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1.
J Ethnopharmacol ; 328: 117974, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38467317

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Acute alcohol intoxication is one of the leading causes of coma. A well-regarded Chinese herbal formula, known as An-Gong-Niu-Huang-Wan (AGNHW), has garnered recognition for its efficacy in treating various brain disorders associated with impaired consciousness, including acute alcohol-induced coma. Despite its clinical effectiveness, the scientific community lacks comprehensive research on the mechanistic aspects of AGNHW's impact on the electroencephalogram (EEG) patterns observed during alcohol-induced coma. Gaining a deeper understanding of AGNHW's mechanism of action in relation to EEG characteristics would hold immense importance, serving as a solid foundation for further advancing its clinical therapeutic application. AIM OF THE STUDY: The study sought to investigate the impact of AGNHW on EEG activity and sleep EEG patterns in rats with alcoholic-induced coma. MATERIALS AND METHODS: A rat model of alcohol-induced coma was used to examine the effects of AGNHW on EEG patterns. Male Sprague-Dawley rats were intraperitoneally injected with 32% ethanol to induce a coma, followed by treatment with AGNHW. Wireless electrodes were implanted in the cortex of the rats to obtain EEG signals. Our analysis focused on evaluating alterations in the Rat Coma Scale (RCS), as well as assessing changes in the frequency and distribution of EEG patterns, sleep rhythms, and body temperature subsequent to AGNHW treatment. RESULTS: The study found a significant increase in the δ-band power ratio, as well as a decrease in RCS scores and ß-band power ratio after modeling. AGNHW treatment significantly reduced the δ-band power ratio and increased the ß-band power ratio compared to naloxone, suggesting its superior arousal effects. The results also revealed a decrease in the time proportion of WAKE and REM EEG patterns after modeling, accompanied by a significant increase in the time proportion of NREM EEG patterns. Both naloxone and AGNHW effectively counteracted the disordered sleep EEG patterns. Additionally, AGNHW was more effective than naloxone in improving hypothermia caused by acute alcohol poisoning in rats. CONCLUSION: Our study provides evidence for the arousal effects of AGNHW in alcohol-induced coma rats. It also suggests a potential role for AGNHW in regulating post-comatose sleep rhythm disorders.


Subject(s)
Alcoholic Intoxication , Coma , Rats , Male , Animals , Rats, Sprague-Dawley , Coma/chemically induced , Coma/drug therapy , Electroencephalography , Arousal/physiology , Sleep , Naloxone/pharmacology
2.
Sci Rep ; 14(1): 5197, 2024 03 02.
Article in English | MEDLINE | ID: mdl-38431722

ABSTRACT

Athletes need to achieve their optimal level of arousal for peak performance. Visualization or mental rehearsal (i.e., Imagery) often helps to obtain an appropriate level of activation, which can be detected by monitoring Skin Conductance Level (SCL). However, different types of imagery could elicit different amount of physiological arousal. Therefore, this study aims: (1) to investigate differences in SCL associated with two instructional modalities of imagery (guided vs. self-produced) and six different scripts; (2) to check if SCL could differentiate respondents according to their sport expertise. Thirty participants, aged between 14 and 42 years (M = 22.93; SD = 5.24), with different sport levels took part in the study. Participants listened to each previously recorded script and then were asked to imagine the scene for a minute. During the task, SCL was monitored. We analysed the mean value, variance, slope and number of fluctuations per minute of the electrodermal signal. Unsupervised machine learning models were used for measuring the resemblance of the signal. The Wilcoxon signed-rank test was used for distinguishing guided and self-produced imagery, and The Mann-Whitney U test was used for distinguishing results of different level athletes. We discovered that among others, self-produced imagery generates lower SCL, higher variance, and a higher number of fluctuations compared to guided imagery. Moreover, we found similarities of the SCL signal among the groups of athletes (i.e. expertise level). From a practical point of view, our findings suggest that different imagery instructional modalities can be implemented for specific purposes of mental preparation.


Subject(s)
Imagery, Psychotherapy , Sports , Humans , Adolescent , Young Adult , Adult , Galvanic Skin Response , Arousal/physiology , Athletes
3.
Sci Rep ; 14(1): 2950, 2024 02 05.
Article in English | MEDLINE | ID: mdl-38316863

ABSTRACT

After severe brain injury, zolpidem is known to cause spectacular, often short-lived, restorations of brain functions in a small subgroup of patients. Previously, we showed that these zolpidem-induced neurological recoveries can be paralleled by significant changes in functional connectivity throughout the brain. Deep brain stimulation (DBS) is a neurosurgical intervention known to modulate functional connectivity in a wide variety of neurological disorders. In this study, we used DBS to restore arousal and motivation in a zolpidem-responsive patient with severe brain injury and a concomitant disorder of diminished motivation, more than 10 years after surviving hypoxic ischemia. We found that DBS of the central thalamus, targeted at the centromedian-parafascicular complex, immediately restored arousal and was able to transition the patient from a state of deep sleep to full wakefulness. Moreover, DBS was associated with temporary restoration of communication and ability to walk and eat in an otherwise wheelchair-bound and mute patient. With the use of magnetoencephalography (MEG), we revealed that DBS was generally associated with a marked decrease in aberrantly high levels of functional connectivity throughout the brain, mimicking the effects of zolpidem. These results imply that 'pathological hyperconnectivity' after severe brain injury can be associated with reduced arousal and behavioral performance and that DBS is able to modulate connectivity towards a 'healthier baseline' with lower synchronization, and, can restore functional brain networks long after severe brain injury. The presence of hyperconnectivity after brain injury may be a possible future marker for a patient's responsiveness for restorative interventions, such as DBS, and suggests that lower degrees of overall brain synchronization may be conducive to cognition and behavioral responsiveness.


Subject(s)
Akinetic Mutism , Brain Injuries , Deep Brain Stimulation , Humans , Deep Brain Stimulation/methods , Zolpidem , Motivation , Thalamus/physiology , Arousal/physiology
4.
Eur J Neurosci ; 59(4): 570-583, 2024 Feb.
Article in English | MEDLINE | ID: mdl-36889675

ABSTRACT

The interruption of sleep by a nociceptive stimulus is favoured by an increase in the pre-stimulus functional connectivity between sensory and higher level cortical areas. In addition, stimuli inducing arousal also trigger a widespread electroencephalographic (EEG) response reflecting the coordinated activation of a large cortical network. Because functional connectivity between distant cortical areas is thought to be underpinned by trans-thalamic connections involving associative thalamic nuclei, we investigated the possible involvement of one principal associative thalamic nucleus, the medial pulvinar (PuM), in the sleeper's responsiveness to nociceptive stimuli. Intra-cortical and intra-thalamic signals were analysed in 440 intracranial electroencephalographic (iEEG) segments during nocturnal sleep in eight epileptic patients receiving laser nociceptive stimuli. The spectral coherence between the PuM and 10 cortical regions grouped in networks was computed during 5 s before and 1 s after the nociceptive stimulus and contrasted according to the presence or absence of an arousal EEG response. Pre- and post-stimulus phase coherence between the PuM and all cortical networks was significantly increased in instances of arousal, both during N2 and paradoxical (rapid eye movement [REM]) sleep. Thalamo-cortical enhancement in coherence involved both sensory and higher level cortical networks and predominated in the pre-stimulus period. The association between pre-stimulus widespread increase in thalamo-cortical coherence and subsequent arousal suggests that the probability of sleep interruption by a noxious stimulus increases when it occurs during phases of enhanced trans-thalamic transfer of information between cortical areas.


Subject(s)
Pulvinar , Humans , Sleep , Arousal/physiology , Electroencephalography , Thalamus/physiology
5.
J Sleep Res ; 33(2): e14003, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37688512

ABSTRACT

Nightmares are common among the general population and psychiatric patients and have been associated with signs of nocturnal arousal such as increased heart rate or increased high-frequency electroencephalographic (EEG) activity. However, it is still unclear, whether these characteristics are more of a trait occurring in people with frequent nightmares or rather indicators of the nightmare state. We compared participants with frequent nightmares (NM group; n = 30) and healthy controls (controls; n = 27) who spent 4 nights in the sleep laboratory over the course of 8 weeks. The NM group received six sessions of imagery rehearsal therapy (IRT), the 'gold standard' of cognitive-behavioural therapy for nightmares, between the second and the third night. Sleep architecture and spectral power were compared between groups, and between nights of nightmare occurrence and nights without nightmare occurrence in the NM group. Additionally, changes before and after therapy were recorded. The NM group showed increased beta (16.25-31 Hz) and low gamma (31.25-35 Hz) power during the entire night compared to the controls, but not when comparing nights of nightmare occurrence to those without. Moreover, low gamma activity in rapid eye movement sleep was reduced after therapy in the NM group. Our findings indicate, cortical hyperarousal is more of a trait in people with frequent nightmares within a network of other symptoms, but also malleable by therapy. This is not only a new finding for IRT but could also lead to improved treatment options in the future that directly target high-frequency EEG activity.


Subject(s)
Dreams , Stress Disorders, Post-Traumatic , Humans , Dreams/physiology , Sleep , Sleep, REM/physiology , Arousal/physiology , Electroencephalography
6.
Nat Hum Behav ; 8(1): 43-62, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37904022

ABSTRACT

The brain's arousal state is controlled by several neuromodulatory nuclei known to substantially influence cognition and mental well-being. Here we investigate whether human participants can gain volitional control of their arousal state using a pupil-based biofeedback approach. Our approach inverts a mechanism suggested by previous literature that links activity of the locus coeruleus, one of the key regulators of central arousal and pupil dynamics. We show that pupil-based biofeedback enables participants to acquire volitional control of pupil size. Applying pupil self-regulation systematically modulates activity of the locus coeruleus and other brainstem structures involved in arousal control. Furthermore, it modulates cardiovascular measures such as heart rate, and behavioural and psychophysiological responses during an oddball task. We provide evidence that pupil-based biofeedback makes the brain's arousal system accessible to volitional control, a finding that has tremendous potential for translation to behavioural and clinical applications across various domains, including stress-related and anxiety disorders.


Subject(s)
Arousal , Pupil , Humans , Pupil/physiology , Arousal/physiology , Locus Coeruleus/physiology , Cognition/physiology , Biofeedback, Psychology
7.
PLoS One ; 18(12): e0294629, 2023.
Article in English | MEDLINE | ID: mdl-38085715

ABSTRACT

Emotional prospective mental imagery, in which we simulate possible future events within our minds, have a pronounced impact on behavior. For example, repeated engagement in positive prospective imagery can lead to behavioral activation, while negative prospective imagery can lead to catastrophizing and avoidance. Physiological arousal boosts memory consolidation, creating emotional memories. Thus, if emotional prospective imagery produces an arousal response, the memory consolidation of these simulations of the future may be boosted, offering a possible underlying mechanism for the impact of emotional prospective imagery on behavior. In order to examine the feasibility of arousal as a possible mechanism behind the impact of emotional prospective imagery on behavior, sixty participants produced autobiographical prospective imagery of 30 scenes (10 positive, 10 neutral, and 10 negative), during which arousal responses (skin conductance) were measured, and ratings for subjective arousal, valence, and imagery vividness were collected. Moreover, because vividness of prospective imagery has been related to anxiety and depression, the study examined this relation also for event-related autobiographical prospective imagery. The results showed that emotional prospective imagery were associated with higher subjective arousal ratings as compared to neutral imagery. Physiological arousal responses showed a similar pattern, but further data is needed for a firm conclusion. Nevertheless, arousal-boosted consolidation remains a possible contributing mechanism for the impact of emotional prospective imagery on behavior. Moreover, results suggest both anxiety and depression may entail a reduced ability to invent prospective life situations. However, only anxiety was associated with less vivid imaginations, unless the imaginations were of negative content. Hence, anxious individuals may experience negative prospective imagery more vividly than imagery with neutral and positive content.


Subject(s)
Anxiety , Emotions , Humans , Emotions/physiology , Anxiety/psychology , Imagery, Psychotherapy , Imagination/physiology , Arousal/physiology
8.
Nat Commun ; 14(1): 6381, 2023 10 11.
Article in English | MEDLINE | ID: mdl-37821426

ABSTRACT

Circadian clocks generate rhythms of arousal, but the underlying molecular and cellular mechanisms remain unclear. In Drosophila, the clock output molecule WIDE AWAKE (WAKE) labels rhythmic neural networks and cyclically regulates sleep and arousal. Here, we show, in a male mouse model, that mWAKE/ANKFN1 labels a subpopulation of dorsomedial hypothalamus (DMH) neurons involved in rhythmic arousal and acts in the DMH to reduce arousal at night. In vivo Ca2+ imaging reveals elevated DMHmWAKE activity during wakefulness and rapid eye movement (REM) sleep, while patch-clamp recordings show that DMHmWAKE neurons fire more frequently at night. Chemogenetic manipulations demonstrate that DMHmWAKE neurons are necessary and sufficient for arousal. Single-cell profiling coupled with optogenetic activation experiments suggest that GABAergic DMHmWAKE neurons promote arousal. Surprisingly, our data suggest that mWAKE acts as a clock-dependent brake on arousal during the night, when mice are normally active. mWAKE levels peak at night under clock control, and loss of mWAKE leads to hyperarousal and greater DMHmWAKE neuronal excitability specifically at night. These results suggest that the clock does not solely promote arousal during an animal's active period, but instead uses opposing processes to produce appropriate levels of arousal in a time-dependent manner.


Subject(s)
Circadian Clocks , Sleep , Mice , Animals , Male , Arousal/physiology , Neurons/physiology , Hypothalamus/physiology , Circadian Rhythm/physiology
9.
J Neurosci ; 43(46): 7812-7821, 2023 11 15.
Article in English | MEDLINE | ID: mdl-37758474

ABSTRACT

In human and nonhuman primates, deep brain stimulation applied at or near the internal medullary lamina of the thalamus [a region referred to as "central thalamus," (CT)], but not at nearby thalamic sites, elicits major changes in the level of consciousness, even in some minimally conscious brain-damaged patients. The mechanisms behind these effects remain mysterious, as the connections of CT had not been specifically mapped in primates. In marmoset monkeys (Callithrix jacchus) of both sexes, we labeled the axons originating from each of the various CT neuronal populations and analyzed their arborization patterns in the cerebral cortex and striatum. We report that, together, these CT populations innervate an array of high-level frontal, posterior parietal, and cingulate cortical areas. Some populations simultaneously target the frontal, parietal, and cingulate cortices, while others predominantly target the dorsal striatum. Our data indicate that CT stimulation can simultaneously engage a heterogeneous set of projection systems that, together, target the key nodes of the attention, executive control, and working-memory networks of the brain. Increased functional connectivity in these networks has been previously described as a signature of consciousness.SIGNIFICANCE STATEMENT In human and nonhuman primates, deep brain stimulation at a specific site near the internal medullary lamina of the thalamus ["central thalamus," (CT)] had been shown to restore arousal and awareness in anesthetized animals, as well as in some brain-damaged patients. The mechanisms behind these effects remain mysterious, as CT connections remain poorly defined in primates. In marmoset monkeys, we mapped with sensitive axon-labeling methods the pathways originated from CT. Our data indicate that stimulation applied in CT can simultaneously engage a heterogeneous set of projection systems that, together, target several key nodes of the attention, executive control, and working-memory networks of the brain. Increased functional connectivity in these networks has been previously described as a signature of consciousness.


Subject(s)
Brain Injuries , Callithrix , Male , Animals , Female , Humans , Thalamus/physiology , Cerebral Cortex/physiology , Arousal/physiology , Consciousness/physiology , Neural Pathways/physiology
10.
Conscious Cogn ; 115: 103569, 2023 10.
Article in English | MEDLINE | ID: mdl-37660419

ABSTRACT

This study examined whether and how emotional hypnotic suggestions modulate the visual recognition of negative words. We investigated the influence of hypnotic suggestions aimed at modifying emotional reactivity on the arousal effect in negative words. High and low suggestible individuals performed a go/no-go lexical decision task in three intra-individual conditions: with a suggestion to increase emotional reactivity, with a suggestion to decrease emotional reactivity and without hypnotic suggestion. Results showed that hypnotic suggestions modulated the arousal facilitation effect differently depending on the level of suggestibility of the participants. In high suggestible individuals, response times for low-arousal negative words varied oppositely according to the suggestion administered, while no modulations were retrieved for high-arousal ones. In contrast, no suggestion effects were found for low suggestible participants. Altogether, these findings suggest a higher influence of hypnotic suggestions on emotional words that require longer processing times in high suggestible individuals.


Subject(s)
Hypnosis , Humans , Suggestion , Arousal/physiology , Recognition, Psychology , Reaction Time
11.
Clin Psychol Psychother ; 30(6): 1256-1263, 2023.
Article in English | MEDLINE | ID: mdl-37565308

ABSTRACT

INTRODUCTION: This work aims to demonstrate, through the International Affective Picture System (IAPS) responses, an altered emotional pattern in borderline personality disorder (BPD) patients and to find a specific emotional response pattern by understanding their relationship with traumatic experiences and attachment bonds towards their primary caregivers. METHOD: A total of 50 BPD patients and 39 control patients were evaluated using the IAPS, and its assessment was carried out through the Self-Assessment Manikin (SAM). Paternal and maternal attachment bonds as well as traumatic experiences in BPD patients were evaluated. Statistical associations were analysed in the different variables. RESULTS: Significant differences between BPD and control patients were found in all emotional response components for pleasant, unpleasant and neutral images (p < .01), with one exception, the arousal in pleasant images. Patients' experience of traumatic experiences was positively related to scores on the happiness component of pleasant imagery (p = .057) and on the arousal component of unpleasant imagery (p = .058). Poorer maternal bonding in BPD patients was significantly related to lower scores on happiness (p < .01) and dominance (p < .05) components of pleasant imagery and all emotional response components for unpleasant imagery (p < .01). CONCLUSIONS: The results of the study confirm an impaired emotional response pattern in patients with borderline personality disorder (BPD), showing an emotional response to pleasant images similar to that of depression, while the pattern found to unpleasant images could be related to the complex trauma observed in these patients, which includes PTSD experiences such as sexual abuse and attachment trauma experiences.


Subject(s)
Borderline Personality Disorder , Male , Humans , Borderline Personality Disorder/complications , Borderline Personality Disorder/psychology , Emotions/physiology , Arousal/physiology , Self-Assessment , Happiness
12.
Neuron ; 111(20): 3270-3287.e8, 2023 10 18.
Article in English | MEDLINE | ID: mdl-37557180

ABSTRACT

The expression of defensive responses to alerting sensory cues requires both general arousal and a specific arousal state associated with defensive emotions. However, it remains unclear whether these two forms of arousal can be regulated by common brain regions. We discovered that the medial sector of the auditory thalamus (ATm) in mice is a thalamic hub controlling both general and defensive arousal. The spontaneous activity of VGluT2-expressing ATm (ATmVGluT2+) neurons was correlated with and causally contributed to wakefulness. In sleeping mice, sustained ATmVGluT2+ population responses were predictive of sensory-induced arousal, the likelihood of which was markedly decreased by inhibiting ATmVGluT2+ neurons or multiple downstream pathways. In awake mice, ATmVGluT2+ activation led to heightened arousal accompanied by excessive anxiety and avoidance behavior. Notably, blocking their neurotransmission abolished alerting stimuli-induced defensive behaviors. These findings may shed light on the comorbidity of sleep disturbances and abnormal sensory sensitivity in specific brain disorders.


Subject(s)
Arousal , Thalamus , Mice , Animals , Arousal/physiology , Thalamus/physiology , Wakefulness/physiology , Neurons/physiology , Synaptic Transmission
13.
Sci Rep ; 13(1): 12399, 2023 08 08.
Article in English | MEDLINE | ID: mdl-37553409

ABSTRACT

Inspired by advances in wearable technologies, we design and perform human-subject experiments. We aim to investigate the effects of applying safe actuation (i.e., auditory, gustatory, and olfactory) for the purpose of regulating cognitive arousal and enhancing the performance states. In two proposed experiments, subjects are asked to perform a working memory experiment called n-back tasks. Next, we incorporate listening to different types of music, drinking coffee, and smelling perfume as safe actuators. We employ signal processing methods to seamlessly infer participants' brain cognitive states. The results demonstrate the effectiveness of the proposed safe actuation in regulating the arousal state and enhancing performance levels. Employing only wearable devices for human monitoring and using safe actuation intervention are the key components of the proposed experiments. Our dataset fills the existing gap of the lack of publicly available datasets for the self-management of internal brain states using wearable devices and safe everyday actuators. This dataset enables further machine learning and system identification investigations to facilitate future smart work environments. This would lead us to the ultimate idea of developing practical automated personalized closed-loop architectures for managing internal brain states and enhancing the quality of life.


Subject(s)
Acoustic Stimulation , Brain , Cognition , Memory, Short-Term , Smell , Taste , Wearable Electronic Devices , Female , Humans , Male , Arousal/physiology , Brain/physiology , Coffee , Cognition/physiology , Datasets as Topic , Memory, Short-Term/physiology , Music , Perfume , Pilot Projects , Quality of Life , Smell/physiology , Taste/physiology , Adult , Electroencephalography
14.
Arch Sex Behav ; 52(5): 2249-2260, 2023 07.
Article in English | MEDLINE | ID: mdl-37253921

ABSTRACT

Persistent genital arousal disorder/genitopelvic dysesthesia (PGAD/GPD) is characterized by persistent, unwanted physiological genital arousal (i.e., sensitivity, fullness, and/or swelling) in the absence of sexual excitement or desire which can persist for hours to days and causes significant impairment in psychosocial well-being (e.g., distress) and daily functioning. The etiology and course of PGAD/GPD is still relatively unknown and, unsurprisingly, there are not yet clear evidence-based treatment recommendations for those suffering from PGAD/GPD. We present the case of a 58-year-old woman with acquired persistent genital arousal disorder, which began in March 2020; she believed she developed PGAD/GPD due to a period of significant distress and anxiety related to the COVID-19 pandemic. After seeking medical diagnosis and treatment from multiple healthcare providers and trying a combination of pharmacological and medical treatment modalities, she presented for psychological treatment. An integrative therapy approach (3 assessment sessions, 11 treatment sessions), which included cognitive behavior therapy, distress tolerance and emotion regulation skills from dialectical behavior therapy, and mindfulness practice, was utilized. The patient reported improvements anecdotally (e.g., decreased impact on occupational and social functioning, greater self-compassion, less frequent and shorter duration of PGAD/GPD flare-ups, improved ability to cope with PGAD/GPD symptoms, and decreased need for sleeping medication) and on self-report measures (e.g., lower PGAD/GPD catastrophizing, lower anxiety and depression, and greater overall quality of life).We report the use of an integrative (i.e., psychoeducational, cognitive behavioral, dialectical behavioral, and mindfulness-based) intervention, which may be an effective psychological treatment for PGAD/GPD.


Subject(s)
COVID-19 , Sexual Dysfunctions, Psychological , Female , Humans , Middle Aged , Sexual Dysfunctions, Psychological/therapy , Sexual Dysfunctions, Psychological/diagnosis , Paresthesia/complications , Quality of Life , Pandemics , Arousal/physiology , Genitalia
15.
Sci Rep ; 13(1): 2628, 2023 02 14.
Article in English | MEDLINE | ID: mdl-36788344

ABSTRACT

Imagery is a well-known technique in mental training which improves performance efficiency and influences physiological arousal. One of the biomarkers indicating the amount of physiological arousal is skin conductance level (SCL). The aim of our study is to understand how individual differences in personality (e.g. neuroticism), general imagery and situational sport anxiety are linked to arousal measuring with SCL in situational imagery. Thirty participants aged between 14 and 42 years (M = 22.93; SD = 5.24), with sport experience ranging between 2 and 20 years (M = 10.15; SD = 4.75), took part in our study. Participants listened to each previously recorded script and then were asked to imagine the scene for a minute. During the task SCL was monitored using the Biofeedback Expert 2000. Machine learning predictive models based on artificial neural networks have been trained for prediction of physiological response, as a function of selected psychological tests. We found an association among neuroticism, prestart anxiety, and general tendency to use imagery with SCL. From a practical point of view our results may help athletes, coaches, and psychologists to be more aware of the role of individual differences in sport.


Subject(s)
Sports , Humans , Adolescent , Young Adult , Adult , Sports/psychology , Imagery, Psychotherapy , Arousal/physiology , Psychological Tests , Athletes
16.
Curr Biol ; 33(5): 875-885.e5, 2023 03 13.
Article in English | MEDLINE | ID: mdl-36754050

ABSTRACT

Auditory-induced arousal is a defense mechanism of animals against potential dangers. Although the thalamus is the neural substrate that relays sensory information to the cortex, its function is reduced during slow-wave sleep (SWS), also known as deep sleep. Despite this, animals are capable of waking up in response to external sensory stimuli, suggesting the existence of neural circuits that are involved in this response. Here, we report that kainate-class-type ionotropic glutamate receptor subunit 4 (GRIK4)-positive mediodorsal (MD) thalamic neurons act as a neural substrate for arousals from SWS. These neurons become active during arousal from SWS and their photoactivation can induce arousal from SWS. Moreover, we show that these neurons are influenced by glutamatergic neurons in the brainstem, the activity of which increases during auditory-induced arousals. These results suggest that this brainstem-MD pathway can mediate wakefulness from SWS.


Subject(s)
Sleep, Slow-Wave , Sleep , Animals , Sleep/physiology , Arousal/physiology , Thalamus/physiology , Wakefulness/physiology , Brain Stem
17.
Nat Commun ; 13(1): 5442, 2022 09 16.
Article in English | MEDLINE | ID: mdl-36114170

ABSTRACT

Awakening from sleep reflects a profound transformation in neural activity and behavior. The thalamus is a key controller of arousal state, but whether its diverse nuclei exhibit coordinated or distinct activity at transitions in behavioral arousal state is unknown. Using fast fMRI at ultra-high field (7 Tesla), we measured sub-second activity across thalamocortical networks and within nine thalamic nuclei to delineate these dynamics during spontaneous transitions in behavioral arousal state. We discovered a stereotyped sequence of activity across thalamic nuclei and cingulate cortex that preceded behavioral arousal after a period of inactivity, followed by widespread deactivation. These thalamic dynamics were linked to whether participants subsequently fell back into unresponsiveness, with unified thalamic activation reflecting maintenance of behavior. These results provide an outline of the complex interactions across thalamocortical circuits that orchestrate behavioral arousal state transitions, and additionally, demonstrate that fast fMRI can resolve sub-second subcortical dynamics in the human brain.


Subject(s)
Arousal , Thalamus , Arousal/physiology , Brain/diagnostic imaging , Humans , Sleep , Thalamic Nuclei/diagnostic imaging , Thalamic Nuclei/physiology , Thalamus/diagnostic imaging , Thalamus/physiology
18.
Int J Psychophysiol ; 178: 99-107, 2022 08.
Article in English | MEDLINE | ID: mdl-35750269

ABSTRACT

Though common models suggest that affect intensity can be thought of as orthogonal to arousal, examples of intensely pleasant low arousal stimuli remain rare. To support this orthogonal model, we examined whether a specific meditative sexual practice, Orgasmic Meditation (OM), induces such a state. Thus, this study measured changes in subjective affect as well as skin conductance responses (SCR), as a proxy for physiological arousal associated with sympathetic nervous system activity, during a single 15-minute partnered sexual meditative practice (Orgasmic Meditation; OM) in 93 participants. Almost all participants experienced sustained positive affect during the task. Whereas seconds after OM start approximately half the participants experienced sustained increased SCR, the other half experienced sustained decreased SCR. This observation suggests that the experience of sustained positive affect in intimate interactions may be associated with multiple mechanistic profiles including both decreased and increased arousal.


Subject(s)
Meditation , Arousal/physiology , Emotions , Humans , Sexual Behavior , Sexual Partners
19.
Sci Adv ; 8(11): eabl5547, 2022 03 18.
Article in English | MEDLINE | ID: mdl-35302854

ABSTRACT

Loss of consciousness is associated with the disruption of long-range thalamocortical and corticocortical brain communication. We tested the hypothesis that deep brain stimulation (DBS) of central thalamus might restore both arousal and awareness following consciousness loss. We applied anesthesia to suppress consciousness in nonhuman primates. During anesthesia, central thalamic stimulation induced arousal in an on-off manner and increased functional magnetic resonance imaging activity in prefrontal, parietal, and cingulate cortices. Moreover, DBS restored a broad dynamic repertoire of spontaneous resting-state activity, previously described as a signature of consciousness. None of these effects were obtained during the stimulation of a control site in the ventrolateral thalamus. Last, DBS restored a broad hierarchical response to auditory violations that was disrupted under anesthesia. Thus, DBS restored the two dimensions of consciousness, arousal and conscious access, following consciousness loss, paving the way to its therapeutical translation in patients with disorders of consciousness.


Subject(s)
Consciousness , Deep Brain Stimulation , Animals , Arousal/physiology , Consciousness/physiology , Deep Brain Stimulation/methods , Humans , Primates , Thalamus/physiology
20.
Neuroimage ; 249: 118865, 2022 04 01.
Article in English | MEDLINE | ID: mdl-35031472

ABSTRACT

Brainstem nuclei play a pivotal role in many functions, such as arousal and motor control. Nevertheless, the connectivity of arousal and motor brainstem nuclei is understudied in living humans due to the limited sensitivity and spatial resolution of conventional imaging, and to the lack of atlases of these deep tiny regions of the brain. For a holistic comprehension of sleep, arousal and associated motor processes, we investigated in 20 healthy subjects the resting-state functional connectivity of 18 arousal and motor brainstem nuclei in living humans. To do so, we used high spatial-resolution 7 Tesla resting-state fMRI, as well as a recently developed in-vivo probabilistic atlas of these nuclei in stereotactic space. Further, we verified the translatability of our brainstem connectome approach to conventional (e.g. 3 Tesla) fMRI. Arousal brainstem nuclei displayed high interconnectivity, as well as connectivity to the thalamus, hypothalamus, basal forebrain and frontal cortex, in line with animal studies and as expected for arousal regions. Motor brainstem nuclei showed expected connectivity to the cerebellum, basal ganglia and motor cortex, as well as high interconnectivity. Comparison of 3 Tesla to 7 Tesla connectivity results indicated good translatability of our brainstem connectome approach to conventional fMRI, especially for cortical and subcortical (non-brainstem) targets and to a lesser extent for brainstem targets. The functional connectome of 18 arousal and motor brainstem nuclei with the rest of the brain might provide a better understanding of arousal, sleep and accompanying motor functions in living humans in health and disease.


Subject(s)
Arousal/physiology , Brain Stem/physiology , Connectome , Magnetic Resonance Imaging , Motor Activity/physiology , Nerve Net/physiology , Adult , Brain Stem/diagnostic imaging , Connectome/methods , Female , Humans , Male , Nerve Net/diagnostic imaging
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