Nature and Science of Sleep (Oct 2022)
Validation of PiezoSleep Scoring Against EEG/EMG Sleep Scoring in Rats
Abstract
Irina Topchiy,1,2,* Anne M Fink,1,2 Katherine A Maki,2,3 Michael W Calik1,2,* 1Center for Sleep and Health Research, University of Illinois Chicago, Chicago, IL, USA; 2Department of Biobehavioral Nursing Science; University of Illinois Chicago, Chicago, IL, USA; 3Translational Biobehavioral and Health Disparities Branch, Clinical Center; National Institutes of Health, Bethesda, MD, USA*These authors contributed equally to this workCorrespondence: Michael W Calik, University of Illinois Chicago, 845 South Damen Avenue (M/C 802), College of Nursing, Room 740, Chicago, IL, 60612, USA, Tel +1 312 413 0581, Email [email protected]: Current methods of sleep research in rodents involve invasive surgical procedures of EEG and EMG electrodes implantation. Recently, a new method of measuring sleep, PiezoSleep, has been validated against implanted electrodes in mice and rats. PiezoSleep uses a piezoelectric film transducer to detect the rodent’s movements and respiration and employs an algorithm to automatically score sleep. Here, we validate PiezoSleep scoring versus EEG/EMG implanted electrodes sleep scoring in rats.Methods: Adult male Brown Norway and Wistar Kyoto rats were implanted with bilateral stainless-steel screws into the skull for EEG recording and bilateral wire electrodes into the nuchal muscles for EMG assessment. In Brown Norway rats, the EEG/EMG electrode leads were soldered to a miniature connector plug and fixed to the skull. In Wistar Kyoto rats, the EEG/EMG leads were tunneled subcutaneously to a telemetry transmitter implanted in the flank. Rats were allowed to recover from surgery for one week. Brown Norway rats were placed in PiezoSleep cages, and had their headsets connected to cable for recording EEG/EMG signals, which were then manually scored by a human scorer in 10-sec epochs. Wistar Kyoto rats were placed in PiezoSleep cages, and EEG/EMG signals were recorded using a telemetry system (DSI). Sleep was scored automatically in 4-sec epochs using NeuroScore software. PiezoSleep software recorded and scored sleep in the rats.Results: Rats implanted with corded EEG/EMG headsets had 85.6% concurrence of sleep-wake scoring with PiezoSleep. Rats implanted with EEG/EMG telemetry had 80.8% concurrence sleep-wake scoring with PiezoSleep. Sensitivity and specificity rates were similar between the EEG/EMG recording systems. Total sleep time and hourly sleep times did not differ in all three systems. However, automatic sleep detection by NeuroScore classified more sleep during the light period compared to the PiezoSleep.Conclusion: We showed that PiezoSleep system can be a reliable alternative to both automatic and visual EEG/EMG- based sleep-wake scoring in rat.Keywords: piezoelectric, noninvasive sleep scoring, telemetry, automated sleep scoring, EEG/EMG, rat
