JACUZI-SD: An automated, high-throughput, minimally stressful approach to sleep depriving larval zebrafish

Abstract While sleep deprivation broadly disrupts health and well-being, the neural and molecular mechanisms that signal increased sleep pressure remain poorly understood. A key obstacle to progress is the fact that traditional methods for inducing sleep deprivation (SD) in animal models often introduce confounding stress or disrupt circadian rhythms. Here, we present JACUZI-SD (Jetting Automated Currents Under Zebrafish to Induce Sleep Deprivation), a fully automated, high-throughput system designed to induce sleep deprivation in larval zebrafish with minimal stress. By delivering randomized water pulses via a custom milli-fluidic device integrated with a 96-well plate and controlled by an Arduino, JACUZI-SD promotes wakefulness during the natural dark cycle without the stress associated with existing SD methods. Our results demonstrate that JACUZI-SD reduces total sleep time by 41-64% and elicits a robust rebound sleep characterized by increased sleep bout length following deprivation. Importantly, this method avoids activating the hypothalamic-pituitary-interrenal (HPI) stress axis, as evidenced by reduced stress marker expression compared to other deprivation methods. Additionally, the system reliably activates established sleep pressure pathways, including the upregulation of galanin in the neurosecretory preoptic area, while also revealing biologically relevant inter-individual variability in homeostatic rebound responses. JACUZI-SD provides a powerful, minimally invasive platform for dissecting the neural and molecular underpinnings of sleep homeostasis in vertebrates. Competing Interest Statement S.B. is a co-founder and shareholder of CDI Labs, LLC, and receives support from Genentech. Footnotes New experimental data added to show: A.No rebound sleep and no induction of galanin in preoptic area following JACUZI-SD pulses applied during the first 6 hours of the light cycle and B.HPI activity levels following JACUZI-SD application during night phase. Schematic added to Figure 2. Individual measurements of efficiency of SD and sleep rebound added in Figure S5A. Changes to text throughout to improve clarity.