Biology subjects

Daffre, C.

Publications and source records attributed to Daffre, C..

3 recordsLinked to original sources

bioRxiv2026

Vagally Mediated Heart Rate Variability During REM Sleep is Associated with Retention of Fear Extinction in Generalized Anxiety Disorder

Fear extinction processes are central to the pathology and treatment of anxiety disorders. Emerging evidence implicates rapid eye movement (REM) sleep in the consolidation of extinction memory. Separately, converging theory and empirical work suggest that vagally mediated heart rate variability (VmHRV) serves as a peripheral index of cortico-subcortical regulatory capacity relevant to extinction circuitry. On this basis, we tested the hypothesis that VmHRV during REM sleep would be associated with the retention of extinction memory in individuals with generalized anxiety disorder (GAD). Participants underwent a validated two-day fear conditioning and extinction paradigm. Subjective extinction retention (sERI) was quantified during a recall test 24 hours after learning and ambulatory polysomnography was recorded on the intervening night. As hypothesized, higher REM VmHRV was significantly associated with better extinction retention. This association remained robust after controlling psychotropic medication use and REM density. In contrast, VmHRV during SWS or wakefulness, as well as other REM sleep measures, were not associated with extinction retention. These findings identify REM VmHRV as a significant predictor of extinction memory retention in GAD, extending prior findings in trauma-exposed individuals. We propose that reduced vagal tone indexes compromised prefrontal inhibitory control over amygdala and noradrenergic circuits, thereby impairing REM sleep-dependent consolidation. These results position VmHRV during REM sleep as a potential transdiagnostic biomarker of extinction memory processing and suggest that interventions enhancing vagal tone could improve treatment outcomes in anxiety disorders.

neuroscience↗

bioRxiv2025

Local and network neural activations and their associations with sleep parameters during threat conditioning and extinction in persons with Generalized Anxiety Disorder with and without Insomnia Disorder

Deficient extinction learning and memory are hypothesized mechanisms for pathological anxiety that are associated with sleep disturbance. fMRI neural activations to threat conditioning, extinction learning, and extinction recall were measured. Activations were compared, in persons with Generalized Anxiety Disorder (GAD), between those with moderate to severe Insomnia Disorder (ID) and those with absent or sub-threshold ID. Relationships of activations with measures of sleep quality and physiology were examined. Between-group comparisons and whole-sample correlation with sleep parameters were examined in relation to large-scale brain networks using a liberal cluster-determining threshold. Localized activations were then identified using family-wise error correction. Activations to the reinforced stimulus (CS+) that increased from the beginning to end ("across") threat conditioning were more extensive within the GAD+ID group. Increased activations to the CS+ across extinction learning were greater within the GAD-ID than the GAD+ID group, and delayed 24h in the latter. Greater sleep efficiency was associated with decreased activations across threat conditioning, but with increased activations across extinction learning. Better sleep quality promoted greater engagement of neural substrates of extinction learning. The GAD+ID group failed to engage brain areas supporting extinction learning immediately following threat conditioning, but did so when stimuli were again presented following a delay. HighlightsGeneralized Anxiety Disorder subjects with moderate/severe vs absent/mild insomnia compared Neural responses to threat conditioning, extinction learning/memory analyzed and sleep recorded Low and high thresholds identified large-scale networks and localized activations respectively Threat and regulatory activations at extinction learning in mild insomnia delayed when more severe Better sleep quality predicted greater activation of regulatory areas during extinction learning

neuroscience↗

bioRxiv2023

REM Sleep Measures and REM Vagal Activity Predict Extinction Recall in Trauma-Exposed Individuals

Accumulating evidence suggests that rapid eye movement sleep (REM) supports the consolidation of extinction memory. REM is disrupted in PTSD, and REM abnormalities after traumatic events increase the risk of developing PTSD. Therefore, it was hypothesized that abnormal REM in trauma-exposed individuals may pave the way for PTSD by interfering with the processing of extinction memory. In addition, PTSD patients display reduced vagal activity. Vagal activity contributes to the strengthening of memories, including fear extinction memory, and recent studies show that the role of vagus in memory processing extends to memory consolidation during sleep. Therefore, it is plausible that reduced vagal activity during sleep in trauma-exposed individuals may be an additional mechanism that impairs extinction memory consolidation. However, to date, the contribution of sleep vagal activity to the consolidation of extinction memory or any emotional memory has not been investigated. To test these hypotheses, we examined the association of extinction memory with REM characteristics and REM vagal activity (indexed as heart rate variability) in a large sample of trauma-exposed individuals (n=113). Consistent with our hypotheses, REM disruption was associated with poorer physiological and explicit extinction memory. Furthermore, higher vagal activity during REM was associated with better explicit extinction memory, and physiological extinction memory in males. These findings support the notion that abnormal REM may contribute to PTSD by impairing the consolidation of extinction memory and indicate the potential utility of interventions that target REM sleep characteristics and REM vagal activity in fear-related disorders.

neuroscience↗