The role of the autonomic nervous system in secretory
immunoglobulin A (sIgA) responses to laboratory challenge
was explored in a study in which sIgA and cardiovascular
activity were recorded at rest and during mental arithmetic
and paced breathing. These tasks were selected to preferentially
engage the sympathetic and parasympathetic nervous systems,
respectively. Mental arithmetic elicited a mixed pattern
of increased alpha- and beta-adrenergic activity and a
reduction in parasympathetic activity; diastolic blood
pressure, total peripheral resistance, and systolic blood
pressure increased, preejection period shortened, and heart
rate variability decreased. In contrast, paced breathing
primarily elicited an increase in parasympathetic activity;
heart rate variability increased. Mental arithmetic also
provoked an increase in sIgA concentration but no change
in saliva volume, whereas paced breathing affected neither
sIgA concentration nor saliva volume. These data suggest
that sIgA responses to laboratory challenges are mediated
by sympathetic rather than parasympathetic processes.

Background
A chronic imbalance of the autonomic nervous system(ANS) may contribute to long term complications in different congenital heart diseases. The purpose of this study was to determine whether the ANS plays a role in the long-term outcome of patients with Transposition of great arteries(TGA) after arterial switch operation(ASO) as its contribution is as yet not clear.
Methods
The ANS activity was evaluated non-invasively in 26 TGA patients and 52 age-appropriate healthy subjects combining impedance cardiography and electrocardiography. Heart rate, pre-ejection period(sympathetic activity parameter) and respiratory sinus arrhythmia and the root of the mean square of successive normal-to-normal interval differences(parasympathetic activity parameter) were measured during 5 different daily activities(sleep, sitting, active sitting, light and moderate/vigorous physical activity). Whether the ANS activity was related to ventricular function, exercise test performance or clinical outcome in the patient group was also analyzed.
Results
Compared to healthy subjects: heart rate was significantly lower in TGA patients at rest and during quiet and active sitting; sympathetic activity was significantly reduced in patients during physical activity; and the parasympathetic activity was higher in TGA patients while quiet and active sitting. In the patient group a significant positive correlation between 4-chamber longitudinal strain and parasympathetic activity during 3 different daily activities was found.
Conclusions
The sympathetic nervous system response to physical activity is reduced in TGA patients after ASO. Additionally, we observed a positive correlation between better left ventricular function and higher parasympathetic activity that could be in line with the known protective effect of a higher vagal activity.

The present study addressed autonomic nervous system (ANS) patterning during experimentally manipulated emotion. Film clips previously shown to induce amusement, anger, contentment, disgust, fear and sadness, in addition to a neutral control film, were presented to 34 college-aged subjects while skin conductance, blood pressure and the electrocardiogram (ECG) were recorded, as was self-reported affect. Both mean of and mean successive difference of heart period were derived from the ECG. Pattern classification analyses revealed emotion-specific autonomic patterning for all emotion conditions except disgust; all emotion conditions exhibited significant patterning using self-report. Discriminant function analysis was used to describe the location of discrete emotions within dimensional affective space using both self-report and ANS variables. Findings suggest that the dimensions of valence and activation portray the structure of self-reported emotion, but that valence is more accurately described as approach–withdrawal when applied to autonomic responses during discrete emotions. The findings provide further support for the existence of emotion-specific ANS activity, and are consistent with a hybrid discrete–dimensional model of affective space.

Shift workers encounter an increased risk of cardiovascular disease compared to their day working counterparts. To explore this phenomenon, the effects of one week of simulated night shift on cardiac sympathetic (SNS) and parasympathetic (PNS) activity were assessed. Ten (5m; 5f) healthy subjects aged 18-29 years attended an adaptation and baseline night before commencing one week of night shift (2300-0700 h). Sleep was recorded using a standard polysomnogram and circadian phase was tracked using salivary melatonin data. During sleep, heart rate (HR), cardiac PNS activity (RMSSD) and cardiac SNS activity (pre-ejection period) were recorded. Night shift did not influence seep quality, but reduced sleep duration by a mean of 52 +/- 29 min. One week of night shift evoked a small chronic sleep debt of 5 h 14 +/- 56 min and a cumulative circadian phase delay of 5 h +/- 14 min. Night shift had no significant effect on mean HR, but mean cardiac SNS activity during sleep was consistently higher and mean cardiac PNS activity during sleep declined gradually across the week. These results suggest that shiftwork has direct and unfavourable effects on cardiac autonomic activity and that this might be one mechanism via which shiftwork increases the risk of cardiovascular disease. It is postulated that sleep loss could be one mediator of the association between shiftwork and cardiovascular health.

Melatonin has a functional role in the nocturnal regulation of sleep and thermoregulation. In addition to its action on peripheral receptors, melatonin may act by altering autonomic activity. To determine the effect of melatonin on cardiac autonomic activity, 5 mg of melatonin or placebo was orally administered to 12 young subjects at 14:00 hr, in a repeated measures design. Melatonin decreased sleep onset latency to Stage 2 sleep by 4.92+/-1.81 min (measured by Multiple Sleep Latency Tests), rectal temperature by 0.19+/-0.05 degrees C, and increased foot temperature by 0.74+/-0.45 degrees C (all P<0.05). Melatonin decreased heart rate by 3.66+/-1.68 beats/min (P<0.05) and pre-ejection period (measure of cardiac sympathetic activity) by 16.48+/-4.28 ms (P<0.05), but had no effect on respiratory sinus arrhythmia (measure of cardiac parasympathetic activity) (P>0.05). As the decrease in pre-ejection period is likely to have resulted from a decrease in blood pressure, these results do not confirm an effect of melatonin on cardiac sympathetic activity. However, the results do clearly indicate that melatonin is unlikely to drive the previously observed presleep increase in cardiac parasympathetic activity.

Objective:
To determine whether foster children showed different autonomic nervous system activity on separation and reunion than control children. Autonomic nervous system activity in foster children was examined in relation to time in placement and disinhibited attachment.
Method:
The sample included 60 foster and 50 control children between 2 and 7 years of age who participated with their caregivers in a modified Strange Situation. Heart rate, respiratory sinus arrhythmia (RSA), and pre-ejection period were monitored continuously. Foster caregivers reported disinhibited symptoms on the Disturbances of Attachment Interview.
Results:
The Strange Situation elicited less RSA reactivity in foster children. Differences in RSA, heart rate, and pre-ejection period responses on the specific separation and reunion episodes were not significant. RSA responses on separation from the stranger and on reunion with the foster caregiver were partly explained by time in placement and disinhibited attachment.
Conclusions:
Early experiences of relationship disruptions in foster children as well as short placements may have an impact on children’s adaptation to environmental and relational challenges. Stable placement may facilitate adaptive affect regulation, except for children with disinhibited symptoms.

This study examined physiological effects of separation and reunion in a sample 3- to 6-year-old children. Using continuous ambulatory recording, changes in heart rate (HR), respiratory sinus arrhythmia (RSA), and pre-ejection period (PEP) were compared across the episodes of a separation–reunion procedure based on the strange situation. RSA decreased significantly over the course of the procedure as well as on separation from the parent and not the stranger, supporting that separation from the attachment figure elicited vagal withdrawal in young children. The absence of significant PEP effects suggest that the separation–reunion procedure, and more specifically separation from the parent, was not threatening enough to activate the sympathetic nervous system, even if children were insecure attached and inhibited with regard to strangers. Some of the variability in HR increases to reunion was explained by younger age. The findings highlight the role of the ANS as a regulatory process in the parent–child relationship. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 119–128, 2007.

Chewing has been shown to alleviate feelings of sleepiness and improve cognitive performance during the day. This study investigated the effect of chewing on alertness and cognitive performance across one night without sleep as well as the possible mediating role of cardiac autonomic activity. Fourteen adults participated in a randomized, counterbalanced protocol employing a chewing, placebo and caffeine condition. Participants completed tasks assessing psychomotor vigilance, tracking, grammatical reasoning, alertness and sleepiness each hour across the night. All participants received either placebo or caffeine (200 mg), while the chewing condition also chewed on a tasteless and odorless substance for 15 min each hour. Heart rate (HR), root mean square of the successive differences in R-R intervals on the ECG (RMSSD), and preejection period (PEP) were simultaneously recorded. Alertness and cognitive performance amongst the chewing condition did not differ or were in fact worse when compared with placebo. Similarly, measures of HR and RMSSD remained the same between these two conditions; however, PEP was reduced in the later part of the night in the chewing condition compared with a relative increase for placebo. Caffeine led to improved speed and accuracy on cognitive tasks and increased alertness when compared with chewing. Relative increases in RMSSD and reductions in HR were demonstrated following caffeine; however, no change in PEP was seen. Strong associations between cardiac parasympathetic activity and complex cognitive tasks, as well as between subjective alertness and simpler cognitive tasks, suggest a differential process mediating complex versus simple cognitive performance during sleep deprivation.

The present study compared blood pressure levels between subjects with clinical anxiety and depressive disorders with healthy controls. Cross-sectional data were obtained in a large cohort study, the Netherlands Study of Depression and Anxiety (N=2981). Participants were classified as controls (N=590) or currently or remittedly depressed or anxious subjects (N=2028), of which 1384 were not and 644 were using antidepressants. Regression analyses calculated the contributions of anxiety and depressive disorders and antidepressant use to diastolic and systolic blood pressures, after controlling for multiple covariates. Heart rate and heart rate variability measures were subsequently added to test whether effects of anxiety/depression or medication were mediated by vagal control over the heart. Higher mean diastolic blood pressure was found among the current anxious subjects (β=0.932; P=0.03), although anxiety was not significantly related to hypertension risk. Remitted and current depressed subjects had a lower mean systolic blood pressure (β=−1.74, P=0.04 and β=−2.35, P=0.004, respectively) and were significantly less likely to have isolated systolic hypertension than controls. Users of tricyclic antidepressants had higher mean systolic and diastolic blood pressures and were more likely to have hypertension stage 1 (odds ratio: 1.90; 95% CI: 0.94 to 3.84; P=0.07) and stage 2 (odds ratio: 3.19; 95% CI: 1.35 to 7.59; P=0.008). Users of noradrenergic and serotonergic working antidepressants were more likely to have hypertension stage 1. This study shows that depressive disorder is associated with low systolic blood pressure and less hypertension, whereas the use of certain antidepressants is associated with both high diastolic and systolic blood pressures and hypertension.