Sleep loss and recovery after administration of drugs related to different arousal systems in rats

Abstract

Sleep is homeostatically regulated suggesting a restorative function. Sleep deprivation is compensated by an increase in length and intensity of sleep. In this study, suppression of sleep was induced pharmacologically by drugs related to different arousal systems. All drugs caused non-rapid eye movement (NREM) sleep loss followed by different compensatory processes. Apomorphine caused a strong suppression of sleep followed by an intense recovery. In the case of fluoxetine and eserine, recovery of NREM sleep was completed by the end of the light phase due to the biphasic pattern demonstrated for these drugs first in the present experiments. Yohimbine caused a long-lasting suppression of NREM sleep, indicating that either the noradrenergic system has the utmost strength among the examined systems, or that restorative functions occurring normally during NREM sleep were not blocked. Arousal systems are involved in the regulation of various wakefulness-related functions, such as locomotion and food intake. Therefore, it can be hypothesized that activation of the different systems results in qualitatively different waking states which might affect subsequent sleep differently. These differences might give some insight into the homeostatic function of sleep in which the dopaminergic and noradrenergic systems may play a more important role than previously suggested.

Complete sleep and local field potential analysis regarding estrus cycle, pregnancy, postpartum and post-weaning periods and homeostatic sleep regulation in female rats

“…This results in elevated NA levels during PRO when E2 level is high but according to the drop of E2 level during EST 26 , NA level may decrease in this period of the cycle. High NA level in the cortex is crucial to maintain desynchronized state 48 while during REM sleep, NA cells cease firing in the locus coeruleus 49 and high NA level in the cortex inhibit the expression of REM sleep as it can be seen after the application of the α 2 -adrenoceptor autoreceptor antagonist yohimbin 50 . Taken together, high NA level evoked by high E2 release cannot be appropriate for the presence of both W and REM sleep.…”

“…These objective thresholds were then used to score recordings obtained after the treatments. Epochs in which delta power was above and EMG value below these thresholds, respectively, were marked as SWS, while epochs with lower delta power or higher EMG activity as W. Scoring was performed by a semi-automated method had been published earlier 84 and was used in several studies published by our laboratory later 50,68,69,[85][86][87] . Raw hypnograms were smoothed, i.e.…”

Sleep- and sleep deprivation-related changes of vertex auditory evoked potentials during the estrus cycle in female rats

“…Epochs in which delta power was above and electromyographic activity value below these thresholds, respectively, were marked as SWS, while epochs with lower delta power or higher electromyographic activity as W. Scoring was performed by a semi-automated method that had been published earlier 89 using the slow wave content of the LFP as a main parameter for sleep scoring as delta power (˂ 4 Hz) is closely and inversely related to the level of cortical arousal 91 . The software and delta power based scoring method was used in several studies published by our laboratory 20 , 80 – 82 , 90 , 92 , 93 . Raw hypnograms were smoothed, i.e.…”

Assessing the Management of Excessive Daytime Sleepiness by Napping Benefits

“…In the case of the sleep homeostasis, this process consists in the drive for sleep that increases as a result to the prolonged waking time reaching a point that sleep pressure dissipates with the sleep onset. Thus, the sleep homeostasis mechanism exerts an adjustment after periods of prolonged waking by increasing the sleeping time, known as "sleep rebound" [19][20][21][22][23].…”

“…Then, the distance between both processes corresponds to the time when sleep normally is initiated. In sum, the interaction between Process C and Process S impacts the sleep-wake cycle and determines the importance of hourly patterns for prognosis, prevention and interventions for sleep disturbances, such as excessive sleepiness [19][20][21][22][23][24].…”