Uncovering complex central autonomic networks at rest: a functional magnetic resonance imaging study on complex cardiovascular oscillations

Abstract

<jats:p>This study aims to uncover brain areas that are functionally linked to complex cardiovascular oscillations in resting-state conditions. Multi-session functional magnetic resonance imaging (fMRI) and cardiovascular data were gathered from 34 healthy volunteers recruited within the human connectome project (the ‘100-unrelated subjects' release). Group-wise multi-level fMRI analyses in conjunction with complex instantaneous heartbeat correlates (entropy and Lyapunov exponent) revealed the existence of a specialized brain network, i.e. a complex central autonomic network (CCAN), reflecting what we refer to as complex autonomic control of the heart. Our results reveal CCAN areas comprised the paracingulate and cingulate gyri, temporal gyrus, frontal orbital cortex, planum temporale, temporal fusiform, superior and middle frontal gyri, lateral occipital cortex, angular gyrus, precuneous cortex, frontal pole, intracalcarine and supracalcarine cortices, parahippocampal gyrus and left hippocampus. The CCAN visible at rest does not include the insular cortex, thalamus, putamen, amygdala and right caudate, which are classical CAN regions peculiar to sympatho-vagal control. Our results also suggest that the CCAN is mainly involved in complex vagal control mechanisms, with possible links with emotional processing networks.</jats:p>

Altered Relationship Between Heart Rate Variability and fMRI-Based Functional Connectivity in People With Epilepsy

“…These findings support the role of thalamus, insula and putamen in autonomic control, as shown in previous studies (17,20,30,53), and add roles for the temporal gyrus whose role in cardiac regulation has been recently suggested (29,37). Despite the well-established association of activity in amygdala with heart rate fluctuations in task-based experiments (17, 54), no association was observed here.…”

Regional microglial populations in central autonomic brain regions in SUDEP

“…7 Knowledge of their interconnectivity and function associated with specific regions continues to evolve. 8,9 Recent functional MRI analyses from SUDEP cases, in addition to people with epilepsy considered at higher risk, have shown altered connectivity between autonomic cortical and subcortical cardiac and respiratory regulatory regions, including the thalamus, suggesting disorganization of interconnections. [10][11][12][13] Structural MRI analyses from large data sets (ENIGMA-epilepsy consortium) recognize stereotypical regional patterns of cortical thinning in epilepsy syndromes.…”

“…A group of supratentorial brain regions involved in autonomic modulation and control of brainstem centers has been referred to as the central autonomic network (CAN) 7 . Knowledge of their interconnectivity and function associated with specific regions continues to evolve 8,9 . Recent functional MRI analyses from SUDEP cases, in addition to people with epilepsy considered at higher risk, have shown altered connectivity between autonomic cortical and subcortical cardiac and respiratory regulatory regions, including the thalamus, suggesting disorganization of interconnections 10‐13 …”

Autonomic function in amnestic and non-amnestic mild cognitive impairment: spectral heart rate variability analysis provides evidence for a brain–heart axis

“…In humans, functional neuroimaging studies have demonstrated activation of the hippocampus during sympathetic challenges 31 as well as negative correlations of parasympathetic HRV with hippocampal activity 30 and with the grey matter volume of the parahippocampal gyrus 33 . A recent neuroimaging investigation 40 has reported a negative correlation between the activity in the hippocampus and an HRV complexity index which decreases with sympathetic activation 41 .…”