Not All Sleep Loss is Equal: A Comprehensive Evaluation of Rodent Models, Their Neurobiological Validity, and Translational Relevance to Neurological Disease

Not all sleep loss is the same, and failing to recognise this is the biggest barrier to advancing research in sleep and neurological diseases. This review systematically compares nine rodent sleep deprivation paradigms: gentle handling, the multiple platform method and its variants, the disk-over-water method, the Unpredictable Chronic Sleep Deprivation (UCSD) paradigm developed in our laboratory, novel object introduction, the curling prevention by water approach, automated mechanical systems, and the head-lifting method. It evaluates each for stress confound profile, sleep stage specificity, chronicity, and the neurobiological outcome domains to which it is appropriately suited. We describe the neuroimmune and neurochemical consequences of sleep loss across these models, covering hippocampal synaptic plasticity, prefrontal neurochemistry, glymphatic waste clearance, neuroinflammation, oxidative stress, hippocampal neurogenesis, and circadian clock gene regulation, and situate these findings within the translational context of Alzheimer's disease, Parkinson's disease, and neuropsychiatric comorbidities. Special attention is given to the UCSD paradigm, in which five established sleep disrupters, gentle handling, 24/0 h light/dark cycle, platform-over-water, crowded cage, and stroboscopic light, were applied in daily rotation without repetition across fourteen days. Using this paradigm, our group showed that chronic unpredictable sleep disruption, especially when combined with high-dose caffeine, causes prefrontal antioxidant depletion, serotonin loss, acetylcholinesterase upregulation, and synaptophysin reduction, confirmed through immunohistochemistry in Long-Evans rats, a neurochemical signature that aligns with early markers of neurodegeneration. We propose a disease-target-driven model selection framework, a six-priority translational research agenda, and minimum reporting standards for the field.