Division of Development and Growth, Department of Pediatrics, Obstetrics and Gynaecology, University of Geneva, Geneva, Switzerland.
Laboratory of Cognitive Neurorehabilitation, Division of Neurorehabilitation, University of Geneva, Geneva, Switzerland.
Pediatr Res. 2021 Apr;89(5):1239-1244. doi: 10.1038/s41390-020-1048-6. Epub 2020 Jul 6.
Excessive and inconsolable crying behavior in otherwise healthy infants (a condition called infant colic (IC)) is very distressing to parents, may lead to maternal depression, and in extreme cases, may result in shaken baby syndrome. Despite the high prevalence of this condition (20% of healthy infants), the underlying neural mechanisms of IC are still unknown.
By employing the latest magnetic resonance imaging (MRI) techniques in newborns, we prospectively investigated whether newborns' early brain responses to a sensory stimulus (smell) is associated with a subsequent crying behavior.
In our sample population of 21 healthy breastfed newborns, those who developed IC at 6 weeks exhibited brain activation and functional connectivity in primary and secondary olfactory brain areas that were distinct from those in babies that did not develop IC. Different activation in brain regions known to be involved in sensory integration was also observed in colicky babies. These responses measured shortly after birth were highly correlated with the mean crying time at 6 weeks of age.
Our results offer novel insights into IC pathophysiology by demonstrating that, shortly after birth, the central nervous system of babies developing IC has already greater reactivity to sensory stimuli than that of their noncolicky peers.
Shortly after birth, the central nervous system of colicky infants has a greater sensitivity to olfactory stimuli than that of their noncolicky peers. This early sensitivity explains as much as 48% of their subsequent crying behavior at 6 weeks of life. Brain activation patterns to olfactory stimuli in colicky infants include not only primary olfactory areas but also brain regions involved in pain processing, emotional valence attribution, and self-regulation. This study links earlier findings in fields as diverse as gastroenterology and behavioral psychology and has the potential of helping healthcare professionals to define strategies to advise families.
健康婴儿（一种称为婴儿绞痛（IC）的情况）过度和无法安慰的哭泣行为对父母来说非常痛苦，可能导致母亲抑郁，在极端情况下，可能导致摇晃婴儿综合征。尽管这种情况（20%的健康婴儿）很常见，但 IC 的潜在神经机制仍不清楚。
通过在新生儿中使用最新的磁共振成像（MRI）技术，我们前瞻性地研究了新生儿对感觉刺激（气味）的早期大脑反应是否与随后的哭泣行为有关。
在我们的 21 名健康母乳喂养的新生儿样本中，那些在 6 周时出现 IC 的婴儿，其初级和次级嗅觉脑区的大脑激活和功能连接与那些未出现 IC 的婴儿明显不同。在与感觉整合相关的已知脑区也观察到不同的激活。出生后不久测量的这些反应与 6 周龄时的平均哭泣时间高度相关。
我们的研究结果通过证明在出现 IC 的婴儿中，中枢神经系统在出生后不久对感觉刺激的反应性已经高于非绞痛婴儿，从而为 IC 病理生理学提供了新的见解。
在出生后不久，患有绞痛的婴儿的中枢神经系统对嗅觉刺激的敏感性就高于非绞痛婴儿。这种早期敏感性可以解释他们在生命的第 6 周时随后哭泣行为的 48%。绞痛婴儿对嗅觉刺激的大脑激活模式不仅包括初级嗅觉区域，还包括涉及疼痛处理、情绪价值归因和自我调节的脑区。这项研究将在胃肠病学和行为心理学等不同领域的早期发现联系起来，并有可能帮助医疗保健专业人员定义为家庭提供建议的策略。
