. Methods. Lung sections from infants who died of SIDS and whose mothers smoked during pregnancy (n = 22), infants who died of SIDS and whose mothers were nonsmokers (n = 17), and age-matched control infants (n = 15) who died of other causes were immunostained for bombesin (a PNEC and NEB marker) and assessed morphometrically. Results. The frequency of PNEC (the percentage of airway epithelium immunoreactive for bombesin) was increased up to twofold in the lungs of infants who died of SIDS (7.7 ± 0.4%) compared with controls (4.9 ± 0.4%), as was the frequency (40 ± 3.5 vs 23 ± 3.7/cm2) and size (748 ± 46.5 vs 491 ± 25.8,µm2) of NEBs. In infants who died of SIDS and who were born to smoking mothers, PNEC frequency was increased significantly compared with that in those born to nonsmoking mothers, but the frequency and size of NEBs were not significantly different between the two groups. Conclusion. Our findings suggest that maternal smoking potentiates hyperplasia of the PNEC system in the lungs of infants who die of SIDS and that a dysfunction of these cells may contribute to the pathophysiology of SIDS.


PEDIATRICS ◽  
1993 ◽  
Vol 91 (5) ◽  
pp. 893-896 ◽  
Author(s):  
E. A. Mitchell ◽  
R. P. K. Ford ◽  
A. W. Stewart ◽  
B. J. Taylor ◽  
D. M. O. Becroft ◽  
...  

Objective. Maternal smoking has been shown to be a risk factor for sudden infant death syndrome (SIDS). The effect of smoking by the father and other household members has not previously been examined. Methods. A large nationwide case-control study. Four hundred eighty-five SIDS deaths in the postneonatal age group were compared with 1800 control infants. Results. Infants of mothers who smoked during pregnancy had a 4.09 (95% confidence interval [CI] = 3.28, 5.11) greater risk of death than infants of mothers who did not smoke. Infants of mothers who smoked postnatally also had an increased risk of SIDS compared with infants of nonsmokers and, furthermore, the risk increased with increasing levels of maternal smoking. Smoking by the father and other household members increased the risk (odds ratio [OR] = 2.41, 95% CI = 1.92, 3.02 and OR = 1.54, 95% CI = 1.20, 1.99, respectively). Smoking by the father increased the risk of SIDS if the mother smoked, but had no effect if she did not smoke. In analyses controlled for a wide range of potential confounders, smoking by the mother and father was still significantly associated with an increased risk of SIDS. Conclusion. Passive tobacco smoking is causally related to SIDS.


Author(s):  
Ian Mitchell ◽  
Daniel Y Wang ◽  
Christine Troskie ◽  
Lisa Loczy ◽  
Abby Li ◽  
...  

Abstract Objectives Risk factors for sudden infant death syndrome include premature birth, maternal smoking, prone or side sleeping position, sleeping with blankets, sharing a sleeping surface with an adult, and sleeping without an adult in the room. In this study, we compare parents’ responses on sleep patterns in premature and term infants with medical complexity. Methods Parents of children enrolled in the Canadian Respiratory Syncytial Virus Evaluation Study of Palivizumab were phoned monthly regarding their child’s health status until the end of each respiratory syncytial virus season. Baseline data were obtained on patient demographics, medical history, and neonatal course. Responses on adherence to safe sleep recommendations were recorded as part of the assessment. Results A total of 2,526 preterms and 670 term infants with medical complexity were enrolled. Statistically significant differences were found in maternal smoking rates between the two groups: 13.3% (preterm); 9.3% (term) infants (χ 2=8.1, df=1, P=0.004) and with respect to toys in the crib: 12.3% (term) versus 5.8% preterms (χ 2=24.5, df=1, P<0.0005). Preterm infants were also significantly more likely to be placed prone to sleep (8.8%), compared with term infants (3.3%), (χ 2=18.1, df=1, P<0.0005). Conclusion All the infants in this study had frequent medical contacts. There is a greater prevalence of some risk factors for sudden infant death syndrome in preterm infants compared to term infants with medical complexity. Specific educational interventions for vulnerable infants may be necessary.


2020 ◽  
Vol 10 (1) ◽  
pp. 24-44
Author(s):  
Sandra P. Small ◽  
Andrea Brennan-Hunter ◽  
Caroline Porr ◽  
Yanqing Yi

Maternal smoking during pregnancy and maternal smoking postnatally are important public health concerns worldwide. Smoking adversely affects the woman's general health and is causally related to pregnancy complications and serious health outcomes for the child, such as stillbirth, preterm delivery, low birth weight, and sudden infant death. The purpose of this research was to examine maternal smoking through a quantitative descriptive survey of 164 women, 120 who were pregnant and 44 who were postnatal. Women experienced barriers to quitting smoking, including dealing with stress, being exposed to smokers, not being ready to quit, not knowing how to quit, not looking for or not being able to find information about smoking or quitting smoking, and lacking adequate social and healthcare provider support. On the other hand, women revealed characteristics that suggest they might have had improved potential for quitting smoking, including having negative feelings about smoking, having cut down on smoking, smoking at a low level, having made quit attempts, thinking it would not be hard to quit smoking, being in the preparation stage of behavioral change, and thinking their healthcare providers (HCPs) would help them if they decided to quit. Taken together, those findings suggest that HCPs could offer important assistance to help women achieve smoking cessation. However, more research needs to be conducted to clarify the role and effectiveness of various HCPs in smoking cessation interventions and to identify measures to strengthen their provision of such interventions.


Sign in / Sign up

Export Citation Format

Share Document