Sleep-wake behavior of newborn rats recorded with movement sensitive method.

The aim of this study was to determine criteria for classification of sleep-wake behavior in newborn rats by recording total body and respiratory movements with a static charge sensitive bed (SCSB). Initially, the sleep-wake behavior was simultaneously observed visually and recorded by the SCSB mattress, from the fourth to the twenty-second postnatal days. Thus, the criteria for scoring the SCSB recordings were obtained by comparison of the behavioral scorings with the SCSB tracings. To further validate this movement sensitive method for neonatal sleep studies in rats, deep neck muscle electrograms were studied at the age range of 8-13 days, and electroencephalograms as well as electromyograms from the age of 12-17 days, simultaneously with the SCSB recordings. Finally, the sleep-wake behavior of other rat pups was recorded only with the SCSB from the fourth to the twenty-second postnatal days. These latter recordings were afterwards scored by using the criteria defined in the first part of this study. The results thus obtained indicate that the SCSB method is sensitive and reliable in recording and classifying the sleep-wake behavior of newborn rats.