GLUCOSE-REGULATED PROTEIN Grp78 AFFECTS CHARACTERISTICS OF SLEEP AND THERMOREGULATION IN RATS
Earlier it was shown that sleep deprivation in representatives of warm-blooded animals evokes an elevation of glucose-regulated protein 78 (Grp78) gene expression in the brain structures involved in the control of sleep and thermoregulation. However it is currently unknown what role the increased expression of Grp78 can play in the mechanisms that maintain homeostasis of sleep and thermoregulation. This study using electrophysiological methods has shown that the microinjections of Grp78 into the third brain ventricle of Wistar rats evoked an increase mostly in deep non-rapid-eye-movement (NREM) sleep (due to a lengthening of the duration of NREM sleep episodes) and a decrease in amount of rapid-eye-movement sleep. The period of deep NREM sleep was accompanied by reduced contractile muscular activity. Our results provide evidence that Grp78 participates in molecular mechanisms of maintenance of the deep NREM sleep accompanied by a decrease in contractile muscular activity which is typical for this state.