Biology subjects

Talamini, L.

Publications and source records attributed to Talamini, L..

4 recordsLinked to original sources

bioRxiv2026

Theta phase-locked memory reactivation during REM sleep reduces memories emotional tone

REM sleep appears to be involved in emotional memory processing, yet the nature and neural underpinnings of this involvement remain largely unclear. Recent findings suggest REM-related theta activity may play a central role. To test this, we developed an automated protocol to target non-arousing acoustic memory cues to specific phases of REM sleep theta oscillations. During sleep, participants who had undergone a fear conditioning procedure combined with a memory recollection and emotional evaluation task, were re-exposed to conditioned stimuli, timed to either the upswing or downswing of theta waves. Both up- and down-targeted memory cues significantly enhanced the theta dynamic. Moreover, theta phase-locked memory reactivation significantly reduced the emotional tone of conditioned memories compared to sham reactivation (no acoustic memory cue), without affecting recognition performance or dream qualities. This constitutes the first evidence that REM sleep theta oscillations are causally involved in emotional memory processing, specifically in attenuating memories emotional charge. These findings have important implications for understanding emotional memory consolidation and may lead to therapeutic applications in disorders featuring maladaptive emotional memories.

neuroscience↗

bioRxiv2025

Functional connectivity drifts during sleep as a marker of fluctuations in the level of consciousness

During the wake-sleep cycle, consciousness waxes and wanes, and this is thought to be reflected in varying levels of integration between brain areas. Recent studies challenged the notion that consciousness is homogeneously present or absent in a brain state, as exemplified by conscious reports found in otherwise unconscious Non-REM sleep. We tested if functional connectivity between neurons varies within brain states in a way compatible with a fluctuating level of consciousness. We examined directed functional connectivity between neurons across the wake-sleep cycle in rats, at a scale of a few seconds. We analyzed patterns of functional connectivity to determine if Non-REM sleep contains epochs in which inter-areal integration is comparable to that observed in wakefulness and REM sleep, and vice versa. This study will potentially reveal if circuit-level connectivity patterns are observed during sleep stages, in line with the presence of an alternation between levels of consciousness not only between but also within brain states.

neuroscience↗

bioRxiv2023

Boosting sleep slow waves suppresses dreaming

Previous findings suggest a negative correlation between slow oscillations (SO) in posterior brain regions and dreaming. Here we use a precise closed-loop auditory stimulation (CLAS) procedure to causally test whether slow oscillations suppress dreaming. Our results show that boosting posterior SO during NREM sleep decreases the likelihood of dreaming as compared to no SO boosting. This study provides the first causal evidence for the neural correlates of dreaming.

neuroscience↗

bioRxiv2021

The looping lullaby: closed-loop neurostimulation decreases sleepers' sensitivity to environmental noise

Study ObjectiveSleep is critical for physical and mental health. However, sleep disruption due to noise is a growing problem, causing long-lasting distress and fragilizing entire populations mentally and physically. Here for the first time, we tested an innovative and non-invasive potential countermeasure for sleep disruptions due to noise. MethodsWe developed a new, modeling-based, closed-loop acoustic neurostimulation procedure (CLNS) to precisely phase-lock stimuli to slow oscillations (SO). We used CLNS to align, soft sound pulses to the start of the SO positive deflection to boost SO and sleep spindles during non-rapid eye movement (NREM) sleep. Participants underwent three overnight EEG recordings. The first night served to determine each participants individual noise arousal threshold. The remaining two nights occurred in counterbalanced order: in the "Disturbing night", loud, real-life noises were repeatedly presented; in the "Intervention night", similar loud noises were played while using the CLNS to boost SO. All experimental manipulations were performed in the first three hours of sleep; participants slept undisturbed for the rest of the night. ResultsIn contrast to the Disturbing night, the probability of arousals caused by noise was significantly decreased in the Intervention night. Moreover, the CLNS intervention increased NREM duration and sleep spindle power across the night. ConclusionsThese results show that our CLNS procedure can effectively protect sleep from disruptions caused by noise. Remarkably, even in the presence of loud environmental noise, CLNS soft and precisely timed sound pulses played a beneficial role in protecting sleep continuity. This represents the first successful attempt at using CLNS in a noisy environment. Statement of SignificanceExposure to noise during sleep impairs sleep quality, leading to impaired biological functioning, decreased day-time performance and higher occurrence of accidents. Slow wave sleep is hallmarked by slow oscillations (SO) and sleep spindles, both of which are markers of sleep stability. In previous experiments, acoustic stimulation has shown potential in enhancing SO and sleep spindles. Whether these manipulations also work to stabilize sleep against the disrupting effects of environmental noise remains unclear. Here we use a new closed-loop approach to precisely align subtle acoustic stimuli with SO phase. We show that this method effectively stabilizes sleep in the presence of noise. Our results bear crucial relevance for improving sleep in the general public and in many high-risk professions.

neuroscience↗