The temporal dynamics model of emotional memory processing: a synthesis on the neurobiological basis of stress-induced amnesia, flashbulb and traumatic memories, and the Yerkes-Dodson law

Perinatal stress modulates glutamatergic functional connectivity: A post-synaptic density immediate early gene-based network analysis

Early life stress may induce synaptic changes within brain regions associated with behavioral disorders. Here, we investigated glutamatergic functional connectivity by a postsynaptic density immediate-early gene-based network analysis. Pregnant female Sprague-Dawley rats were randomly divided into two experimental groups: one exposed to stress sessions and the other serving as a stress-free control group. Homer1 expression was evaluated by in situ hybridization technique in eighty-eight brain regions of interest of male rat offspring. Differences between the perinatal stress exposed group (PRS) (n = 5) and the control group (CTR) (n = 5) were assessed by performing the Student's t-test via SPSS 28.0.1.0 with Bonferroni correction. Additionally, all possible pairwise Spearman's correlations were computed as well as correlation matrices and networks for each experimental group were generated via RStudio and Cytoscape. Perinatal stress exposure was associated with Homer1a reduction in several cortical, thalamic, and striatal regions. Furthermore, it was found to affect functional connectivity between: the lateral septal nucleus, the central medial thalamic nucleus, the anterior part of the paraventricular thalamic nucleus, and both retrosplenial granular b cortex and hippocampal regions; the orbitofrontal cortex, amygdaloid nuclei, and hippocampal regions; and lastly, among regions involved in limbic system. Finally, the PRS networks showed a significant reduction in multiple connections for the ventrolateral part of the anteroventral thalamic nucleus after perinatal stress exposure, as well as a decrease in the centrality of ventral anterior thalamic and amygdaloid nuclei suggestive of putative reduced cortical control over these regions. Within the present preclinical setting, perinatal stress exposure is a modifier of glutamatergic early gene-based functional connectivity in neuronal circuits involved in behaviors relevant to model neurodevelopmental disorders.

The perception and passage of time during public speaking

Several studies have shown that anxious individuals experience a slower passage of time under threat conditioning. Anxiety-evoking situations have also been proposed to elevate arousal levels, which, in turn, alter one's time percept. However, the effect of social stressors on time perception remains significantly neglected. The current research aimed to investigate the impact of anxiety levels on time estimation and passage of time judgments during public speaking in healthy adults. Participants were recruited from a pool of students that had to give a presentation as part of a university course or their teaching duties. Following the presentation, they were asked to make retrospective time estimations on the duration of the latter, as well as to provide passage of time judgments. Self-reported questionnaires related to affective states, public speaking anxiety, and performance were also administered. Analysis showed that higher levels of public speaking anxiety predicted temporal overestimation and slower "feel" duration and passage of time. Moreover, the relationship between public speaking anxiety and passage of time was mediated by participants' mood states, which remained significant after -indirectly- controlling for fear of evaluation. Overall, our observations suggest that anxiety levels during public presentation significantly predict altered perception and experience of time. The latter can be explained by the speaker's mood status. Identifying the mechanisms that modulate timing under psychological stressors could complement our understanding regarding their impact on educational and social settings, as well as set the ground towards the development of early intervention and prevention strategies for those who suffer from stress-related disorders.

Integrating and fragmenting memories under stress and alcohol

Stress can powerfully influence the way we form memories, particularly the extent to which they are integrated or situated within an underlying spatiotemporal and broader knowledge architecture. These different representations in turn have significant consequences for the way we use these memories to guide later behavior. Puzzlingly, although stress has historically been argued to promote fragmentation, leading to disjoint memory representations, more recent work suggests that stress can also facilitate memory binding and integration. Understanding the circumstances under which stress fosters integration will be key to resolving this discrepancy and unpacking the mechanisms by which stress can shape later behavior. Here, we examine memory integration at multiple levels: linking together the content of an individual experience, threading associations between related but distinct events, and binding an experience into a pre-existing schema or sense of causal structure. We discuss neural and cognitive mechanisms underlying each form of integration as well as findings regarding how stress, aversive learning, and negative affect can modulate each. In this analysis, we uncover that stress can indeed promote each level of integration. We also show how memory integration may apply to understanding effects of alcohol, highlighting extant clinical and preclinical findings and opportunities for further investigation. Finally, we consider the implications of integration and fragmentation for later memory-guided behavior, and the importance of understanding which type of memory representation is potentiated in order to design appropriate interventions.

Memory circuits in dementia: The engram, hippocampal neurogenesis and Alzheimer's disease

Here, we provide an in-depth consideration of our current understanding of engrams, spanning from molecular to network levels, and hippocampal neurogenesis, in health and Alzheimer's disease (AD). This review highlights novel findings in these emerging research fields and future research directions for novel therapeutic avenues for memory failure in dementia. Engrams, memory in AD, and hippocampal neurogenesis have each been extensively studied. The integration of these topics, however, has been relatively less deliberated, and is the focus of this review. We primarily focus on the dentate gyrus (DG) of the hippocampus, which is a key area of episodic memory formation. Episodic memory is significantly impaired in AD, and is also the site of adult hippocampal neurogenesis. Advancements in technology, especially opto- and chemogenetics, have made sophisticated manipulations of engram cells possible. Furthermore, innovative methods have emerged for monitoring neurons, even specific neuronal populations, in vivo while animals engage in tasks, such as calcium imaging. In vivo calcium imaging contributes to a more comprehensive understanding of engram cells. Critically, studies of the engram in the DG using these technologies have shown the important contribution of hippocampal neurogenesis for memory in both health and AD. Together, the discussion of these topics provides a holistic perspective that motivates questions for future research.

Heart rate variability and perception of mental stress among medical students and residents at an emergency department

BACKGROUND

When Medical Residents (MR) and Medical Students (MS) are assigned to the demanding environment of an Emergency they inevitably encounter stress. The aims of this study are to measure short-term heart rate variability (HRV) before and after shifts, estimate perceived stress levels, and assess the recovery patterns after their shifts.

METHODS

We assessed HRV parameters in MS and MR using the wristband physiological monitor Polar® Verify Sense before and after day (DS) and night shifts (NS). Perceived stress levels were evaluated using the simplified State Trait Anxiety Inventory (STAI-S6) and the Subjective Units of Distress Scale.

RESULTS

This study included 60 participants of which 55% were female with a mean age of 26 years. MS presented significant reduction in sympathetic nervous system index after DS [0.68 (0.01-2.42) vs -0.22 (-0.75-1.13), p < 0.01] and NS [0.87 (-0.28-1.45) vs 0.06 (-0.70-1.04), p < 0.01], while MR maintained the same levels of sympathetic activity [DS: 1.17 (0.04 -2.88) vs 0.93 (0.50-1.41), p = 0.14; NS: 1.37 (0.76-2.21) vs 1.29 (0.35-2.18), p = 0.40]. Psychological data from STAI-S6 showed statistically significant differences when comparing before and after DS in both groups, with more perceived stress after than before DS (MS: 12 ± 4 vs 14 ± 4, p = 0.04; MR: 14 ± 4 vs 16 ± 4, p = 0.04), which was not observed at NS (MS: 12 ± 3 vs 12 ± 3, p = 0.84; MR: 15 ± 3 vs 15 ± 4, p = 0.40).

CONCLUSIONS

Short-term HRV recordings before and after day or night shifts among MR and MS revealed heightened sympathetic activity preceding each shift, with a more sustained increase observed in the MR population and more perceived stress after day shifts in both groups.

A Commentary on Fasting of Nonclinical Research Animals

This commentary discusses the implementation of fasting in nonclinical animal experimental subjects. The short-term removal of food from cages of experimental animals is in all respects innocuous. The term "stress" is ill-defined and the statutes and regulations governing animal research laboratories that exert their authority in the performance of their operations do so without substantive grounds to base compliance. The legislative and administrative history of the implementation of the Animal Welfare Act (AWA) has evolved into the development of laboratory management strategies that focus on the reduction of the biological cost of stress to the animals and the determination of when subclinical stress (eustress) becomes distress. Animal welfare is based on the tenet that in laboratories conducting animal research in compliance with Good Laboratory Practices (Title 21 USC, Chapter 13,§58), it is the study protocol and the study director that establish procedures and processes that are approved by each Institutional Animal Care and Use Committee to ensure the humane care and use of animals in research, teaching, and testing and to ensure compliance with guidelines and regulations. This approval process establishes the justification of eustress in the environment that do not rise to the threshold of distress under the AWA.

Social evaluative stress enhances central detail memory, reduces false memory, and results in intrusive memories that last for days

Few studies have quantified what an individual remembers about a laboratory-controlled stressor. Here, we aimed to replicate previous work by using a modified version of the Trier Social Stress Test (TSST) to quantify participant memory for a stressful experience. We also aimed to extend this work by quantifying false and intrusive memories that ensued. One hundred and seven participants were exposed to the TSST (stress) or the friendly TSST (f-TSST; no stress). The TSST required participants to deliver a ten-minute speech in front of two laboratory panel members as part of a mock job interview; the f-TSST required participants to casually converse with the panel members about their interests. In both conditions, the panel members interacted with (central) or did not interact with (peripheral) several objects sitting on a desk in front of them. The next day, participants' memory for the objects was assessed with recall and recognition tests. We also quantified participants' intrusive memories on Days 2, 4, 6, and 8. Stressed participants recalled more central objects and exhibited greater recognition memory, particularly for central objects, than controls. Stress also led to less false recall and more intrusive memories on Days 2 and 4. Consistent with previous work, these findings suggest that participants exhibit enhanced memory for the central details of a stressful experience; they also extend prior work by showing that participants exposed to a stressor have less false memories and experience intrusive memories for several days following the event. The modified TSST paradigm used here may be useful for researchers studying not only what participants remember about a stressful event but also their susceptibility to intrusive memory formation.

Dynamic facial emotion recognition and affective prosody recognition are associated in patients with temporal lobe epilepsy

Deficits in facial emotion recognition have frequently been established in temporal lobe epilepsy (TLE). However, static, rather than dynamic emotion recognition paradigms have been applied. Affective prosody has been insufficiently studied in TLE, and there is a lack of studies investigating associations between auditory and visual emotion recognition. We wished to investigate potential deficits in a dynamic morph task of facial emotion recognition and in an affective prosody recognition task, as well as associations between both tasks. 25 patients with TLE and 24 healthy controls (CG) performed a morph task with faces continuously changing in their emotional intensity. They had to press a button, as soon as they were able to recognize the emotion expressed, and label it accordingly. In the auditory task, subjects listened to neutral sentences spoken in varying emotional tones, and labeled the emotions. Correlation analyses were conducted across both tasks. TLE patients showed significantly reduced prosody recognition compared to CG, and in the morph task, there was a statistical trend towards significantly reduced performance for TLE. Recognition rates in both tasks were significantly associated. TLE patients show deficits in affective prosody recognition, and they may also be impaired in a morph task with dynamically changing facial expressions. Impairments in basic social-cognitive tasks in TLE seem to be modality-independent.

Fish By-Product Collagen Extraction Using Different Methods and Their Application

The processing of fishery resources results in the production of a growing quantity of byproducts, including heads, skins, viscera, intestines, frames, and fillet cutoffs. These byproducts are either wasted or utilized for the production of low-value items and fish oil. Typically, fish processing industries use only 25%, while the remaining 75% is considered as waste by-products. This review presents a comprehensive review on the extraction of collagen from fish byproducts, highlighting numerous techniques including acid-soluble collagen (ASC), enzyme-soluble collagen (ESC), ultrasound extraction, deep eutectic solvent (DES) extraction, and supercritical fluid extraction (SFE). A detailed explanation of various extraction parameters such as time, temperature, solid to liquid (S/L) ratio, and solvent/pepsin concentration is provided, which needs to be considered to optimize the collagen yield. Moreover, this review extends its focus to a detailed investigation of fish collagen applications in the biomedical sector, food sector, and in cosmetics. The comprehensive review explaining the extraction methods, extraction parameters, and the diverse applications of fish collagen provides a basis for the complete understanding of the potential of fish-derived collagen. The review concludes with a discussion of the current research and a perspective on the future development in this research field.

Effects of background noise on autonomic arousal (skin conductance level)

This study was designed to investigate the relationship between sound level and autonomic arousal using acoustic signals similar in level and acoustic properties to common sounds in the built environment. Thirty-three young adults were exposed to background sound modeled on ventilation equipment noise presented at levels ranging from 35 to 75 dBA sound pressure level (SPL) in 2 min blocks while they sat and read quietly. Autonomic arousal was measured in terms of skin conductance level. Results suggest that there is a direct relationship between sound level and arousal, even at these realistic levels. However, the effect of habituation appears to be more important overall.

The cortisol switch between vulnerability and resilience

In concert with neuropeptides and transmitters, the end products of the hypothalamus-pituitary-adrenal (HPA) axis, the glucocorticoid hormones cortisol and corticosterone (CORT), promote resilience: i.e., the ability to cope with threats, adversity, and trauma. To exert this protective action, CORT activates mineralocorticoid receptors (MR) and glucocorticoid receptors (GR) that operate in a complementary manner -as an on/off switch- to coordinate circadian events, stress-coping, and adaptation. The evolutionary older limbic MR facilitates contextual memory retrieval and supports an on-switch in the selection of stress-coping styles at a low cost. The rise in circulating CORT concentration after stress subsequently activates a GR-mediated off-switch underlying recovery of homeostasis by providing the energy for restraining the primary stress reactions and promoting cognitive control over emotional reactivity. GR activation facilitates contextual memory storage of the experience to enable future stress-coping. Such complementary MR-GR-mediated actions involve rapid non-genomic and slower gene-mediated mechanisms; they are time-dependent, conditional, and sexually dimorphic, and depend on genetic background and prior experience. If coping fails, GR activation impairs cognitive control and promotes emotional arousal which eventually may compromise resilience. Such breakdown of resilience involves a transition to a chronic stress construct, where information processing is crashed; it leads to an imbalanced MR-GR switch and hence increased vulnerability. Novel MR-GR modulators are becoming available that may reset a dysregulated stress response system to reinstate the cognitive flexibility required for resilience.

The Role of Dorsal Raphe Nucleus Serotonergic Systems in Emotional Learning and Memory in Male BALB/c Mice

Selective serotonin reuptake inhibitors (SSRIs) are the first-line pharmacological treatment for a variety of anxiety-, trauma- and stressor-related disorders. Although they are efficacious, therapeutic improvements require several weeks of treatment and are often associated with an initial exacerbation of symptoms. The dorsal raphe nucleus (DR) has been proposed as an important target for the modulation of emotional responses and the therapeutic effects of SSRIs. Using a fear-conditioning paradigm we aimed to understand how SSRIs affect emotional learning and memory, and their effects on serotonergic circuitry. Adult male BALB/c mice were treated with vehicle (n = 16) or the SSRI fluoxetine (18 mg/kg/d) acutely (n = 16), or chronically (21d, n = 16), prior to fear conditioning. Treatment was stopped, and half of the mice (n = 8/treatment group) were exposed to cued fear memory recall 72 h later. Activation of DR serotonergic neurons during fear conditioning (Experiment 1) or fear memory recall (Experiment 2), was measured using dual-label immunohistochemistry for Tph2 and c-Fos. Acute and chronic fluoxetine treatment reduced associative fear learning without affecting memory recall and had opposite effects on anxiety-like behaviour. Acute fluoxetine decreased serotonergic activity in the DR, while chronic treatment led to serotonergic activity that was indistinguishable from that of control levels in DRD and DRV subpopulations. Chronic fluoxetine facilitated fear extinction, which was associated with rostral DRD inhibition. These findings provide further evidence that SSRIs can alter aspects of learning and memory processes and are consistent with a role for discrete populations of DR serotonergic neurons in regulating fear- and anxiety-related behaviours.

Influence of rosiridin on streptozotocin-induced diabetes in rodents through endogenous antioxidants-inflammatory cytokines pathway and molecular docking study

The research was undertaken to assess the antidiabetic activity of rosiridin in the streptozotocin (STZ)-induced diabetic model. Type 2 diabetes mellitus was elicited chemically in experimental animals using STZ (60 mg/kg, i.p.). Experimental rats were arbitrarily allocated to normal control, rosiridin perse, diabetic control, and STZ + rosiridin groups. After the confirmation of diabetes, rosiridin (10 mg/kg) was given orally to the experimental animals for 30 days. Various anti-diabetic (blood glucose, insulin), hypolipidemic, anti-inflammatory (Nuclear factor kappa B, tumour necrosis factor-α, interleukin beta (IL-1β), and IL-6), antioxidant (and malondialdehyde level, hepatic function and others markers (ALT, AST, adiponectin, and FNDC5) and histopathological indices of injury were evaluated. In addition, the rosinidin was docked into the active site of NF-Kβ (1SVC), FNDC5 (4LSD) and adiponectin (5LXG) proteins with AutoDock tools. MD simulations were carried out for the complexes of rosiridin with NF-Kβ, myokine and human adiponectin receptor 1. Rosiridin treatment restored the biochemical parameters and preserved the histopathological building of the pancreas as compared to the diabetic rats. Histopathological analysis of the pancreas confirmed that rosiridin antidiabetic efficacy in the STZ-induced diabetes mellitus model. The 5LXG_rosinidin showed favourable affinity with the best binding energies at -7.534 kcal/mol. MD simulations were carried out for the complexes of rosiridin with NF-Kβ, myokine and human adiponectin receptor 1, the complex of myokine and rosiridin exhibited the most stable complex. Rosiridin may exhibit considerable anti-diabetic activity in the STZ-induced diabetes mellitus model.Communicated by Ramaswamy H. Sarma.

The effects of self-selected background music and task difficulty on task engagement and performance in a visual vigilance task

Listening to self-selected background music has been shown to be associated with increased task focus and decreased mind wandering during a sustained attention task (Kiss and Linnell, Psychological Research Psychologische Forschung 85:2313-2325, 2021). It is unclear, however, how this relation may depend on the potentially critical factor of task difficulty. To address this knowledge gap, we explored how listening to self-selected music, compared to silence, affects subjectively experienced task engagement (i.e., task focus, mind wandering, and external distraction/bodily sensation states) and task performance during either an easy or a hard vigilance task. We also examined how these effects vary with time-on-task. Our results replicated prior work demonstrating that background music enhanced task focus and decreased mind wandering, compared to silence. There was also lower reaction time variability in the background music condition relative to the silence condition. Notably, these findings held regardless of task difficulty. Interestingly, when examined over time-on-task, the presence of music led to smaller task focus declines and mind wandering increases, compared to silence. Thus, listening to self-selected music appears to confer a protective effect on task engagement, especially over time-on-task.

Strong but Fragmented Memory of a Stressful Episode

While it is commonly assumed that stressful events are vividly remembered, it remains largely unknown whether all aspects of memory for a stressful episode are enhanced. In this preregistered study, we tested whether stress enhances later remembering of individual elements of a stressful episode at the cost of impaired processing of the association between these elements. Therefore, male and female participants (N = 122) underwent a stressful (or control) episode during which they encoded a series of stimuli. To investigate stress effects on the memory for individual events and the links between these, we used temporal sequence effects in recognition memory tested 24 h after encoding. Specifically, we tested whether stress would affect the memory enhancement for a target item if this is preceded by another item that also preceded the target during encoding (recognition priming). Our results showed that participants recalled single events encoded under stress better than those encoded under nonstressful conditions, but were less able to leverage the temporal sequence of events encoded under stress to cue memory at delayed recall, reflected in reduced memory for items preceded by the item that preceded them also during encoding. Functional near-infrared spectroscopy further revealed that encoding under stress was accompanied by opposite changes in inferotemporal and dorsolateral prefrontal areas. Together, our data suggest that acute stress induces a mode of memory formation that results in strong but less integrated memories.

The Insidious Influence of Stress: An Integrated Model of Stress, Executive Control, and Psychopathology

Although exposure to acute stress undoubtedly contributes to psychopathology, most individuals do not develop psychopathology following stress exposure. To explain this, biological, emotional, and cognitive responses to stress have been implicated, but individual differences in executive control (i.e., top-down control of cognition and behavior) measured in response to stress has only recently emerged as a potential factor contributing to psychopathology. In this review, we introduce a model-the integrated model of stress, executive control, and psychopathology-positing how the impairing effects of acute stress on executive control can contribute to psychopathology. We link to research on biological, emotional, and cognitive processes, all of which can be impacted by executive control, to propose a framework for how poorer executive control under conditions of acute stress can contribute to psychopathology. This integrated model is intended to further our understanding of who is more susceptible to the negative consequences of stress.

Early- and late-phase changes of brain activity and early-phase neuromodulation in the posttraumatic stress disorder rat model

Posttraumatic stress disorder (PTSD) is a complex syndrome that may occur after life-threatening events. Fear memory abnormalities may play vital roles in the pathogenesis of PTSD. Previous work has found that fear memories are not rigid; the retrieval of fear memories may change over time. Furthermore, prior studies suggest that theta wave (4 Hz) activity is highly correlated with fear expression in an animal model. However, the relationship between pathological fear memory and potential brain wave features in PTSD remains largely uncharacterized. Here, we hypothesized that after traumatic stress exposure, the longitudinal dynamics of abnormal fears in PTSD animal models could be reflected by the measurement of local field potentials (LFPs). Using a well-established modified single-prolonged stress and footshock (SPS & FS) PTSD rat model, animals were restrained for 2 h and subsequently subjected to 20 min of forced swimming, then exposed to diethyl ether until they lost consciousness and placed in a conditioning chamber for fear conditioning. To characterize the temporal changes, we characterized freezing behavior brain wave features during the conditioning chamber re-exposure in the early (10 and 30 min; 2, 4, and 6 h) and late (day 1, 3, 7, and 14) phases after traumatic stress exposure. Our results indicate that SPS & FS rats showed co-morbid PTSD phenotypes including significantly higher levels of anxiety-, depression-, and anhedonia-like behaviors, and impaired fear extinction. Delta wave (0.5-4 Hz) suppression in the medial prefrontal cortex, amygdala, and ventral hippocampus occurred 10 and 30 min after traumatic stress, followed by continuous delta wave activity from 2 h to day 14, correlating with fear levels. tDCS reduced delta activity and alleviated PTSD-like phenotypes in the SPS & FS group. In this study, profiling abnormal fears with brain wave correlates may improve our understanding of time-dependent pathological fear memory retrieval in PTSD and facilitate the development of effective intervention strategies.

Regulation of brain cognitive states through auditory, gustatory, and olfactory stimulation with wearable monitoring

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.

Assessing attention and impulsivity in the variable stimulus duration and variable intertrial interval rodent continuous performance test schedules using noradrenaline receptor antagonists in female C57BL/6JRj mice

RATIONALE

Noradrenergic dysfunction is associated with disorders of impulsivity and inattention. The rodent continuous performance test (rCPT) quantifies changes in attention and impulsivity.

OBJECTIVE

To use NA receptor antagonists to examine the roles of NA on attention and impulsivity behaviours measured in the rCPT variable stimulus duration (vSD) and the variable intertrial interval (vITI) schedules.

METHODS

Two cohorts of 36 female C57BL/6JRj mice were examined separately in the rCPT vSD and vITI schedules. Both cohorts received antagonists of the following adrenoceptors: α1 (doxazosin, DOX: 1.0, 3.0, 10.0 mg/kg), α2 (yohimbine, YOH: 0.1, 0.3, 1.0 mg/kg), and β1/2 (propranolol, PRO: 1.0, 3.0, 10.0 mg/kg) in consecutive balanced Latin square designs with flanking reference measurements. The antagonists were subsequently examined for effects on locomotor activity.

RESULTS

DOX showed similar effects in both schedules, improving discriminability and accuracy, and reducing responding and impulsivity, and DOX also reduced locomotor activity. YOH showed prominent effects in the vSD schedule to increase responding and impulsivity, while impairing discriminability and accuracy. YOH did not affect locomotor activity. PRO increased responding and impulsivity, decreased accuracy, but did not affect discriminability or locomotor activity.

CONCLUSION

Antagonism of α2 or β1/2 adrenoceptors caused similar increases in responding and impulsivity and worsened attentional performance, while α1 adrenoceptor antagonism showed the opposite effects. Our results suggest that endogenous NA exerts bidirectional control of most behaviours in the rCPT. The parallel vSD and vITI studies showed a substantial overlap in effects, but also some differences that indicate differing sensitivity towards noradrenergic manipulations.

Effects of a True Prophylactic Treatment on Hippocampal and Amygdala Synaptic Plasticity and Gene Expression in a Rodent Chronic Stress Model of Social Defeat

Post-traumatic stress disorder (PTSD) is a complex stress-related disorder induced by exposure to traumatic stress that is characterized by symptoms of re-experiencing, avoidance, and hyper-arousal. While it is widely accepted that brain regions involved in emotional regulation and memory-e.g., the amygdala and hippocampus-are dysregulated in PTSD, the pathophysiology of the disorder is not well defined and therefore, pharmacological interventions are extremely limited. Because stress hormones norepinephrine and cortisol (corticosterone in rats) are heavily implicated in the disorder, we explored whether preemptively and systemically antagonizing β-adrenergic and glucocorticoid receptors with propranolol and mifepristone are sufficient to mitigate pathological changes in synaptic plasticity, gene expression, and anxiety induced by a modified social defeat (SD) stress protocol. Young adult, male Sprague Dawley rats were initially pre-screened for anxiety. The rats were then exposed to SD and chronic light stress to induce anxiety-like symptoms. Drug-treated rats were administered propranolol and mifepristone injections prior to and continuing throughout SD stress. Using competitive ELISAs on plasma, field electrophysiology at CA1 of the ventral hippocampus (VH) and the basolateral amygdala (BLA), quantitative RT-PCR, and behavior assays, we demonstrate that our SD stress increased anxiety-like behavior, elevated long-term potentiation (LTP) in the VH and BLA, and altered the expression of mineralocorticoid, glucocorticoid, and glutamate receptors. These measures largely reverted to control levels with the administration of propranolol and mifepristone. Our findings indicate that SD stress increases LTP in the VH and BLA and that prophylactic treatment with propranolol and mifepristone may have the potential in mitigating these and other stress-induced effects.

Neurocognitive effects of stress: a metaparadigm perspective

Stressful experiences, both physical and psychological, that are overwhelming (i.e., inescapable and unpredictable), can measurably affect subsequent neuronal properties and cognitive functioning of the hippocampus. At the cellular level, stress has been shown to alter hippocampal synaptic plasticity, spike and local field potential activity, dendritic morphology, neurogenesis, and neurodegeneration. At the behavioral level, stress has been found to impair learning and memory for declarative (or explicit) tasks that are based on cognition, such as verbal recall memory in humans and spatial memory in rodents, while facilitating those that are based on emotion, such as differential fear conditioning in humans and contextual fear conditioning in rodents. These vertically related alterations in the hippocampus, procedurally observed after subjects have undergone stress, are generally believed to be mediated by recurrently elevated circulating hypothalamic-pituitary-adrenal (HPA) axis effector hormones, glucocorticoids, directly acting on hippocampal neurons densely populated with corticosteroid receptors. The main purposes of this review are to (i) provide a synopsis of the neurocognitive effects of stress in a historical context that led to the contemporary HPA axis dogma of basic and translational stress research, (ii) critically reappraise the necessity and sufficiency of the glucocorticoid hypothesis of stress, and (iii) suggest an alternative metaparadigm approach to monitor and manipulate the progression of stress effects at the neural coding level. Real-time analyses can reveal neural activity markers of stress in the hippocampus that can be used to extrapolate neurocognitive effects across a range of stress paradigms (i.e., resolve scaling and dichotomous memory effects issues) and understand individual differences, thereby providing a novel neurophysiological scaffold for advancing future stress research.

Systemic corticosterone administration impairs the late fear memory reconsolidation via basolateral amygdala glucocorticoid receptors: dependence on the time window and memory age

Glucocorticoid receptors (GRs) of the basolateral amygdala (BLA) play an important role in memory reconsolidation. The present study investigated the role of the BLA GRs in the late reconsolidation of fear memory using an inhibitory avoidance (IA) task in male Wistar rats. Stainless steel cannulae were implanted bilaterally into the BLA of the rats. After 7 days of recovery, the animals were trained in a one-trial IA task (1mA, 3s). In Experiment one, 48h after the training session, the animals received 3 systemic doses of corticosterone (CORT; 1, 3, or 10 mg/kg, i.p.) followed by an intra-BLA microinjection of the vehicle (0.3µl/side) at different time points (immediately, 12, or 24h) after memory reactivation. Memory reactivation was performed by returning the animals to the light compartment while the sliding door was open. No shock was delivered during memory reactivation. CORT (10 mg/kg) injection 12h after memory reactivation most effectively impaired the late memory reconsolidation (LMR). In the second part of Experiment one, immediately, 12, or 24h after memory reactivation, GR antagonist RU38486 (RU; 1ng/0.3µl/side) was injected into BLA following a systemic injection of CORT (10 mg/kg) to examine whether it would block the CORT effect. RU inhibited the impairing effects of CORT on LMR. In Experiment two, the animals received CORT (10 mg/kg) with time windows immediately, 3, 6, 12, and 24h after memory reactivation. Again, CORT (10 mg/kg) injection 12h after MR impaired LMR. Memory reactivation was performed in the third Experiment, 7, 14, 28, or 56 days after the training session. Injection of CORT (10 mg/kg) 12h later had no significant effect on the LMR. The impairing effect of CORT was seen only in 2-day-old but not 7, 14, 28, and 56-day-old memories. GRs located in BLA seem to play an important role in the LMR of young memory, as with increasing the age of memories, they become less sensitive to manipulation.

Heart rate responses in critical care trainees during airway intubation: a comparison between the simulated and clinical environments

OBJECTIVE

This study aimed to compare the heart rate response to stress during airway intubations in clinical practice and a simulated environment.

METHODS

Twenty-five critical care registrars participated in the study over a 3-month period. Heart rate data during intubations was recorded by a FitBit® Charge 2 worn by each participant during their clinical practice, and during a single simulated airway management scenario. The heart rate range was calculated by subtracting the baseline working heart rate (BWHR) from the maximum functional heart rate (MFHR). For each airway intubation performed participants recorded an airway diary entry. Data from intubations performed in the clinical environment was compared to data from a simulated environment. Heart rate changes were observed in two ways: percentage rise (median) across the 20-min intubation period and; percentage rise at point of intubation (median).

RESULTS

Eighteen critical care registrars completed the study, mean age 31.8 years (SD = 2.015, 95% CI = 30.85-32.71). Throughout the 20-min peri-intubation recording period there was no significant difference in the median change in heart rates between the clinical (14.72%) and simulation (15.96%) environment (p = 0.149). At the point of intubation there was no significant difference in the median change in heart rate between the clinical (16.03%) and the simulation (25.65%) environment groups (p = 0.054).

CONCLUSION

In this small population of critical care trainees, a simulation scenario induced a comparable heart rate response to the clinical environment during intubation. This provides evidence that simulation scenarios are able to induce a comparable physiological stress response to the clinical environment and thus facilitates effective teaching of a high-risk procedure in a safe manner.

Feeding crocin ameliorate cognitive dysfunction, oxidative stress and neuroinflammation induced by unpredictable chronic mild stress in rats

INTRODUCTION

The aim of the current study was to investigate the probable mechanism and effect of crocin on brain oxidative damage and memory deficits induced by unpredictable chronic mild stress (UCMS).

MATERIALS AND METHODS

Male Wistar rats were randomly divided into six groups consisting of one vehicle group (received normal saline), four groups included rats who received UCMS 4 weeks out of which three groups were pretreated with different doses of crocin (10, 20, and 30 mg/kg/day) concomitantly. To assess the pure effect of crocin, the last experimental group received a high dose of crocin (30 mg/kg/day) without exposure to the UCMS procedure. The behavioral tests including Morris water maze (MWM) and passive avoidance (PA) were performed and eventually they were sacrificed for the estimation of biochemical parameters.

RESULTS

The increase in Malondialdehyde (MDA) as an oxidative stress indicator and nitrite levels in the hippocampus were observed in UCMS rats, along with memory deficits in behavioral tests including passive avoidance and Morris water maze (MWM) test. Moreover, treatment with crocin decreased MDA, nitrite, pro-inflammatory cytokine such as TNF-α, and pathological hallmark of Alzheimer's disease including amyloid-β (Aβ), and glial fibrillary acidic protein (GFAP) in the hippocampus, whereas antioxidant agents including total thiol content, SOD, and catalase activity were increased. Also behavioral test demonstrated a positive effect of crocin on memory deficit induced by UCMS. Interlukin-10 as an important anti-inflammatory agent was increased as well. Interestingly, in some behavioral and biochemical findings, treatment with 30 mg/kg of crocin has given better results compared to vehicle group, which means the administration of crocin could have preventive effects on learning and memory impairment.

CONCLUSION

The present study strongly confirmed the positive effect of crocin and has the potential as an antioxidant and anti-inflammatory agent that could improve memory impairment induced by UCMS.

Pre-Learning Stress That Is Temporally Removed from Acquisition Impairs Fear Learning

Few studies have examined the time-dependent effects of stress on fear learning. Previously, we found that stress immediately before fear conditioning enhanced fear learning. Here, we aimed to extend these findings by assessing the effects of stress 30 min prior to fear conditioning on fear learning and fear generalization. Two hundred and twenty-one healthy adults underwent stress (socially evaluated cold pressor test) or a control manipulation 30 min before completing differential fear conditioning in a fear-potentiated startle paradigm. One visual stimulus (CS+), but not another (CS-), was associated with an aversive airblast to the throat (US) during acquisition. The next day, participants were tested for their fear responses to the CS+, CS-, and several generalization stimuli. Stress impaired the acquisition of fear on Day 1 but had no significant impact on fear generalization. The stress-induced impairment of fear learning was particularly evident in participants who exhibited a robust cortisol response to the stressor. These findings are consistent with the notion that stress administered 30 min before learning impairs memory formation via corticosteroid-related mechanisms and may help us understand how fear memories are altered in stress-related psychological disorders.

Tonic Immobility as a Defensive Trauma Response to Rape: Bridging Public Health and Law

There is widespread scientific evidence that validates tonic immobility (TI) as part of the trauma response in victims of rape, and criminal justice practitioners are increasingly trained in trauma-informed approaches. Yet, legal and policy definitions of consent do not fully recognize TI during the incident as evidence of nonconsent. Using a systematic review of U.S. law and policy regarding sexual violence and consent, this paper analyzes the substantial legal reform of rape law and definitions of consent, suggesting ways to further integrate TI into existing law and legal practices to improve public health approaches and justice responses for victims.

Perceptual Difficulty Regulates Attentional Gain Modulations in Human Visual Cortex

Perceptual difficulty is sometimes used to manipulate selective attention. However, these two factors are logically distinct. Selective attention is defined by priority given to specific stimuli based on their behavioral relevance, whereas perceptual difficulty is often determined by perceptual demands required to discriminate relevant stimuli. That said, both perceptual difficulty and selective attention are thought to modulate the gain of neural responses in early sensory areas. Previous studies found that selectively attending to a stimulus or increasing perceptual difficulty enhanced the gain of neurons in visual cortex. However, some other studies suggest that perceptual difficulty can have either a null or even reversed effect on gain modulations in visual cortex. According to Yerkes-Dodson's Law, it is possible that this discrepancy arises because of an interaction between perceptual difficulty and attentional gain modulations yielding a nonlinear inverted-U function. Here, we used EEG to measure modulations in the visual cortex of male and female human participants performing an attention-cueing task where we systematically manipulated perceptual difficulty across blocks of trials. The behavioral and neural data implicate a nonlinear inverted-U relationship between selective attention and perceptual difficulty: a focused-attention cue led to larger response gain in both neural and behavioral data at intermediate difficulty levels compared with when the task was more or less difficult. Moreover, difficulty-related changes in attentional gain positively correlated with those predicted by quantitative modeling of the behavioral data. These findings suggest that perceptual difficulty mediates attention-related changes in perceptual performance via selective neural modulations in human visual cortex.SIGNIFICANCE STATEMENT Both perceptual difficulty and selective attention are thought to influence perceptual performance by modulating response gain in early sensory areas. That said, less is known about how selective attention interacts with perceptual difficulty. Here, we measured neural gain modulations in the visual cortex of human participants performing an attention-cueing task where perceptual difficulty was systematically manipulated. Consistent with Yerkes-Dodson's Law, our behavioral and neural data implicate a nonlinear inverted-U relationship between selective attention and perceptual difficulty. These results suggest that perceptual difficulty mediates attention-related changes in perceptual performance via selective neural modulations in visual cortex, extending our understanding of the attentional operation under different levels of perceptual demands.

Toward Antifragility: Social Defeat Stress Enhances Learning and Memory in Young Mice Via Hippocampal Synaptosome Associated Protein 25

Social adversity not only causes severe psychological diseases but also may improve people's ability to learn and grow. However, the beneficial effects of social adversity are often ignored. In this study, we investigated whether and how social adversity affects learning and memory in a mouse social defeat stress (SDS) model. A total of 652 mice were placed in experimental groups of six to 23 mice each. SDS enhanced spatial, novelty, and fear memory with increased synaptosome associated protein 25 (SNAP-25) level and dendritic spine density in hippocampal neurons among young but not middle-aged mice. Chemogenetic inhibition of hippocampal CaMK2A+ neurons blocked SDS-induced enhancement of learning or memory. Knockdown of SNAP-25 or blockade of N-methyl-D-aspartate (NMDA) receptor subunit GluN2B in the hippocampus prevented SDS-induced learning memory enhancement in an emotion-independent manner. These findings suggest that social adversity promotes learning and memory ability in youths and provide a neurobiological foundation for biopsychological antifragility.

Effects of reading contextualized physics problems among men and women: A psychophysiological approach

To counteract declining interest in science, contextualizing course material has been suggested, despite little evidence supporting this strategy. We assessed how reading physics problems in different contexts-none, technical, or humanistic-impacted performance and implicit cognitive and affective situational interest (SI) among undergraduate men and women (n = 60). We hypothesized that contextualized problems would increase cognitive SI, boosting performance. We also investigated existing hypotheses that this influence would be stronger when contexts matched stereotypical gender interests. Pupillometric and electroencephalographic data served to indicate cognitive SI, while electrodermal activity (EDA) and valence were measures of affective SI. Significantly higher valence was observed in decontextualized than humanistic problems (p = 0.003) specifically among men (p < 0.001). Greater EDA (p = 0.019) and decontextualized problems (p < 0.001) yielded greater performance than contextualized problems for all participants. Results emphasize the importance of affective SI and of avoiding gender biases in curricular development. This study encourages caution if implementing contextualization.

Glucocorticoid-Responsive Tissue Plasminogen Activator (tPA) and Its Inhibitor Plasminogen Activator Inhibitor-1 (PAI-1): Relevance in Stress-Related Psychiatric Disorders

Stressful events trigger a set of complex biological responses which follow a bell-shaped pattern. Low-stress conditions have been shown to elicit beneficial effects, notably on synaptic plasticity together with an increase in cognitive processes. In contrast, overly intense stress can have deleterious behavioral effects leading to several stress-related pathologies such as anxiety, depression, substance use, obsessive-compulsive and stressor- and trauma-related disorders (e.g., post-traumatic stress disorder or PTSD in the case of traumatic events). Over a number of years, we have demonstrated that in response to stress, glucocorticoid hormones (GCs) in the hippocampus mediate a molecular shift in the balance between the expression of the tissue plasminogen activator (tPA) and its own inhibitor plasminogen activator inhibitor-1 (PAI-1) proteins. Interestingly, a shift in favor of PAI-1 was responsible for PTSD-like memory induction. In this review, after describing the biological system involving GCs, we highlight the key role of tPA/PAI-1 imbalance observed in preclinical and clinical studies associated with the emergence of stress-related pathological conditions. Thus, tPA/PAI-1 protein levels could be predictive biomarkers of the subsequent onset of stress-related disorders, and pharmacological modulation of their activity could be a potential new therapeutic approach for these debilitating conditions.

Formal perspectives on shared interbrain activity in social communication: Insights from information and control theories

The mechanisms underlying a reorientation of neuroscience from a single-brain to a multi-brain frame of reference have long been with us. These revolve around the evolutionary exaptation of the inevitable second-law 'leakage' of crosstalk between co-resident cognitive phenomena. Crosstalk characterizes such processes as immune response, wound-healing, gene expression, as so on, up through and including far more rapid neural processes. It is not a great leap-of-faith to infer that similar phenomena affect/afflict social interactions between individuals within and across populations.

Slower tempo makes worse performance? The effect of musical tempo on cognitive processing speed

The effects of musical tempo on cognitive processing speed were investigated, and the mediating effect of arousal was empirically tested. In an experiment, participants were divided into fast tempo, slow tempo, and no-music groups and completed three cognitive processing speed tests measuring motor speed, visuospatial processing speed, and linguistic processing speed. The results indicated a significant effect of musical tempo on processing speed and task performance in all three tasks. The slow-tempo group exhibited slower processing speed and worse performance than the no-music group in all three tasks. The fast tempo group displayed no significant difference in processing speed or performance compared with the no-music group. In the linguistic processing task, those who listened to slow-tempo music had better accuracy than those in the other conditions. Arousal did not mediate the relationship between musical tempo and cognitive processing speed.

Stress disrupts insight-driven mnemonic reconfiguration in the medial temporal lobe

Memories are not stored in isolation. Insight into the relationship of initially unrelated events may trigger a flexible reconfiguration of the mnemonic representation of these events. Such representational changes allow the integration of events into coherent episodes and help to build up-to-date-models of the world around us. This process is, however, frequently impaired in stress-related mental disorders resulting in symptoms such as fragmented memories in PTSD. Here, we combined a real life-like narrative-insight task, in which participants learned how initially separate events are linked, with fMRI-based representational similarity analysis to test if and how acute stress interferes with the insight-driven reconfiguration of memories. Our results showed that stress reduced the activity of medial temporal and prefrontal areas when participants gained insight into the link between events. Moreover, stress abolished the insight-related increase in representational dissimilarity for linked events in the anterior part of the hippocampus as well as its association with measures of subsequent memory that we observed in non-stressed controls. However, memory performance, as assessed in a forced-choice recognition test, was even enhanced in the stress group. Our findings suggest that acute stress impedes the neural integration of events into coherent episodes but promotes long-term memory for these integrated narratives and may thus have implications for understanding memory distortions in stress-related mental disorders.

Are cognitive aspects of defense a core feature of anxiety and depression?

Anxiety and depression are highly prevalent behavior disorders, particularly in women. Recent preclinical work using animal models has been suboptimal in predicting the efficacy of drugs targeted at these conditions, suggesting a potential discrepancy between such models and the human disorders. Notably female animals tend to be equal to, or less responsive than, males in these tasks. A number of analyses suggest that mammalian defense patterns are complex: In addition to relatively discrete and immediate fight, flight, and freezing responses, a risk assessment pattern may occur in response to threat stimuli or situations with ambiguous elements. This pattern combines defensiveness with a number of cognition-linked behaviors such as sensory attention and orientation, approach, contact, and investigation of the potential threat. Studies measuring elements of this pattern suggest that female rats, and perhaps female mice, show higher levels than equivalent males. Higher female involvement may also occur in tasks involving learning/generalization/extinction of defensiveness to conditioned stimuli. Such findings are consonant with recent analyses of "female survival strategies" based on differential adaptiveness of cognitive components of defensiveness in females, due to the necessity of female care of offspring until they are independent. These data suggest the value of additional behavioral and functional analyses of cognitive aspects of defensive behavior; contributing to both an understanding of their underlying mechanisms, and providing more sensitive measures of drug responsivity for use with animal models.

Sense of agency may not improve recollection and familiarity in recognition memory

Sense of agency (SoA) is a feeling of controlling one's own action. Recognition memory can improve for stimuli that involve SoA perhaps because of the self-reference effect. Recognition memory consists of recollection (i.e., detailed memory of stimuli) and familiarity (i.e., a feeling that stimuli are in memory). The self-reference effect is often observed in the recollection. Here, we investigated whether SoA particularly improves the recollection process. Participants pressed a key to produce an outcome (i.e., box movement followed by word presentation in Experiment 1 or word presentation in Experiment 2) and rated their SoA over the outcome. The outcome was spatially congruent or incongruent with the action. The participants learned the words intentionally (Experiment 1) or incidentally (Experiment 2). Performances of recollection and familiarity were assessed using the remember/know procedure. Our results suggest that the participants' SoA was successfully manipulated. However, contrary to our hypothesis and previous findings, we found no effects of voluntary action and action-outcome congruence on recollection and familiarity processes of recognition memory, regardless of the latency of word presentation and learning strategies. Further studies are needed to replicate and elucidate the relationship between the SoA and recognition memory.

Associations between anxiety, centromedial amygdala volume, and complex verbal fluency in middle-aged to older adults

Symptoms of anxiety are related to decreases in cognitive performance in middle-aged to older adults (i.e., ages 50 and older; MOA). Verbal fluency (VF), assessed with the Delis-Kaplan Executive Function System (D-KEFS) Category Switching (VF-CS) task, captures elements of executive function such as semantic memory, response initiation and inhibition, and cognitive flexibility. The present study examined the link between anxiety symptoms and VF-CS to better understand how this association affects such executive functions in MOA. We hypothesized that higher subclinical Beck Anxiety Inventory (BAI) scores would be associated with lower VF-CS. To further investigate the underlying neurobiological basis of an expected inverse relationship, total amygdala volume, centromedial amygdala (CMA) volume, and basolateral amygdala (BLA) volume were examined as they related to VF-CS scores on the D-KEFS. Based on extant research on connectivity and functioning between the CMA and BLA, we hypothesized that larger BLA volumes would be associated with lower anxiety scores and exhibit positive relationships with VF-CS. A sample of 63 MOA were recruited from the Providence, Rhode Island area as a part of a parent study on cardiovascular diseases. Participants completed self-report measures about physical and emotional health, a neuropsychological assessment, and a magnetic resonance imaging scan (MRI). Multiple hierarchical regressions were performed to examine relationships between variables of interest. Contrary to hypotheses, no significant relationship emerged between VF-CS and BAI scores, and BLA volume was not associated with either BAI scores or VF-CS. However, a significant positive relationship was observed between CMA volume and VF-CS. The significant relationship found between CMA and VF-CS may reflect the upward slope of the quadratic relationship between arousal and cognitive performance on the Yerkes-Dodson curve. These findings newly implicate CMA volume specifically as a possible neuromarker linking emotional arousal and cognitive performance in MOA.

Therapeutic effects of exercise-accompanied escitalopram on synaptic potency and long-term plasticity in the hippocampal CA1 area in rats under chronic restraint stress

Objectives

Administration of antidepressants and exercise are among the therapeutic approaches to chronic stress. Therefore, this study compared the therapeutic effects of different doses of escitalopram, exercise, and exercise-accompanied escitalopram on synaptic potency and long-term plasticity in the hippocampal CA1 area in rats under chronic restraint stress.

Materials and Methods

The rats were allocated to different groups. The chronic restraint stress (6 hr/day) continued for 14 days. Injection of escitalopram (10 and 20 mg/kg) and treadmill running (1 hr/day) were performed after the stress induction. The input/output (I/O) functions and LTP induction were evaluated in the hippocampal CA1 area.

Results

The fEPSP slope and amplitude after the LTP induction significantly decreased in the chronically stressed group. However, the serum corticosterone levels had significant enhancement in this group. In addition to serum corticosterone levels, the fEPSP slope and amplitude after the LTP induction were enhanced by exercise, escitalopram 20 mg/kg alone, and exercise-accompanied escitalopram 10 and/or 20 mg/kg in chronically stressed groups.

Conclusion

Overall, chronic stress impaired synaptic potency and long-term plasticity. These impairments were effectively reversed by exercise, escitalopram 20 mg/kg alone, and exercise-accompanied escitalopram 10 and 20 mg/kg. However, escitalopram 10 mg/kg alone could not alleviate the memory deficits in chronically stressed subjects. Therefore, exercise with both doses of escitalopram seems to have had additive effects on chronic stress conditions.

The effect of background music on stress in the operating surgeon: scoping review

Background

Despite the ubiquitous sounds of music playing in operating theatres (OTs) around the world, the effect that music has on intraoperative clinician stress is ill-defined. In the present scoping review the aim was to map the available evidence for the effect of background music in the OT on the experience of stress in the operating surgeon.

Methods

The present review was conducted in accordance with the PRISMA Protocols for Scoping Reviews. Using Embase, MEDLINE, and the Cochrane databases, peer-reviewed research studies reporting the effect of intraoperative background music on an outcome measure of clinician stress or respondent perceptions on this effect were included.

Results

A total of 4342 studies were screened and 15 studies met the inclusion criteria, of which 10 were interventional studies, and five were observational survey-based studies. Of the 10 interventional studies, four showed reduced anxiety and mental workload scores with music, although only two demonstrated a significant improvement in a physiological outcome. The survey-based studies generally reported a positive perception among surgeons and theatre staff towards the effect of music on OT stress.

Conclusion

While there is generally a positive perception towards intraoperative music and surgeon stress, there are few objective physiological and psychological data to support this. Studies were varied in their design. The present review can be used to guide future experimental, observational, and mixed-method research on this topic.

Decreased sympathetic cardiovascular influences and hormone-physiological changes in response to Covid-19-related adaptations under different learning environments

To examine the implications of the transition from face-to-face to online learning from a psychobiological perspective, this study investigated potential differences in physiological stress parameters of students engaged in online or face-to-face learning and determined whether these can be identified as possible mediators between learning experience and achievement emotions. In a randomized experimental field study, medical students (n = 82) attended either regular face-to-face classes of the microscopic anatomy course or the same practical course online using Zoom videoconferencing platform. The present study investigated Heart Rate Variability (HRV) and salivary cortisol concentration as stress correlates, within the contexts of online and face-to-face learning and compared these parameters with a control group that was measured at rest. Additionally, participants completed a standardized questionnaire about their experienced emotions in relation to task achievement and subjective stress levels. A significant reduction in HRV was found in face-to-face learning, suggesting stronger stress responses in the face-to-face learning environment (η²  = 0.421, P < 0.001). Furthermore, participants engaged in face-to-face learning showed significantly higher cortisol concentrations (η²  = 0.115, P = 0.032). Additionally, increased sympathetic activation correlated with the discrete positive emotion of enjoyment exclusively within the face-to-face condition (r = 0.365, P = 0.043). These results indicate that the transfer of a face-to-face practical course in microscopic anatomy to an online learning environment is associated with decreased sympathetic and enhanced vagal cardiovascular influences, together with lower cortisol concentrations in healthy medical students.

Assessment of the Patient’s Emotional Response with the RobHand Rehabilitation Platform: A Case Series Study

Cerebrovascular accidents have physical, cognitive and emotional effects. During rehabilitation, the main focus is placed on motor recovery, yet the patient’s emotional state should also be considered. For this reason, validating robotic rehabilitation systems should not only focus on their effectiveness related to the physical recovery but also on the patient’s emotional response. A case series study has been conducted with five stroke patients to assess their emotional response towards therapies using RobHand, a robotic hand rehabilitation platform. Emotional state was evaluated in three dimensions (arousal, valence and dominance) using a computer-based Self-Assessment Manikin (SAM) test. It was verified that the emotions induced by the RobHand platform were successfully distributed in the three-dimensional emotional space. The increase in dominance and the decrease in arousal during sessions reflects that patients had become familiar with the rehabilitation platform, resulting in an increased feeling of control and finding the platform less attractive. The results also reflect that patients found a therapy based on a virtual environment with a realistic scenario more pleasant and attractive.

Oxytocin: An Old Hormone, A Novel Psychotropic Drug And Possible Use In Treating Psychiatric Disorders

BACKGROUND

Oxytocin is a nonapeptide synthesized in the paraventricular and supraoptic nuclei of the hypothalamus. Historically, this molecule has been involved as a key factor in the formation of infant attachment, maternal behavior and pair bonding and, more generally, in linking social signals with cognition, behaviors and reward. In the last decades, the whole oxytocin system has gained a growing interest as it was proposed to be implicated in etiopathogenesis of several neurodevelopmental and neuropsychiatric disorders.

METHODS

With the main goal of an in-depth understanding of the oxytocin role in the regulation of different functions and complex behaviors as well as its intriguing implications in different neuropsychiatric disorders, we performed a critical review of the current state of art. We carried out this work through PubMed database up to June 2021 with the search terms: 1) "oxytocin and neuropsychiatric disorders"; 2) "oxytocin and neurodevelopmental disorders"; 3) "oxytocin and anorexia"; 4) "oxytocin and eating disorders"; 5) "oxytocin and obsessive-compulsive disorder"; 6) "oxytocin and schizophrenia"; 7) "oxytocin and depression"; 8) "oxytocin and bipolar disorder"; 9) "oxytocin and psychosis"; 10) "oxytocin and anxiety"; 11) "oxytocin and personality disorder"; 12) "oxytocin and PTSD".

RESULTS

Biological, genetic, and epigenetic studies highlighted quality and quantity modifications in the expression of oxytocin peptide or in oxytocin receptor isoforms. These alterations would seem to be correlated with a higher risk of presenting several neuropsychiatric disorders belonging to different psychopathological spectra. Collaterally, the exogenous oxytocin administration has shown to ameliorate many neuropsychiatric clinical conditions.

CONCLUSION

Finally, we briefly analyzed the potential pharmacological use of oxytocin in patient with severe symptomatic SARS-CoV-2 infection due to its anti-inflammatory, anti-oxidative and immunoregulatory properties.

Pneumonia Classification from X-ray Images with Inception-V3 and Convolutional Neural Network

Pneumonia is one of the leading causes of death in both infants and elderly people, with approximately 4 million deaths each year. It may be a virus, bacterial, or fungal, depending on the contagious pathogen that damages the lung’s tiny air sacs (alveoli). Patients with underlying disorders such as asthma, a weakened immune system, hospitalized babies, and older persons on ventilators are all at risk, particularly if pneumonia is not detected early. Despite the existing approaches for its diagnosis, low accuracy and efficiency require further research for more accurate systems. This study is a similar endeavor for the detection of pneumonia by the use of X-ray images. The dataset is preprocessed to make it suitable for transfer learning tasks. Different pre-trained convolutional neural network (CNN) variants are utilized, including VGG16, Inception-v3, and ResNet50. Ensembles are made by incorporating CNN with Inception-V3, VGG-16, and ResNet50. Besides the common evaluation metrics, the performance of the pre-trained and ensemble deep learning models is measured with Cohen’s kappa as well as the area under the curve (AUC). Experimental results show that Inception-V3 with CNN attained the highest accuracy and recall score of 99.29% and 99.73%, respectively.

Long-Term Potentiation-Like Visual Synaptic Plasticity Is Negatively Associated With Self-Reported Symptoms of Depression and Stress in Healthy Adults

Long-term potentiation (LTP) is one of the most extensively studied forms of neuroplasticity and is considered the strongest candidate mechanism for memory and learning. The use of event-related potentials and sensory stimulation paradigms has allowed for the translation from animal studies to non-invasive studies of LTP-like synaptic plasticity in humans. Accumulating evidence suggests that synaptic plasticity as measured by stimulus-specific response modulation is reduced in neuropsychiatric disorders such as major depressive disorder (MDD), bipolar disorders and schizophrenia, suggesting that impaired synaptic plasticity plays a part in the underlying pathophysiology of these disorders. This is in line with the neuroplasticity hypothesis of depression, which postulate that deficits in neuroplasticity might be a common pathway underlying depressive disorders. The current study aims to replicate and confirm earlier reports that visual stimulus-specific response modulation is a viable probe into LTP-like synaptic plasticity in a large sample of healthy adults (n = 111). Further, this study explores whether impairments in LTP-like synaptic plasticity is associated with self-reported subclinical depressive symptoms and stress in a healthy population. Consistent with prior research, the current study replicated and confirmed reports demonstrating significant modulation of visual evoked potentials (VEP) following visual high-frequency stimulation. Current results further indicate that reduced LTP-like synaptic plasticity is associated with higher levels of self-reported symptoms of depression and perceived stress. This indicate that LTP-like plasticity is sensitive to sub-clinical levels of psychological distress, and might represent a vulnerability marker for the development of depressive symptoms.

Biogenic Preparation, Characterization, and Biomedical Applications of Chitosan Functionalized Iron Oxide Nanocomposite

Chitosan (CS) functionalization over nanomaterials has gained more attention in the biomedical field due to their biocompatibility, biodegradability, and enhanced properties. In the present study, CS functionalized iron (II) oxide nanocomposite (CS/FeO NC) was prepared using Sida acuta leaf extract by a facile and eco-friendly green chemistry route. Phyto-compounds of S. acuta leaf were used as a reductant to prepare CS/FeO NC. The existence of CS and FeO crystalline peaks in CS/FeO NC was confirmed by XRD. FE-SEM analysis revealed that the prepared CS/FeO NC were spherical with a 10–100 nm average size. FTIR analyzed the existence of CS and metal-oxygen bands in the prepared NC. The CS/FeO NC showed the potential bactericidal activity against E. coli, B. subtilis, and S. aureus pathogens. Further, CS/FeO NC also exhibited the dose-dependent anti-proliferative property against human lung cancer cells (A549). Thus, the obtained outcomes revealed that the prepared CS/FeO NC could be a promising candidate in the biomedical sector to inhibit the growth of bacterial pathogens and lung cancer cells.

Arousal state affects perceptual decision-making by modulating hierarchical sensory processing in a large-scale visual system model

Arousal levels strongly affect task performance. Yet, what arousal level is optimal for a task depends on its difficulty. Easy task performance peaks at higher arousal levels, whereas performance on difficult tasks displays an inverted U-shape relationship with arousal, peaking at medium arousal levels, an observation first made by Yerkes and Dodson in 1908. It is commonly proposed that the noradrenergic locus coeruleus system regulates these effects on performance through a widespread release of noradrenaline resulting in changes of cortical gain. This account, however, does not explain why performance decays with high arousal levels only in difficult, but not in simple tasks. Here, we present a mechanistic model that revisits the Yerkes-Dodson effect from a sensory perspective: a deep convolutional neural network augmented with a global gain mechanism reproduced the same interaction between arousal state and task difficulty in its performance. Investigating this model revealed that global gain states differentially modulated sensory information encoding across the processing hierarchy, which explained their differential effects on performance on simple versus difficult tasks. These findings offer a novel hierarchical sensory processing account of how, and why, arousal state affects task performance.