Sleep-driven reorganization of excitatory and inhibitory synaptic nanoarchitecture

The National Institute of Neurological Disorders and Stroke, part of the Department of Health and Human Services National Institutes of Health, awarded $420,750 to West Virginia University Research Corporation on August 27, 2026, under the Extramural Research Programs in the Neurosciences and Neurological Disorders program (CFDA 93.853, Project Grant R21NS151357).

The award funds research into sleep-driven reorganization of excitatory and inhibitory synaptic nanoarchitecture, investigating how sleep regulates synaptic communication between neurons and the underlying plasticity mechanisms. The research addresses gaps in understanding how sleep supports learning and memory by regulating synaptic plasticity, and how sleep loss contributes to neurological conditions ranging from neurodevelopmental disorders to neurodegenerative disease. The project employs stimulated emission depletion microscopy to assess nanoscale-level organization of synaptic proteins, a method that permits simultaneous visualization of multiple synaptic protein complements that conventional microscopy cannot achieve.

Work is performed at Everettville, West Virginia. The period of performance runs through July 31, 2028. This is a Project Grant, an assistance type supporting discrete research projects under NINDS's mission to reduce the burden of neurological disease through fundamental knowledge of the brain and nervous system.

Abstract

Sleep loss is a prevalent problem that is caused by many environmental, social, and health factors. In particular, sleep disruption is common in many neurological conditions, ranging from neurodevelopmental disorders to neurodegenerative disease. However, our understanding of the role of sleep loss in these conditions is limited because sleep function under typical conditions is incompletely understood. Prominent theories posit that sleep plays a crucial role in learning and memory by regulating synaptic plasticity, but the underlying mechanisms are debated. Sleep has been proposed to support learning either by consolidating plastic changes that were induced during prior waking, or by homeostatically downregulating synapses to improve signal-to-noise and restore resources for subsequent learning. Establishing the mechanisms by which sleep supports brain function under typical conditions will advance our fundamental knowledge about the brain and provide insight into the burden of sleep loss, with high relevance to many clinical populations. We and others have shown that sleep regulates synaptic communication between neurons in several brain regions. Moreover, excitatory and inhibitory synaptic transmission are regulated in opposite directions: excitation decreases and inhibition increases over sleep-rich periods. While these physiological changes are robust and replicable across laboratories, we do not yet know what plasticity mechanisms are responsible. In recent years, IT has become apparent that nanoscale-level organization of synaptic proteins is a key regulator of synaptic function and plasticity. However, assessing synaptic nanoarchitecture is challenging because conventional light microscopy does not have adequate resolution, and complements of synaptic proteins cannot be simultaneously visualized with electron microscopy. Here, we will use stimulated emission depletion (sted) nanoscopy to determine how sleep and sleep disruption shape synaptic nanoarchitecture of excitatory (aim 1) and inhibitory (aim 2) synapses. We will employ cutting-edge approaches that were recently developed and validated in our laboratory to visualize synaptic nanoarchitecture in mouse brain slice. We will determine how sleep alters the alignment and localization of proteins within the active zones and postsynaptic densities of excitatory and inhibitory synapses. We will examine synapses onto GFP-labeled pyramidal and parvalbumin neurons in layers 2/3 of the primary visual cortex, where synaptic transmission has been functionally characterized during sleep. These studies will reveal mechanisms by which sleep modifies synaptic function under typical conditions, laying the groundwork for future studies of how sleep loss impacts the brain in neurological conditions. These innovative high risk/high impact experiments are timely and have great potential to generate key breakthroughs in this important area of neuroscience.