Basic sleep physiology Archives - Yuval Nir Lab - מעבדת יובל ניר לחקר המוח

Polarizer-assisted pupillometry through closed eyelids, overcoming pupil position dependence

Reliable assessment of pupillary dynamics behind closed eyelids remains a central challenge for monitoring brain state in sleep, anesthesia, and unresponsive conditions. In this study we introduce a polarizer-assisted extension of short-wave infrared (SWIR) imaging that enhances contrast and signal fidelity for touchless pupillometry through closed eyes. By optimizing polarizer configurations and image-processing algorithms, we […]

SleepEEGpy: a Python-based software integration package to organize preprocessing, analysis, and visualization of sleep EEG data

Analyzing sleep EEG often requires combining multiple tools, creating a fragmented and error-prone workflow that slows research and limits reproducibility. To address this, we developed SleepEEGpy – an open-source Python package that unifies key steps in sleep EEG preprocessing and analysis into one streamlined, user-friendly framework. SleepEEGpy supports data cleaning, ICA, event detection, spectral analysis, and […]

Abrupt and Gradual Changes in Neuronal Processing upon Falling Asleep and Awakening

The neural processes associated with the transition into sleep remain poorly understood, and it is unclear whether they develop abruptly or gradually. By examining spontaneous and sound-evoked neuronal activity in the auditory cortex of rats during thousands of sleep-wake transitions, we found that stimulus-induced neuronal silence (OFF periods) emerged abruptly within seconds of sleep onset, […]

Claustrum neurons projecting to the anterior cingulate restrict engagement during sleep and behavior

This paper focuses on Claustrum, attention and sleep. We observed a consistent and robust increase in the prevalence of NREM sleep in the hours following chemogenetic activation of ACCp claustrum neurons. Next, our contribution was not only the association between elevated ACCp claustrum activity and unresponsive NREM sleep, but also a significant decrease in sound-evoked […]

A bistable inhibitory optoGPCR for multiplexed optogenetic control of neural circuits

PdCO published here is an efficient, versatile, light-activated bistable G-protein coupled receptor that can suppress synaptic transmission in mammalian neurons with high temporal precision in vivo. Our contribution is the LC to EW projection that showed asymmetric pupil constriction

Sleep-like changes in neural processing emerge during sleep deprivation in early auditory cortex

We examined which aspects of cortical processing are affected by sleep deprivation (SD), and whether they can already be identified in early sensory regions. We recorded spiking activity in rat auditory cortex along with polysomnography while presenting sounds during SD followed by recovery sleep. We found that certain aspects of auditory processing (frequency tuning, onset […]

Augmenting hippocampal–prefrontal neuronal synchrony during sleep enhances memory consolidation in humans

Sleep helps stabilize long-term memories, for example declarative hippocampal-dependent memories have been suggested to benefit from synchronization of neuronal activity in hippocampus and cortex during NREM sleep. Working with epilepsy patients implanted with intracranial electrodes for clinical reasons, we studied this process with single neuron resolution. We used electrical pulses in the prefrontal cortex, precisely […]

Parp1 promotes sleep, which enhances DNA repair in neurons

The timing, duration, and quality of sleep are regulated by an interaction between the circadian clock and homeostatic sleep pressure, which builds up during extended wakefulness. Homeostatic factors are thought to accumulate with increasing duration and intensity of wakefulness prior to sleep. In this study, a combination of behavioral monitoring and EMG/EEG recording under a […]

Claustral Projections to Anterior Cingulate Cortex Modulate Engagement with the External World

Engagement is a major determinant of performance. Hyper-engagement risks impulsivity and is fatiguing over time, while hypo-engagement could lead to missed opportunities. Even in sleep, when engagement levels are minimal, sensory responsiveness varies. Thus, maintaining an optimal engagement level with the environment is a fundamental cognitive ability. In this study we investigated the activity of […]

Locus-coeruleus norepinephrine activity mediates sensory-evoked awakenings from sleep.

A reduced responsiveness to external stimuli is the main characteristic of sleep. In this study we show that the LC, a small nucleus in the brainstem and the main source of noradrenaline, plays a central role in our ability to disconnect from the environment during sleep. We recorded rats cerebral cortical activity (Electroencephalogram; EEG) in […]