ELSC Seminar Series

In this talk, I will present recent studies in our lab, where new tools are pushing the
boundaries of sleep research.
In a first line of studies, we are investigating how sleep promotes memory
consolidation in humans. To this end, we developed a novel ecological paradigm to
study episodic memory without report; upon repeated viewing of special movies,
eye gaze patterns can quantify memory for specific events. Next, we show that deep
brain closed-loop intracranial electrical stimulation during human sleep enhances
hippocampus-cortex synchrony and memory performance. Finally, we examine how
sleep and memory are disrupted in amnestic mild cognitive impairment (aMCI)
representing early Alzheimer’s disease (AD). To this end, we developed a novel
machine learning-based method to non-invasively detect interictal spikes occurring
in the medial temporal lobe during sleep. This approach can help identify disruptions
in hippocampus-cortex synchrony and memory consolidation during sleep.
In the second line of studies, we investigate how reduced locus coeruleus-
noradrenaline (LC-NE) activity during sleep mediates sensory disconnection. In
rodents, the level of ongoing tonic LC activity during sleep anticipates sound-evoked
awakenings, while minimal optogenetic LC activation or silencing increases and
decreases such awakenings, respectively. Projection-specific investigation in mice
indicates that an early surge of brainstem NE is particularly important for mediating
sensory-evoked awakenings. These findings may shift how we view arousal-
promoting neuromodulation; rather than acting in a diffuse hormonal-like manner,
the LC-NE system may in fact operate through specific projection pathways, in a
circuit-like manner. Finally, I will describe a novel method for monitoring gaze
direction and pupil size through closed eyes in humans via short-wave infrared
(SWIR) imaging in combination with video analysis algorithms. This technology has
potential to enable touchless and continuous monitoring of depth of anesthesia,
pain, and detection of intraoperative awareness.