Somatic reflex response-reversal of reticular origin

Electroencephalogram (EEG) can be used to assess depth of consciousness, but interpreting EEG can be challenging, especially in neonates whose EEG undergo rapid changes during the perinatal course. EEG can be processed into quantitative EEG (QEEG), but limited data exist on the range of QEEG for normal term neonates during wakefulness and sleep, baseline information that would be useful to determine changes during sedation or anesthesia. We aimed to determine the range of QEEG in neonates during awake, active sleep and quiet sleep states, and identified the ones best at discriminating between the three states. Normal neonatal EEG from 37 to 46weeks were analyzed and classified as awake, quiet sleep, or active sleep. After processing and artifact removal, total power, power ratio, coherence, entropy, and spectral edge frequency (SEF) 50 and 90 were calculated. Descriptive statistics were used to summarize the QEEG in each of the three states. Receiver operating characteristic (ROC) curves were used to assess discriminatory ability of QEEG. 30 neonates were analyzed. QEEG were different between awake vs asleep states, but similar between active vs quiet sleep states. Entropy beta, delta2 power %, coherence delta2, and SEF50 were best at discriminating awake vs active sleep. Entropy beta had the highest AUC-ROC ≥ 0.84. Entropy beta, entropy delta1, theta power %, and SEF50 were best at discriminating awake vs quiet sleep. All had AUC-ROC ≥ 0.78. In active sleep vs quiet sleep, theta power % had highest AUC-ROC > 0.69, lower than the other comparisons. We determined the QEEG range in healthy neonates in different states of consciousness. Entropy beta and SEF50 were best at discriminating between awake and sleep states. QEEG were not as good at discriminating between quiet and active sleep. In the future, QEEG with high discriminatory power can be combined to further improve ability to differentiate between states of consciousness.

Brain stem somatic reflex activity in neonatal kittens during sleep and wakefulness

Hyperpolarizing membrane responses induced in lumbar motoneurons by stimulation of the nucleus reticularis pontis oralis during active sleep

Nonlinear dynamical analysis of the neonatal EEG time series: The relationship between sleep state and complexity

Hering-Breuer reflex and sleep state in the preterm infant.

Primary central alveolar hypoventilation (CAHV) is a rare disorder described in newborns, children, and adults. We report a 2 9/12 year old child with CAHV of unknown etiology. The evaluation of her ventilatory control system showed abnormalities awake and in the different sleep states. Hypoventilation was found to be more severe during non-REM sleep than during REM sleep and awake state. She had central apnea, an irregular respiratory rhythm in the non-REM sleep too, and diminished ventilatory response to inhaled 5%-6% CO2 in both REM and non-REM sleep. Her ventilation decreased when she was breathing 50% and 100% oxygen. During breathing 15% oxygen she did not arouse in spite a transcutaneous pO2 of 10 mmHg. She was first treated with mechanical ventilation during sleep and has now received bilateral simultaneous phrenic pacemaker support during quiet sleep for about one year. With the phrenic pacemaker she has normal minute volume and transcutaneous blood gases during sleep. During a respiratory infection she needed again mechanical ventilation via her tracheostoma 24 hours a day for one week. This case of a CAHV demonstrates a dysfunction of the central and partially also of the peripheral chemoreceptors. The abnormalities of the ventilation were demonstrable not only in the non-REM sleep but also in the REM sleep and awake state.

Electrophysiology of the frontal granular cortex. II. Patterns of spontaneous discharges of impulses of neurons in the cortex through states of sleep and wakefulness in the monkey

Patterns of fetal breathing in the baboon vary with EEG sleep state

Opioids are important for pain management but have the unwanted side effect of sleep disruption in humans ( Sleep Med Clin 13:271, 2018), rats ( Sci Rep 9:14122, 2019), and mice ( Neurosci Abstr Onlin e 502.02, 2019). Dose‐response data are needed for efforts to develop countermeasures to the undesired effects of opioids. Therefore, this study is testing the hypothesis that the sleep‐disrupting effects of opioids are dose dependent. Experiments were conducted in accordance with the FASEB Statement of Principles for the use of Animals in Research and Education. Adult male B6 mice (n=8) were housed in a temperature‐ and humidity‐controlled environment and 12:12h light:dark cycle. Mice were implanted with telemeters (DSI HD‐X02) to record cortical electroencephalogram (EEG) and neck muscle electromyogram. These measures made it possible to objectively quantify the effects of opioids on states of wakefulness, rapid eye movement (REM) sleep, and non‐REM (NREM) sleep. One week after recovery from surgery, each mouse began receiving subcutaneous injections (0.3 mL) within 60 min of light onset. States of sleep and wakefulness were recorded for 4 h after each injection. Repeated injections into the same mouse were separated by 3 or 4 days. Saline (vehicle control) was followed by increasing, half log doses (mg/kg) of morphine (0.01 to 30) or fentanyl (0.001 to 3). Every 10 s of each 4‐h recording was scored by two individuals, one of whom was blinded to the treatment condition. Sleep scoring concordance between the scorers was >90%. Data were analyzed using repeated measures ANOVA and Tukey's multiple comparisons test (GraphPad Prism V9). Morphine (F (8, 56) = 104.4, p <0.0001) and fentanyl (F (8, 56) = 94.65, p < 0.0001) dose‐dependently increased wakefulness, decreased NREM sleep (F (8, 56) = 110.2, p <0.0001; F (8, 56) = 96.30, p < 0.0001) and decreased REM sleep (F (8, 56) = 34.00, p <0.0001; F (8, 56) = 51.80, p <0.0001). The lowest dose of morphine that significantly increased wakefulness and decreased NREM sleep was 1 mg/kg (p = 0.04, p = 0.03); and 3 mg/kg for decreasing REM sleep (p = 0.0004). For fentanyl, the lowest dose that significantly increased wakefulness and decreased NREM and REM sleep was 0.3 mg/kg (p = 0.001; p = 0.0016; p = 0.0007). Higher doses of morphine and fentanyl eliminated NREM and REM sleep. Both opioids also significantly and differentially altered EEG power during wakefulness (see companion abstract by O’Brien et al.). Nonlinear regression was used to calculate the half‐maximal dose (mg/kg) for increasing wakefulness (ED 50 ) and inhibiting sleep (ID 50 ). ED 50 and ID 50 data were used to compare drug potency. Morphine ED 50 was 2.2 to increase wakefulness, ID 50 2.3 to decrease NREM sleep, and 1.3 to decrease REM sleep. Fentanyl ED 50 was 0.2 to increase wakefulness, ID 50 0.2 to decrease NREM sleep, and 0.1 to decrease REM sleep. These data demonstrate that opioid‐induced sleep disruption is dose‐dependent, and that fentanyl is more potent than morphine to disrupt sleep.

Understanding the detection of salient auditory stimuli by the deep layer of the superior colliculus (dSC) during REM and NREM sleep offers valuable insights into the neurophysiological mechanisms of state-dependent auditory information processing. We recorded local field potentials (LFP) from dSC, electrocorticogram (ECoG) from frontal/parietal cortical regions, and neck electromyogram (EMG) in freely moving rats during sleep and awake states under oddball paradigm auditory stimulations. Our analysis focused on mismatch negativity (MMN) responses and event-related spectral perturbation (ERSP) in slow gamma (30-60 Hz) activity (SGA) and medium gamma (60-95 Hz) activity (MGA) frequency bands in wakefulness, REM and NREM sleep using three different intensities (35-, 55-, 80-dB) of stimulation. Data were analysed using repeated-measure two-way ANOVA and Linear Mixed Model. We found that the dSC exhibited significantly increased MMN responses to salient auditory stimuli across nearly all conditions (p < 0.05), specifically in REM, compared to other vigilance states. Additionally, stimulus intensity in pure tone experiments significantly enhances the MMN peak amplitude (p < 0.0001). The dSC further illustrated state-dependent spectral dynamics: SGA (30-60 Hz) ERSP substantially increased in NREM (p < 0.0001), while MGA (60-95 Hz) ERSP increased in both REM/NREM significantly (p < 0.001). These findings demonstrate that the dSC, a key node within the auditory processing network, retains robust auditory salience detection in sleep states.

Epoch lengths from 20 seconds to 1 minute, and smoothing strategies from zero to three minutes are encountered in the infant sleep and waking literature. The present study systematically examined the impact of various epoch lengths and smoothing strategies on infant sleep state architecture. Overnight polysomnographic recordings were visually assessed by epoch as wake or as each of four sleep state parameters: electroencephalographic patterns, respiration, body movement, and eye movement. From these findings, sleep and waking states were assigned for each of six combinations of epoch length (30-second or 1-minute) and smoothing window length (none, 3-epoch, or 5-epoch). N/A. Subjects were 91 term infants, 42-46 weeks postconceptional age, from the Collaborative Home Infant Monitoring Evaluation (CHIME) study. N/A. A greater epoch length resulted in more active and less quiet sleep as a percentage of total study; however, the size of the smoothing window did not affect the percentage of sleep/waking states. In general, the greater the epoch length and the greater the smoothing window length, the fewer the number of, the greater the mean duration of, and the greater the longest continuous episode of sleep/waking states. Analysis of significant interactions indicated that a 1-minute epoch length relative to a 30-second epoch length resulted in increasingly longer episodes of quiet and especially active sleep with a greater smoothing window length. Smoothing strategy significantly altered sleep state architecture in infants and may explain part of the variability in infant sleep state findings between laboratories.

Switches between global sleep and wakefulness states are believed to be dictated by top-down influences arising from subcortical nuclei. Using forward genetics and in vivo electrophysiology, we identified a recessive mouse mutant line characterized by a substantially reduced propensity to transition between wake and sleep states with an especially pronounced deficit in initiating rapid eye movement (REM) sleep episodes. The causative mutation, an Ile102Asn substitution in the synaptic vesicular protein, VAMP2, was associated with morphological synaptic changes and specific behavioral deficits, while in vitro electrophysiological investigations with fluorescence imaging revealed a markedly diminished probability of vesicular release in mutants. Our data show that global shifts in the synaptic efficiency across brain-wide networks leads to an altered probability of vigilance state transitions, possibly as a result of an altered excitability balance within local circuits controlling sleep-wake architecture.

Foreword

Respiratory frequency during sleep in siblings of sudden infant death syndrome victims. a comparison with control, normal infants

Prolongation of the Q-T interval in man during sleep