Exposures influencing the developing central autonomic nervous system

Abstract

Autonomic nervous system function is critical for transition from in-utero to ex-utero life and is associated with neurodevelopmental and neuropsychiatric outcomes later in life. Adverse prenatal and neonatal conditions and exposures can impair or alter ANS development and, as a result, may also impact longterm neurodevelopmental outcomes. The objective of this article is to provide a broad overview of the impact of factors that are known to influence autonomic development during the fetal and early neonatal period, including maternal mood and stress during and after pregnancy, fetal growth restriction, congenital heart disease, toxic exposures, and preterm birth. We touch briefly on the typical development of the ANS, then delve into both in-utero and exutero maternal and fetal factors that may impact developmental trajectory of the ANS and, thus, have implications in transition and in long-term developmental outcomes. While many types of exposures and conditions have been shown to impact development of the autonomic nervous system, there is still much to be learned about the mechanisms underlying these influences. In the future, more advanced neuromonitoring tools will be required to better understand autonomic development and its influence on long-term neurodevelopmental and neuropsychological function, especially during the fetal period.

Music Modulates Autonomic Nervous System Activity in Human Fetuses

“…In our opinion, this demonstrates that music, at the intensity we used (mean 50.8 dB), determinates the activation of ANS without inducing a fight-or-flight reaction, sympathetically mediated, as a simple sound stimulus does. The music-dependent relaxation-state of the fetus is achieved by the increase of CVI through the activation parasympathetic system ( 2 , 3 ).…”

“…During fetal adaptation to postnatal life, ANS acts as the main regulator of the new-born cardiovascular and respiratory systems ( 2 ). At birth, both sympathetic activation and parasympathetic modulation play a fundamental role in increasing and stabilization of arterial blood pressure, heart rate, respiratory rate, and catecholamine level ( 2 , 3 , 5 ). Some of the most serious complications affecting new-born present an altered development of the ANS ( 6 – 8 ).…”

“…Several techniques have been studied to asset the quality of ANS activity in fetal life. Since the autonomic capacity is mirrored in cardiovascular regulation, a marker widely used for evaluating ANS activity is Heart Rate Variability (HRV) ( 1 , 3 , 9 , 10 , 13 , 14 ). Analysis of HRV is used as a standard method for assessing ANS functions in adults.…”

The Relationship Between Heart Rate Recovery and Mean Platelet Volume in Healthy Individuals

“…The Heart Rate Recovery Index (HRRI), a crucial indicator of autonomic dysfunction, is calculated by the arithmetic difference between the maximum heart rate during treadmill stress testing and post-exercise resting heart rate (2). The decrease in the early rest period is related to the parasympathetic system, and the late period is more associated with the reduced effect of the sympathetic nervous system (3,4). Abnormal HRRI has been defined as a reduction by less than 12 bpm in the 1st-minute heart rate in the resting period and has been shown as an independent risk factor for cardiovascular mortality in several studies (5,6).…”

In infants with congenital heart disease autonomic dysfunction is associated with pre-operative brain injury

“…Autonomic function may be measured using signals such as heart rate, blood pressure, and respiratory rate. 26 Heart rate variability (HRV), which measures variation in beat-to-beat intervals between successive R waves on electrocardiography (ECG) recordings, is the most widely used measure of autonomic function in neonates, given the non-invasive nature of the measurement (by ECG). We use HRV in this study as a metric of ANS function in neonates with CHD.…”