Sleep spindles

Accumulating evidence from electrocorticogram (ECoG) recordings and imaging challenge traditional views of brain oscillations as spatially stationary periodic sources. Understanding the spatio-temporal dynamics of cortical activity requires novel measurement and analysis methodologies. We recorded broadband local field potential (LFP) across the whole neocortex in freely behaving rats using high-density flexible surface arrays using active transistors. 3D tracking and spatio-spectral analysis of recordings over long sessions enabled automatic and accurate brain and behavioral states segmentati

With advances in high-density epicortical electrophysiological recordings (i.e., ECoGs), it became possible to investigate precise spatio-temporal evolution of neural dynamics behind various cognitive functions. This improved resolution allowed for investigation of until now largely disregarded spatial features of neuronal oscillations and challenged the conventional view of global zero-lag synchrony as a basis of neuronal communication. More specifically, it revealed structured phase-offsets in superficial cortical singals corresponding to wave-like dynamics. Further investigation of single-c

Sleep deficits are often prodromal to the onset of psychiatric diseases. Such disorders, for example schizophrenia, autism spectrum disorder or attention deficit hyperactivity disorder, are strongly linked to the 22q11.2 microdeletion (22qdel). Carriers of 22qdel exhibit reduced sleep spindle formation, which correlates to decreased memory performance and disease severity. Two neurological cell populations, the noradrenergic (NA) neurons in the locus coeruleus (LC) and the parvalbumin (PV)-positive cortical interneurons are involved in the regulation of sleep spindles. However, the interplay o

Sleep deficits and altered sleep features, such as reduced NREM sleep, slow oscillations and sleep spindles are key hallmarks of many neurological disorders. Imaging studies indicate that dysregulation of thalamocortical circuits is associated with sleep abnormalities, but the underlying mechanisms remain poorly understood. Therefore, we studied the impact of thalamic hyperactivity on sleep physiology in rats using chemogenetics.Rats were injected with AAVs to express hM3Dq in either the mediodorsal (MDT), ventroposterior (VPT) or ventromedial thalamus (VMT). Electrodes were implanted in front

Accumulating evidence from electrocorticogram (ECoG) recordings and imaging challenge traditional views of brain oscillations as spatially stationary periodic sources. Understanding the spatio-temporal dynamics of cortical activity requires novel measurement and analysis methodologies. We recorded broadband local field potential (LFP) across the whole neocortex in freely behaving rats using high-density flexible surface and translaminar arrays using active transistors. 3D tracking and spatio-spectral analysis of recordings over long sessions enabled automatic and accurate brain and behavioral

We aimed to examine the effect of sex on maturational changes in sleep neurophysiology indexed by polysomnography in children with neurodevelopmental disorders(NDD) compared to non-NDD individuals. We utilized whole-night polysomnography data from a large pediatric (2.5 to 17.5 years) sample available at the National Sleep Research Resource. Using ICD codes, we defined the NDD subsets for ASD(N=196), ADHD(N=525), intellectual disabilities(ID, N=167), and a no-NDD sample(N=1523). The open-source package Luna was used to derive multiple sleep features, including sleep spindles, slow oscillations

During sleep, memories formed in the hippocampus when awake are progressively transferred to the neocortex, where they are reorganised and stabilised to become long-term memories. This consolidation process is believed to occur concurrently with neuronal oscillations such as sleep spindles. Spindles are waxing-and-waning oscillations in the 10-16 Hz frequency range recorded from the brain's surface, originating in the thalamus and transmitted to the neocortex via thalamo-cortical projections. Several types of spindles have been identified, but how they are linked to specific consolidation proc

…Sleep and neural activity during sleep are highly temperature-dependent. During anesthetized in vivo measurements, the low-frequency components increase compared to vigilance. Therefore, we examined the changes in the frequency bands corresponding to delta and theta waves and sleep spindles during continuous infrared stimulation. The experimental device used for INM was a sharp-tip optrode, that holds an embedded waveguide that transmits in

Overgeneralization and sleep quality disruption are major components of anxiety and post-traumatic stress disorder (PTSD). This study attempts to elucidate potential links between these elements. We designed a paradigm wherein participants learned associations between three faces and positive, negative, or neutral outcomes. Subsequently, we evaluated their generalization of these faces by examining responses to morphed faces resembling the initially associated faces before and after consolidation during daytime wakefulness or full-night sleep. Our findings reveal that post-sleep, participants

Post-traumatic stress disorder affects millions worldwide, with low therapeutic success. Research confirms the involvement of memory processes in pathological and persistent traumatic memories that are difficult to overwrite. Previously, in an animal model, we demonstrated that the extinction can be expedited by closed-loop (CL) stimulation of the medial forebrain bundle (MFB) triggered by sharp-wave ripple (SWR) patterns. Similarly, stimulation of the infralimbic cortex (IL) timed to SWR also maintained a low level of fear response over the long term.We aimed to investigate if the manipulatio

…studies have identified alterations in sleep spindles as potential inheritable bioma

While sleeping, many vertebrate groups alternate between at least two sleep stages: rapid eye movement (REM) and slow wave sleep (SWS), in part characterized by wake-like and synchronous brain activity respectively. Sleep stage alternation has been implicated in learning and memory function experimentally1, and has motivated several techniques in training artificial neural networks2. If the functions ascribed to 2-stage sleep are truly general, one might expect to find similar phenomena outside the vertebrate lineage. Here we delineate neural and behavioral correlates of 2-stage sleep in octop

…and correlated with disruption in sleep spindles and emergence of epilepti

50 years ago it was found that sleep somehow made memories better and more permanent, but neither sleep nor memory researchers knew enough about sleep and memory to devise robust, effective tests. Today the fields of sleep and memory have grown and what is now understood is astounding. Still, great mysteries remain. What is the functional difference between the subtly different slow oscillation vs the slow wave of sleep and do they really have opposite memory consolidation effects? How do short spindles (e.g. <0.5 s as in schizophrenia) differ in function from longer ones and are longer spindl