-
Proceedings of the National Academy of... Aug 2023Humans reason and care about ethical issues, such as avoiding unnecessary harm. But what enables us to develop a moral capacity? This question dates back at least to...
Humans reason and care about ethical issues, such as avoiding unnecessary harm. But what enables us to develop a moral capacity? This question dates back at least to ancient Greece and typically results in the traditional opposition between sentimentalism (the view that morality is mainly driven by socioaffective processes) and rationalism [the view that morality is mainly driven by (socio)cognitive processes or reason]. Here, we used multiple methods (eye-tracking and observations of expressive behaviors) to assess the role of both cognitive and socioaffective processes in infants' developing morality. We capitalized on the distinction between moral (e.g., harmful) and conventional (e.g., harmless) transgressions to investigate whether 18-mo-old infants understand actions as distinctively moral as opposed to merely disobedient or unexpected. All infants watched the same social scene, but based on prior verbal interactions, an actor's tearing apart of a picture (an act not intrinsically harmful) with a tool constituted either a conventional (wrong tool), a moral (producing harm), or no violation (correct tool). Infants' anticipatory looks differentiated between conventional and no violation conditions, suggesting that they processed the verbal interactions and built corresponding expectations. Importantly, infants showed a larger increase in pupil size (physiological arousal), and more expressions indicating empathic concern, in response to a moral than to a conventional violation. Thus, infants differentiated between harmful and harmless transgressions based solely on prior verbal interactions. Together, these convergent findings suggest that human infants' moral development is fostered by both sociocognitive (inferring harm) and socioaffective processes (empathic concern for others' welfare).
Topics: Humans; Infant; Morals; Moral Development; Wakefulness; Dissent and Disputes; Empathy
PubMed: 37487104
DOI: 10.1073/pnas.2306344120 -
The Lancet. Microbe Nov 2022
Topics: Wakefulness; Attention; Biological Science Disciplines
PubMed: 36334612
DOI: 10.1016/S2666-5247(22)00307-X -
Industrial Health Apr 2022Due to the unpredictable nature of working time arrangements, on-call workers experience regular disruption to sleep, particularly if woken by calls. Sleep disruption... (Review)
Review
Due to the unpredictable nature of working time arrangements, on-call workers experience regular disruption to sleep, particularly if woken by calls. Sleep disruption can impact long term physical and mental health, next day performance, and importantly, performance immediately after waking. To reduce the impact of performance impairments upon waking (i.e., reducing sleep inertia), research has investigated strategies to promote alertness (e.g., bright light, caffeine, and exercise). This review puts forth on-call workers who are likely to return to sleep after a call, it is also important to consider the impact of these sleep inertia countermeasures on subsequent sleep. Future research should build on the preliminary evidence base for sleep inertia countermeasures by examining the impact on subsequent sleep. This research is key for both supporting alertness and performance during a call ("switching on") and for allowing the on-call worker to return to sleep after a call ("switching off").
Topics: Attention; Cognition; Exercise; Humans; Sleep; Wakefulness
PubMed: 34690251
DOI: 10.2486/indhealth.2021-0124 -
The Journal of Neuroscience : the... Jun 2021The lateral hypothalamus (LH), together with multiple neuromodulatory systems of the brain, such as the dorsal raphe nucleus (DR), is implicated in arousal, yet...
The lateral hypothalamus (LH), together with multiple neuromodulatory systems of the brain, such as the dorsal raphe nucleus (DR), is implicated in arousal, yet interactions between these systems are just beginning to be explored. Using a combination of viral tracing, circuit mapping, electrophysiological recordings from identified neurons, and combinatorial optogenetics in mice, we show that GABAergic neurons in the LH selectively inhibit GABAergic neurons in the DR, resulting in increased firing of a substantial fraction of its neurons that ultimately promotes arousal. These DR neurons are wake active and project to multiple brain areas involved in the control of arousal, including the LH, where their specific activation potently influences local network activity leading to arousal from sleep. Our results show how mutual inhibitory projections between the LH and the DR promote wakefulness and suggest a complex arousal control by intimate interactions between long-range connections and local circuit dynamics. Multiple brain systems including the lateral hypothalamus and raphe serotonergic system are involved in the regulation of the sleep/wake cycle, yet the interaction between these systems have remained elusive. Here we show that mutual disinhibition mediated by long range inhibitory projections between these brain areas can promote wakefulness. The main importance of this work relies in revealing the interaction between a brain area involved in autonomic regulation and another in controlling higher brain functions including reward, patience, mood and sensory coding.
Topics: Animals; Dorsal Raphe Nucleus; GABAergic Neurons; Hypothalamic Area, Lateral; Male; Mice; Neural Pathways; Sleep; Wakefulness
PubMed: 33888606
DOI: 10.1523/JNEUROSCI.2850-20.2021 -
Neuroscience May 2016Over the last thirty years, a growing number of studies showed that astrocytes play a pivotal role in the energy support to synapses. More precisely, astrocytes adjust... (Review)
Review
Over the last thirty years, a growing number of studies showed that astrocytes play a pivotal role in the energy support to synapses. More precisely, astrocytes adjust energy production to neuronal energy needs through different mechanisms grouped under the term "neurometabolic coupling" (NMC). In this review we describe these mechanisms of coupling and how they involve astrocytes. From a physiological point of view, these mechanisms of coupling are particularly important to ensure normal synaptic functioning when neurons undergo rapid and repetitive changes in the firing rate such as during the sleep/wake transitions. Investigations into brain energy metabolism during the sleep/wake cycle have been mainly focused on glucose (Gluc) consumption and on glycogen metabolism. However, the recent development of substrate-specific biosensors allowed measurements of the variation in extracellular levels of glutamate, Gluc and lactate (Lac) with a time resolution compatible with sleep stage duration. Together with gene expression data these experiments allowed to better define the variations of energy metabolite regulation across the sleep/wake cycle. The aim of this review is to bring into perspective the role of astrocytes and NMC in the regulation of the sleep/wake cycle. The data reviewed also suggest an important role of the astrocytic network. In addition, the role of astrocytes in NMC mechanisms is consistent with the "local and use dependent" sleep hypothesis.
Topics: Animals; Astrocytes; Humans; Neurons; Sleep; Wakefulness
PubMed: 26704637
DOI: 10.1016/j.neuroscience.2015.12.007 -
Nature Communications Mar 2024Enhancement of wakefulness is a prerequisite for adaptive behaviors to cope with acute stress, but hyperarousal is associated with impaired behavioral performance....
Enhancement of wakefulness is a prerequisite for adaptive behaviors to cope with acute stress, but hyperarousal is associated with impaired behavioral performance. Although the neural circuitries promoting wakefulness in acute stress conditions have been extensively identified, less is known about the circuit mechanisms constraining wakefulness to prevent hyperarousal. Here, we found that chemogenetic or optogenetic activation of GAD2-positive GABAergic neurons in the midbrain dorsal raphe nucleus (DRN) decreased wakefulness, while inhibition or ablation of these neurons produced an increase in wakefulness along with hyperactivity. Surprisingly, DRN neurons were paradoxically wakefulness-active and were further activated by acute stress. Bidirectional manipulations revealed that DRN neurons constrained the increase of wakefulness and arousal level in a mouse model of stress. Circuit-specific investigations demonstrated that DRN neurons constrained wakefulness via inhibition of the wakefulness-promoting paraventricular thalamus. Therefore, the present study identified a wakefulness-constraining role DRN neurons in acute stress conditions.
Topics: Mice; Animals; Wakefulness; Dorsal Raphe Nucleus; Arousal; Mesencephalon; GABAergic Neurons
PubMed: 38548744
DOI: 10.1038/s41467-024-46707-9 -
Sleep Oct 2018The present study investigated the function of Hypocretin (Hcrt or Orexin/OX) receptor antagonists in sleep modulation and memory function with optical methods in...
STUDY OBJECTIVES
The present study investigated the function of Hypocretin (Hcrt or Orexin/OX) receptor antagonists in sleep modulation and memory function with optical methods in transgenic mice.
METHODS
We used Hcrt-IRES-Cre knock-in mice and AAV vectors expressing channelrhodopsin-2 (ChR2) to render Hcrt neurons sensitive to blue light stimulation. We optogenetically stimulated Hcrt neurons and measured latencies to wakefulness in the presence or absence of OX1/2R antagonists and Zolpidem. We also examined endogenous Hcrt neuronal activity with fiber photometry. Changes in memory after optogenetic sleep disruption were evaluated by the novel object recognition test (NOR) and compared for groups treated with vehicle, OX1/2R antagonists, or Zolpidem. We also analyzed electroencephalogram (EEG) power spectra of wakefulness, rapid eye movement (REM) sleep, and non-REM (NREM) sleep following the injections of vehicle, OX1/2R antagonists, and Zolpidem in young adult mice.
RESULTS
Acute optogenetic stimulation of Hcrt neurons at different frequencies resulted in wakefulness. Treatment with dual OX1/2R antagonists (DORAs) DORA12 and MK6096, as well as selective OX2R antagonist MK1064 and Zolpidem, but not selective OX1R antagonist 1SORA1, significantly reduced the bout length of optogenetic stimulation-evoked wakefulness episode. Fiber photometry recordings of GCaMP6f signals showed that Hcrt neurons are active during wakefulness, even in the presence of OXR antagonists. Treatment with dual OX1/2R antagonists improved memory function despite optogenetic sleep fragmentation caused impaired memory function in a NOR test.
CONCLUSIONS
Our results show DORAs and selective OX2R antagonists stabilize sleep and improve sleep-dependent cognitive processes even when challenged by optogenetic stimulation mimicking highly arousing stimuli.
Topics: Animals; Electroencephalography; Male; Memory; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neurons; Orexin Receptor Antagonists; Photic Stimulation; Sleep; Wakefulness; Zolpidem
PubMed: 30060151
DOI: 10.1093/sleep/zsy141 -
Clinical Autonomic Research : Official... Dec 2018Cardiovascular and respiratory parameters change during sleep and wakefulness. This observation underscores an important, albeit incompletely understood, role for the... (Review)
Review
Cardiovascular and respiratory parameters change during sleep and wakefulness. This observation underscores an important, albeit incompletely understood, role for the central nervous system in the differential regulation of autonomic functions. Understanding sleep/wake-dependent sympathetic modulations provides insights into diseases involving autonomic dysfunction. The purpose of this review was to define the central nervous system nuclei regulating sleep and cardiovascular function and to identify reciprocal networks that may underlie autonomic symptoms of disorders such as insomnia, sleep apnea, restless leg syndrome, rapid eye movement sleep behavior disorder, and narcolepsy/cataplexy. In this review, we examine the functional and anatomical significance of hypothalamic, pontine, and medullary networks on sleep, cardiovascular function, and breathing.
Topics: Autonomic Nervous System; Cardiovascular Physiological Phenomena; Cardiovascular System; Humans; Nervous System Diseases; Sleep; Sleep Wake Disorders; Wakefulness
PubMed: 30155794
DOI: 10.1007/s10286-018-0560-9 -
BMC Neuroscience Jan 2017Previous studies compared evoked potentials (EPs) between several sleep stages but only one uniform wake state. However, using electroencephalography (EEG), several...
BACKGROUND
Previous studies compared evoked potentials (EPs) between several sleep stages but only one uniform wake state. However, using electroencephalography (EEG), several arousal states can be distinguished before sleep onset. Recently, the Vigilance Algorithm Leipzig (VIGALL 2.0) has been developed, which automatically attributes one out of seven EEG-vigilance stages to each 1-s EEG segment, ranging from stage 0 (associated with cognitively active wakefulness), to stages A1, A2 and A3 (associated with relaxed wakefulness), to stages B1 and B2/3 (associated with drowsiness) up to stage C (indicating sleep onset). Applying VIGALL, we specified the effects of these finely differentiated EEG-vigilance stages (indicating arousal states) on EPs (P1, N1, P2, N300, MMN and P3) and behavioral performance. Subjects underwent an ignored and attended condition of a 2-h eyes-closed oddball-task. Final analysis included 43 subjects in the ignored and 51 subjects in the attended condition. First, the effect of brain arousal states on EPs and performance parameters were analyzed between EEG-vigilance stages A (i.e. A1, A2 and A3 combined), B1 and B2/3&C (i.e. B2/3 and C combined). Then, in a second step, the effects of the finely differentiated EEG-vigilance stages were further specified.
RESULTS
Comparing stages A versus B1 versus B2/3&C, a significant effect of EEG-vigilance stages on all behavioral parameters and all EPs, with exception of MMN and P3, was found. By applying VIGALL, a more detailed view of arousal effects on EP and performance was possible, such as the finding that the P2 showed no further significant increase in stages deeper than B1. Stage 0 did not differ from any of the A-stages. Within more fine-graded stages, such as the A-substages, EPs and performance only partially differed. However, these analyses were partly based on small sample sizes and future studies should take effort to get enough epochs of rare stages (such as A3 and C).
CONCLUSIONS
A clear impact of arousal on EPs and behavioral performance was obtained, which emphasize the necessity to consider arousal effects when interpreting EPs.
Topics: Adolescent; Adult; Algorithms; Attention; Cerebral Cortex; Electroencephalography; Evoked Potentials; Female; Humans; Male; Psychomotor Performance; Reaction Time; Signal Processing, Computer-Assisted; Wakefulness; Young Adult
PubMed: 28122495
DOI: 10.1186/s12868-017-0340-9 -
PLoS Computational Biology Oct 2022Paying attention to particular aspects of the world or being more vigilant in general can be interpreted as forms of 'internal' action. Such arousal-related choices come...
Paying attention to particular aspects of the world or being more vigilant in general can be interpreted as forms of 'internal' action. Such arousal-related choices come with the benefit of increasing the quality and situational appropriateness of information acquisition and processing, but incur potentially expensive energetic and opportunity costs. One implementational route for these choices is widespread ascending neuromodulation, including by acetylcholine (ACh). The key computational question that elective attention poses for sensory processing is when it is worthwhile paying these costs, and this includes consideration of whether sufficient information has yet been collected to justify the higher signal-to-noise ratio afforded by greater attention and, particularly if a change in attentional state is more expensive than its maintenance, when states of heightened attention ought to persist. We offer a partially observable Markov decision-process treatment of optional attention in a detection task, and use it to provide a qualitative model of the results of studies using modern techniques to measure and manipulate ACh in rodents performing a similar task.
Topics: Acetylcholine; Arousal; Wakefulness
PubMed: 36315594
DOI: 10.1371/journal.pcbi.1010642