Tunable somatosensory stimulation for selective sleep restriction studies in rodents

Many methods for sleep restriction in rodents have emerged, but most are intrusive, lack fine control, and induce stress. Therefore, a versatile, non-intrusive means of sleep restriction that can alter sleep in a controlled manner could be of great value in sleep research. In previous work, we proposed a novel system for closed-loop somatosensory stimulation based on mechanical vibration and applied it to the task of restricting Rapid Eye Movement (REM) sleep in mice [1]. While this system was effective, it was a crude prototype and did not allow precise control over the amplitude and frequency of stimulation applied to the animal. This paper details the progression of this system from a binary, 'all-or-none' version to one that allows dynamic control over perturbation to accomplish graded, state-dependent sleep restriction. Its preliminary use is described in two applications: deep sleep restriction in rats, and REM sleep restriction in mice.