A prominent role for amygdaloid complexes in the Variability in Heart Rate (VHR) during Rapid Eye Movement (REM) sleep relative to wakefulness

Abstract

Rapid eye movement sleep (REMS) is associated with intense neuronal activity, rapid eye movements, muscular atonia and dreaming. Another important feature in REMS is the instability in autonomic, especially in cardiovascular regulation. The neural mechanisms underpinning the variability in heart rate (VHR) during REMS are not known in detail, especially in humans. During wakefulness, the right insula has frequently been reported as involved in cardiovascular regulation but this might not be the case during REMS. We aimed at characterizing the neural correlates of VHR during REMS as compared to wakefulness and to slow wave sleep (SWS), the other main component of human sleep, in normal young adults, based on the statistical analysis of a set of H 2 15 O positron emission tomography (PET) sleep data acquired during SWS, REMS and wakefulness. The results showed that VHR correlated more tightly during REMS than during wakefulness with the rCBF in the right amygdaloid complex. Moreover, we assessed whether functional relationships between amygdala and any brain area changed depending the state of vigilance. Only the activity within in the insula was found to covary with the amygdala, significantly more tightly during wakefulness than during REMS in relation to the VHR. The functional connectivity between the amygdala and the insular cortex, two brain areas involved in cardiovascular regulation, differs significantly in REMS as compared to wakefulness. This suggests a functional reorganization of central cardiovascular regulation during REMS.

Desvenlafaxine reduces apoptosis in amygdala after myocardial infarction

“…Up to now the mechanisms linking MI to apoptosis in the lateral amygdala are unknown but we speculate that they are related to a signal triggered by the ischemic myocardium reaching the CNS. Indeed, it is known that the amygdala modulates heart rate (Yang et al, 2007) and heart rate variability (Desseilles et al, 2006), suggesting a central link between both tissues. Nervous signal is clearly a potential mechanism but other authors have claimed that heart rate variability can be related to inflammatory biomarkers such as pro-inflammatory cytokines (for review see Papaioannou et al, 2013).…”

Heart rate non linear dynamics in patients with persistent vegetative state: a preliminary report

“…It is unlikely that those findings might have depended on non-cerebral causes since patients with any possible confounding factor were excluded from the study. In fact, the strengths of this study were the strict and pre-defined criteria that allowed excluding patients with cardiac comorbidities and documented insular, diencephalic or brainstem focal lesions frequently associated with autonomic dysfunction manifesting as sympathetic storm, RR' changes and impaired HR variability [10,[17][18][19][20][21][22].…”

Sleep and dreaming are for important matters

“…Amygdala, along with the brainstem, form interactions involved in cardiovascular regulation during sleep (Desseilles et al, 2006) and could reflect responses to intense emotions, in particular fear and anxiety, often experienced in dreams (Schwartz and Maquet, 2002; Smith et al, 2004). Amygdala connections with HC, thalamus, the septal nuclei, mPFC and ACC may also have an important role in strengthening affective value associated to memories (Sterpenich et al, 2007, 2009).…”