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Abstract: The Neurovisceral Integration Model is based on the premise of significant central nervous system–peripheral nervous system interactions. In support of this model we have previously shown that the prefrontal cortex tonically inhibits cardioacceleratory circuits as evidenced by increased heart rate (HR) when the prefrontal cortex is inactivated by injections of sodium amobarbitol (ISA) into the internal carotid artery. In this report we re-examine these data to investigate possible age-related differences in the prefrontal control of HR in humans. Seventy-three patients were divided into three groups based on a tertile split with mean ages of 20, 34, and 47, respectively. There were significant age-related differences in cortical control of HR as evidenced by a significant three way interaction of age (young, middle, old) by side (left versus right) by time (baseline and epochs 1–10 of inactivation) [Roy''s Root (10,59)=0.378, p =0.028]. Results showed significant HR increases that did not differ between hemispheres in the youngest age group, significant increases in the middle age group that were larger in the right hemisphere than in the left, and significant HR increases in the oldest group in the right hemisphere only. The findings suggest important age-related differences in cortical inhibitory control of HR that appear less lateralized in the youngest group and significantly attenuated in the oldest age group. These results have important implications for the understanding of age-related differences in cognitive, affective, behavioral, and physiological functioning. In addition they support the importance of investigating central nervous system–peripheral nervous system relationships. [Copyright &y& Elsevier]

Abstract: Alcoholism and heavy drinking are associated with a number of physiological, behavioral, affective, and cognitive problems. One such problem involves dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis, with alcoholics showing higher basal cortisol levels and reduced inhibitory feedback control. In addition, alcohol consumption is associated with decreased heart rate variability (HRV). In the present study we examined the relationships among alcohol consumption, cortisol excretion, and HRV in 542 apparently healthy men. Men in the top tertile of self-reported alcohol consumption had higher cortisol levels and lower HRV compared to men in the lower two tertiles of alcohol consumption. In addition, the inverse relationship between cortisol and HRV was greatly attenuated in the heavy drinking group even after accounting for a number of potential confounding factors. These results support prior research on the HPA axis dysregulation in alcoholics and suggest impaired inhibitory control of the HPA axis in heavy drinkers. The findings are consistent with the neurovisceral integration model, which links central and peripheral processes, and may provide a comprehensive framework for the future investigation of the complex mix of physiological, behavioral, affective, and cognitive factors which comprise the heavy drinking phenotype. [Copyright &y& Elsevier]

Previous studies indicate that the structure and function of medial prefrontal cortex (PFC) and lateral orbitofrontal cortex (OFC) are associated with heart rate variability (HRV). Typically, this association is assumed to reflect the PFC's role in controlling HRV and emotion regulation, with better prefrontal structural integrity supporting greater HRV and better emotion regulation. However, as a control system, the PFC must monitor and respond to heart rate oscillatory activity. Thus, engaging in regulatory feedback during heart rate oscillatory activity may over time help shape PFC structure, as relevant circuits and connections are modified. In the current study with younger and older adults, we tested whether 5 weeks of daily sessions of biofeedback to increase heart rate oscillations (Osc+ condition) vs. to decrease heart rate oscillations (Osc− condition) affected cortical volume in left OFC and right OFC, two regions particularly associated with HRV in prior studies. The left OFC showed significant differences in volume change across conditions, with Osc+ increasing volume relative to Osc−. The volume changes in left OFC were significantly correlated with changes in mood disturbance. In addition, resting low frequency HRV increased more in the Osc+ than in the Osc− condition. These findings indicate that daily biofeedback sessions regulating heart rate oscillatory activity can shape both resting HRV and the brain circuits that help control HRV and regulate emotion. • Participants completed daily HRV biofeedback sessions. • They attempted to increase or decrease HR oscillations with biofeedback. • The two conditions showed opposing changes in left OFC volume. • Training condition affected structural volume in left OFC directly. • The relationship between condition and HRV was mediated by HR oscillation. [ABSTRACT FROM AUTHOR]

Abstract: Many researchers have proposed an emotion regulation circuit that includes the prefrontal cortex and the amygdala. LeDoux (1996) has proposed that there are two pathways by which emotion information is processed. A fast route that bypasses the prefrontal cortex to allow rapid response to potential threat, and a slower route that includes the prefrontal cortex and allows modulation of bottom-up inputs. We investigated these pathways and their peripheral manifestations using emotional pictures presented for either 30milliseconds or 6seconds. 36 female participants were randomly assigned to view pleasant, unpleasant, and neutral pictures that varied in viewing time while the eyeblink startle magnitude and phasic heart rate (HR) responses were recorded. Significant Group by Valence interactions were found for both startle and heart rate responses. For the 6second condition the expected emotion modulated startle effect was found with a larger startle for unpleasant and smaller startles for pleasant foregrounds relative to neutral pictures. For HR, the D1 component was larger for pleasant and unpleasant foregrounds compared to the neutral and the A1 component was larger for the unpleasant compared to the pleasant and the neutral. For the 30 millisecond condition, startle magnitudes were larger for the pleasant and unpleasant compared to the neutral. Whereas the HR response showed the expected tri-phasic profile there were no significant between valence differences. These results suggest that briefly presented emotion stimuli access the fast route of emotion recognition perhaps via the amygdala. The 6second presentations allow the prefrontal cortex to modulate the bottom up inputs and thus produce a context appropriate response. [Copyright &y& Elsevier]

Abstract: Heart rate variability (HRV) is reduced in patients who suffer from panic disorder (PD). Reduced HRV is related to hypoactivity in the prefrontal cortex (PFC), which negatively affects executive functioning. The present study assessed the relationships between vagally mediated HRV at baseline and measures of executive functioning in 36 patients with PD. Associations between these physiological and cognitive measures and panic-related variables were also investigated. HRV was measured using HF-power (ms2), and executive functions were assessed with the Wisconsin Card Sorting Test (WCST) and the Color-Word Interference Test (CWIT) from the Delis-Kaplan Executive Function System (D-KEFS). Panic-related variables comprised panic frequency, panic-related distress, and duration of PD. Performance on the neuropsychological measures correlated significantly with HRV. Both panic-related distress and duration of PD were inversely related with measures of HRV and cognitive inhibition. The current findings support the purported relationship between HRV and executive functions involving the PFC. [Copyright &y& Elsevier]