A two-dimensional neuropsychology of defense: fear/anxiety and defensive distance

Mortality Awareness: New Directions

Thinking about our own death and its salience in relation to decision making has become a fruitful area of multidisciplinary research across the breadth of psychological science. By bringing together experts from philosophy, cognitive and affective neuroscience, clinical and computational psychiatry we have attempted to set out the current state of the art and point to areas of further enquiry. One stimulus for doing this is the need to engage with policy makers who are now having to consider guidelines on suicide and assisted suicide so that they may be aware of their own as well as the wider populations' cognitive processes when confronted with the ultimate truth of mortality.

Orbitofrontal and Prelimbic Cortices Serve Complementary Roles in Adapting Reward Seeking to Learned Anxiety

BACKGROUND

Anxiety is a common symptom of several mental health disorders and adversely affects motivated behaviors. Anxiety can emerge from associating risk of future harm while engaged in goal-guided actions. Using a recently developed behavioral paradigm to model this aspect of anxiety, we investigated the role of 2 cortical subregions, the prelimbic medial frontal cortex (PL) and lateral orbitofrontal cortex (lOFC), which have been implicated in anxiety and outcome expectation, in flexible representation of actions associated with harm risk.

METHODS

A seek-take reward-guided instrumental task design was used to train animals (N = 8) to associate the seek action with a variable risk of punishment. After learning, animals underwent extinction training for this association. Fiber photometry was used to measure and compare neuronal activity in the PL and lOFC during learning and extinction.

RESULTS

Animals increased action suppression in response to punishment contingencies. This increase dissipated after extinction training. These behavioral changes were associated with region-specific changes in neuronal activity. PL neuronal activity preferentially adapted to the threat of punishment, whereas lOFC activity adapted to safe aspects of the task. Moreover, correlated activity between these regions was suppressed during actions associated with harm risk, suggesting that these regions may guide behavior independently under anxiety.

CONCLUSIONS

These findings suggest that the PL and lOFC serve distinct but complementary roles in the representation of learned anxiety. This dissociation may provide a mechanism to explain how overlapping cortical systems are implicated in reward-guided action execution during anxiety.

Resting-state functional connectivity in anxiety disorders: a multicenter fMRI study

Anxiety disorders (AD) are associated with altered connectivity in large-scale intrinsic brain networks. It remains uncertain how much these signatures overlap across different phenotypes due to a lack of well-powered cross-disorder comparisons. We used resting-state functional magnetic resonance imaging (rsfMRI) to investigate differences in functional connectivity (FC) in a cross-disorder sample of AD patients and healthy controls (HC). Before treatment, 439 patients from two German multicenter clinical trials at eight different sites fulfilling a primary diagnosis of panic disorder and/or agoraphobia (PD/AG, N = 154), social anxiety disorder (SAD, N = 95), or specific phobia (SP, N = 190) and 105 HC underwent an 8 min rsfMRI assessment. We performed categorical and dimensional regions of interest (ROI)-to-ROI analyses focusing on connectivity between regions of the defensive system and prefrontal regulation areas. AD patients showed increased connectivity between the insula and the thalamus compared to controls. This was mainly driven by PD/AG patients who showed increased (insula/hippocampus/amygdala-thalamus) and decreased (dorsomedial prefrontal cortex/periaqueductal gray-anterior cingulate cortex) positive connectivity between subcortical and cortical areas. In contrast, SAD patients showed decreased negative connectivity exclusively in cortical areas (insula-orbitofrontal cortex), whereas no differences were found in SP patients. State anxiety associated with the scanner environment did not explain the FC between these regions. Only PD/AG patients showed pronounced connectivity changes along a widespread subcortical-cortical network, including the midbrain. Dimensional analyses yielded no significant results. The results highlighting categorical differences between ADs at a systems neuroscience level are discussed within the context of personalized neuroscience-informed treatments. PROTECT-AD's registration at NIMH Protocol Registration System: 01EE1402A and German Register of Clinical Studies: DRKS00008743. SpiderVR's registration at ClinicalTrials.gov: NCT03208400.

The Association Between Prenatal Maternal Stress and Adolescent Affective Outcomes is Mediated by Childhood Maltreatment and Adolescent Behavioral Inhibition System Sensitivity

Prenatal maternal stress is linked to offspring outcomes; however, there is little research on adolescents, behavioral, transdiagnostic outcomes, or the mechanisms through which relations operate. We examined, in N = 268 adolescents (Mage = 15.31 years; SD = 1.063; 57.8% boys) whether prenatal maternal stress is associated with adolescent affective outcomes; whether this association is mediated, serially, by childhood home atmosphere and adolescent behavioral inhibition system (BIS) sensitivity; and whether mediational effects are moderated by adolescent attention-deficit/hyperactivity disorder or maternal internalizing symptomology. Prenatal maternal daily stress and major life events were associated with adolescent outcomes through childhood negative atmosphere/neglect and BIS sensitivity, with no evidence of moderation. Results have implications regarding the effect of prenatal maternal stress on offspring outcomes and regarding corresponding sensitive periods.

Signaling High Sensitivity to Influence Others: Initial Evidence for the Roles of Reinforcement Sensitivity, Sensory Processing Sensitivity, and the Dark Triad

Signaling high sensitivity to others may help individuals with heightened sensitivity to stimuli to craft their social relations to a preferred activation level ("assertive signaling of specific needs" hypothesis). Signaling sensitivity could be also a deceptive strategy helping to extract resources or obtain the desired treatment ("deceptive signaling" hypothesis). The study presents the construction of the measure of signaling high sensitivity to influence others and an initial test of both hypotheses. Two hundred and one participants ranging in age from 18 to 67 (M = 25.6; SD = 7.03) reported on their reinforcement sensitivity (behavioral approach and inhibition system), sensory processing sensitivity, and the Dark Triad. Signaling high sensitivity to influence others was weakly, but significantly, associated with behavioral inhibition system sensitivity, which was consistent with the "assertive signaling of specific needs" hypothesis. The behavioral approach system was positively correlated with signaling high sensitivity, which indicated that this influence strategy could be treated as an assertive self-presentational strategy helping in achieving social rewards for individuals with high reward responsiveness. Narcissism and psychopathy accounted for an additional amount of variance in signaling high sensitivity over and beyond reinforcement sensitivity. This was consistent with the "deceptive signaling" hypothesis. Signaling high sensitivity could be regarded as a strategy to achieve social goals using deception rather than as an expression of sensitive personality.

Self-other boundary under social threat in schizophrenia

Spatial representation of the self plays a vital role constructing our sense of bodily self-boundary that distinguishes the self from others. This perceptual border, known as the peripersonal space (PPS), has been suggested to be altered in individuals with schizophrenia (SZ). PPS represents a protective defensive zone that triggers alarm signals upon threat detection; thus disrupted PPS could lead to social interactional difficulties. However, very little is known about the impact of threat on PPS. To address this gap, a visual-tactile response-time (RT) experiment was conducted in immersive virtual reality (VR) for SZ and matched controls (CO). Participants were asked to detect a tactile vibration on their hand while an avatar (either threatening or neutral) approached them. Avatars were presented at different distance from the participants. PPS size and slope were estimated by identifying significant RT drop at the hypothesized self-other boundary. We also examined the relationship between PPS parameters, clinical symptoms and social disconnection. There was no overall group difference in PPS size. Perceived social threat posed in the avatars sharpened the self-boundary in CO but not in SZ. In SZ, shallower PPS slope was associated with delusion, persecution, negative symptoms and loneliness but not in CO. These results show that the regulation of self-other boundary in response to impending social threat may be maladaptive in SZ. Further research is needed on the causal mechanisms between self-disturbance and social impairments.

Psychedelics: A review of their effects on recalled aversive memories and fear/anxiety expression in rodents

Threatening events and stressful experiences can lead to maladaptive memories and related behaviors. Existing treatments often fail to address these issues linked to anxiety/stress-related disorders effectively. This review identifies dose ranges associated with specific actions across various psychedelics. We examined psilocybin/psilocin, lysergic acid diethylamide (LSD), N,N-dimethyltryptamine (DMT), mescaline, 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), serotonin 2 A/2 C agonists (e.g., DOI) and 3,4-methylenedioxymethamphetamine (MDMA) on aversive memory extinction and reconsolidation, learned fear, anxiety, and locomotion in rodents. Nearly 400 studies published since 1957 were reviewed. Psychedelics often show biphasic effects on locomotion at doses that enhance extinction learning/retention, impair memory reconsolidation, or reduce learned fear and anxiety. Emerging evidence suggests a dissociation between their prospective benefits and locomotor effects. Under-explored aspects include sex differences, susceptibility to interference as memories age and generalize, repeated treatments, and immediate vs. delayed changes. Validating findings in traumatic-like memory and maladaptive fear/anxiety models is essential. Understanding how psychedelics modulate threat responses and post-retrieval memory processes in rodents may inform drug development and human studies, improving therapeutic approaches for related psychiatric conditions.

The neural correlates of reinforcement sensitivity theory: A systematic review of the frontal asymmetry and spectral power literature

The original Reinforcement Sensitivity Theory (oRST) proposes two systems of approach (BAS) and avoidance (BIS) motivation to underpin personality and behavior. The revised-RST (rRST) model separates avoidance motivation into passive (BIS; anxiety) and active (FFFS; fear) systems. Prior research has attempted to map RST onto lateralized frontal asymmetry to provide a neurophysiological marker of RST. The main aim is to examine the relationships of the o/rRST scales with trait (baseline) and state (manipulated through experimental paradigms) frontal asymmetry. A systematic review was conducted, resulting in 158 studies designated to neuroimaging research. In total, 54 studies were included in this review using either frontal asymmetry or spectral power. The results were split into three main categories: resting frontal alpha asymmetry (N = 23), emotional induction and state-related frontal alpha asymmetry (N = 20), and spectral analysis (N = 16). Findings indicated that BAS was associated with enhanced left frontal asymmetry at baseline and during state-related paradigms. Findings for BIS were more inconsistent, especially at rest, suggesting that BIS, in particular, may require active engagement with the environment. Only 9 of the 54 papers included used the revised RST model, highlighting the need for more rRST research.

Is lack of goal-conflict-specific rhythmicity a biomarker for treatment resistance in generalised anxiety but not social anxiety or major depression?

BACKGROUND

Anxiety and depression cause major detriment to the patient, family, and society - particularly in treatment-resistant (TR) cases, which are highly prevalent. TR prevalence may be due to current diagnoses being based not on biological measures but on symptom lists that suffer from clinical subjectivity, variation in symptom presentation, and comorbidity.

AIMS

Goal-conflict-specific rhythmicity (GCSR) measured using the Stop-Signal Task (SST) may provide the first neural biomarker for an anxiety process and disorder. This GCSR has been validated with selective drugs for anxiety. So, we proposed that GCSR could differ between TR and non-TR individuals and do so differently between those diagnoses normally sensitive to selective anxiolytics and those not.

METHODS

We recorded electroencephalograms (EEG) from 20 TR participants (4 GAD, 5 SAD and 11 MDD) and 24 non-TR participants (4 GAD, 5 SAD and 15 Comorbid GAD/MDD (GMD)) while they performed the SST.

RESULTS

There was significant positive GCSR in all groups except the GAD-TR group. GAD-TR lacked GCSR in the low-frequency range. However, TR had little effect in SAD or MDD/GMD populations with apparent increases not decreases.

CONCLUSIONS

Overall, these results suggest that GAD may occur in two forms: one resulting from excessive GCSR and so being drug sensitive, and the other resulting from some other mechanism and so being TR. In SAD and MDD groups, heightened GCSR could be a consequence rather than the cause, driven by mechanisms that are normally more sensitive to non-selective panicolytic antidepressants.

How is variability in physiological responses to social stress related to punishment and reward sensitivities? Preliminary findings from the revised reinforcement sensitivity theory of personality perspective

OBJECTIVE

Although personality traits are assumed to have biological/physiological foundations, research has yielded mixed evidence regarding the relationship between personality and physiological stress responses. Moreover, the field has often overlooked the contemporary neuroscience-based personality approach, known as the Reinforcement Sensitivity Theory (RST) of Personality, in stress research.

METHOD

The present study examined the relationship between the revised RST's personality dimensions and heart rate and skin conductance level (SCL) in response to the Trier Social Stress Test in a sample of 61 healthy university students.

RESULTS

Piecewise latent growth curve analysis controlling for the participants' current life stress, smoking use, and caffeine intake revealed that individuals with higher behavioral inhibition exhibited higher physiological reactivity, whereas those with high reward sensitivity showed smaller heart rate reactivity. The behavioral disengagement facet of the behavioral inhibition scale was associated with reduced sympathetic arousal during the stress task. Additionally, reward interest was associated with a larger recovery of SCL.

CONCLUSION

Results were generally in line with the revised theory. The study findings were discussed within the paradigm of the approach-avoidance conflict and highlighted the importance of reward sensitivity in stress resilience.

Locus coeruleus noradrenaline depletion and its differential impact on CO2-induced panic and hyperventilation in male and female mice

CO2 exposure has been used to investigate the panicogenic response in patients with panic disorder. These patients are more sensitive to CO2, and more likely to experience the "false suffocation alarm" which triggers panic attacks. Imbalances in locus coeruleus noradrenergic (LC-NA) neurotransmission are responsible for psychiatric disorders, including panic disorder. These neurons are sensitive to changes in CO2/pH. Therefore, we investigated if LC-NA neurons are differentially activated after severe hypercapnia in mice. Further, we evaluated the participation of LC-NA neurons in ventilatory and panic-like escape responses induced by 20% CO2 in male and female wild type mice and two mouse models of altered LC-NA synthesis. Hypercapnia activates the LC-NA neurons, with males presenting a heightened level of activation. Mutant males lacking or with reduced LC-NA synthesis showed hypoventilation, while animals lacking LC noradrenaline present an increased metabolic rate compared to wild type in normocapnia. When exposed to CO2, males lacking LC noradrenaline showed a lower respiratory frequency compared to control animals. On the other hand, females lacking LC noradrenaline presented a higher tidal volume. Nevertheless, no change in ventilation was observed in either sex. CO2 evoked an active escape response. Mice lacking LC noradrenaline had a blunted jumping response and an increased freezing duration compared to the other groups. They also presented fewer racing episodes compared to wild type animals, but not different from mice with reduced LC noradrenaline. These findings suggest that LC-NA has an important role in ventilatory and panic-like escape responses elicited by CO2 exposure in mice.

The modulatory role of serotonin-1A receptors of the basolateral amygdala and dorsal periaqueductal gray on the impact of hormonal variation on the conditioned fear response

Despite significant advances in the study of fear and fear memory formation, little is known about fear learning and expression in females. This omission has been proven surprising, as normal and pathological behaviors are highly influenced by ovarian hormones, particularly estradiol and progesterone. In the current study, we investigated the joint influence of serotonin (5-HT) neurotransmission and estrous cycle phases (low or high levels of estradiol and progesterone) on the expression of conditioned fear in a group of female rats that were previously divided according to their response to stressful stimuli into low or high anxiety-like subjects. The baseline amplitude of the unconditioned acoustic startle responses was high in high-anxiety female rats, with no effect on the estrous cycle observed. Data collected during the proestrus-estrus phase revealed that low-anxiety rats had startle amplitudes similar to those of high-anxiety rats. It is supposed that high-anxiety female rats benefit from increased estradiol and progesterone levels to achieve comparable potentiated startle amplitudes. In contrast, female rats experienced a significant decrease in hormone levels during the Diestrus phase. This decrease is believed to play a role in preventing them from displaying a heightened startle response when faced with strongly aversive stimuli. Data collected after 5-HT and 8-OH-DPAT were administered into the basolateral nuclei and dorsal periaqueductal gray suggest that 5-HT neurotransmission works with progesterone and estrogen to reduce startle potentiation, most likely by activating the serotonin-1A receptor subtype.

Sensitivity to rewards and punishments in karate athletes: an examination of the temperamental characteristics and profile of karate competitors according to the revised reinforcement sensitivity theory

BACKGROUND

The revised Reinforcement Sensitivity Theory (rRST) assumes the existence of three systems controlling motivation and behavior: the behavioral activation system (BAS), the behavioral inhibition system (BIS), and the fight-flight-freeze system (FFFS). This study aims to examine for the first time the features of BAS, BIS, and FFFS among karate players in comparison with athletes representing other sports disciplines (physical education students) and physically inactive people. The specific configuration of temperament traits and profiles characterizing karate players will also be found.

METHODS

The cross-sectional study was performed among male karate athletes and control groups (physically active and inactive men). The study used the modified Reinforcement Sensitivity Questionnaire (rRSQ) to measure BAS, BIS, and FFFS.

RESULTS

The ANOVA showed that both karate competitors KS and KK scored significantly higher in BAS than the sample of PI participants. In addition, KK athletes scored significantly lower in Freeze than in PI and KS groups. Research also suggests that KK athletes presented significantly lower overall scores in FFFS than PI individuals. Furthermore, the results of K-means cluster analysis indicated the existence of two distinct patterns of temperamental traits: (1) Cluster 1 suggests avoidance tendencies (high Flight and Freeze, and low BAS, BIS, and Fight levels); while (2) the Cluster 2 describes approach tendencies (high BIS, BAS and Fight scores, and low levels of Flight and Freeze). Significantly more KK athletes were included in Cluster 2 than in Cluster 1, compared to PI, PA, and KS samples.

CONCLUSIONS

The research indicates that individuals engaged in karate, particularly those practicing Kyokushin karate, tend to exhibit a heightened sensitivity to rewards (high BAS). This finding holds significance for coaches and sports instructors, suggesting that motivating karate athletes through incentives is more effective, while the use of punishment should be minimized during training. Additionally, the study proposes that the practice of Kyokushin karate has the potential to significantly diminish the freezing response in threatening situations and enhance overall fear management by reducing levels of the Fight-Flight-Freeze System (FFFS). Consequently, the Kyokushin karate style may be considered more advantageous than the Karate Shotokan (KS) style in these aspects, despite both styles contributing to the improvement of BAS. Given that a higher BAS is linked to positive emotions, optimism, and happiness, karate training emerges as a form of health intervention, acting as a preventive measure against mental disorders and promoting overall well-being.

Locus of Control as a Mediator of the Relationships Between Motivational Systems and Trait Anxiety

The Reinforcement Sensitivity Theory, first proposed by Gray and later revised, describes three motivational systems: Behavioral Inhibition System (BIS), Behavioral Activation System (BAS), and Fight-Flight-Freeze System (FFFS). Studies have shown that high BIS and FFFS activation are positively related to anxiety symptoms, yet the relationship between BAS and anxiety remains unclear. Research data have also suggested that anxiety symptoms occur with the loss of perceived control. Thus, although studies on the direct effect of locus of control (LOC) on trait anxiety have accumulated for many years, the issue of how LOC may mediate the relationship between BIS/BAS/FFFS sensitivity and anxiety has not been addressed. This study aimed to explore the mediating role of LOC orientation on trait anxiety among young adults in association with these three motivational systems. Cross-sectional data were obtained from 422 volunteers. The BIS/BAS Scale, Trait Anxiety Inventory, and Rotter's Internal-External LOC Scale were applied. A series of mediation analyses were performed to estimate total, indirect, and direct effects. The results showed that BIS and FFFS positively predicted trait anxiety. In addition, LOC positively predicted trait anxiety and BIS. The results of the mediation analyses indicated that LOC functioned as a partial mediator between BIS and trait anxiety. This finding revealed that a high BIS level, one of the motivational systems, was associated with external LOC, which in turn contributed to reporting high trait anxiety in young adults. Hence, BIS and external LOC orientation could be suggested as risk factors for trait anxiety. As the external LOC orientation of individuals with high punishment sensitivity increased, their trait anxiety levels also increased. Therefore, it was suggested that it might be useful to be aware that LOC orientations of individuals with BIS sensitivity may pose a risk for trait anxiety.

Neural correlates of the revised reinforcement sensitivity theory: A cross-sectional structural neuroimaging study in middle-aged adults

The revised reinforcement sensitivity theory (RST) proposes that neurobiological systems control behavior: the fight-flight-freeze (FFFS) for avoidance of threat; behavioral approach/activation (BAS) for approach to rewards; and behavioral inhibition (BIS) for conflict resolution when avoidance and approach are possible. Neuroimaging studies have confirmed some theoretical associations between brain structures and the BAS and BIS; however, little representative population data are available for the FFFS. We investigated the neural correlates of the revised RST in a sample of 404 middle-aged adults (Mage = 47.18 (SD = 1.38); 54.5% female). Participants underwent structural magnetic resonance imaging and completed health questionnaires and the BIS/BAS/FFFS scales. We used multiple regression analyses to investigate the association between scale scores and volumes of a priori theoretically linked regions of interest while controlling for sex, age, intracranial volume, and cardio-metabolic variables; and conducted exploratory analyses on cortical thickness. The BIS was negatively associated with hippocampus laterality. At standard significance levels, the fear component of the FFFS was positively associated with anterior cingulate cortex; the BAS was positively associated with bilateral caudate; and the BIS was positively associated with posterior cingulate cortex volume. Furthermore, these neurobiological systems showed distinct patterns of association with cortical thickness though future work is needed. Our results showed that the neurobiological systems of the revised RST characterized in rodents can also be identified in the human brain.

Structural and functional disruption of subcortical limbic structures related with executive function in pediatric bipolar disorder

BACKGROUND

Impaired cognition has been demonstrated in pediatric bipolar disorder (PBD). The subcortical limbic structures play a key role in PBD. However, alternations of anatomical and functional characteristics of subcortical limbic structures and their relationship with neurocognition of PBD remain unclear.

METHODS

Thirty-six PBD type I (PBD-I) (15.36 ± 0.32 years old), twenty PBD type II (PBD-II) (14.80 ± 0.32 years old) and nineteen age-gender matched healthy controls (HCs) (14.16 ± 0.36 years old) were enlisted. Primarily, the volumes of the subcortical limbic structures were obtained and differences in the volumes were evaluated. Then, these structures served as seeds of regions of interest to calculate the voxel-wised functional connectivity (FC). After that, correlation analysis was completed between volumes and FC of brain regions showing significant differences and neuropsychological tests.

RESULTS

Compared to HCs, both PBD-I and PBD-II patients showed a decrease in the Stroop color word test (SCWT) and digit span backward test scores. Compared with HCs, PBD-II patients exhibited a significantly increased volume of right septal nuclei, and PBD-I patients presented increased FC of right nucleus accumbens and bilateral pallidum, of right basal forebrain with right putamen and left pallidum. Both the significantly altered volumes and FC were negatively correlated with SCWT scores.

SIGNIFICANCE

The study revealed the role of subcortical limbic structural and functional abnormalities on cognitive impairments in PBD patients. These may have far-reaching significance for the etiology of PBD and provide neuroimaging clues for the differential diagnosis of PBD subtypes.

CONCLUSIONS

Distinctive features of neural structure and function in PBD subtypes may contribute to better comprehending the potential mechanisms of PBD.

Cell-type-specific hypothalamic pathways to brainstem drive context-dependent strategies in response to stressors

Adaptive behavioral responses to stressors are critical for survival. However, which brain areas orchestrate switching the appropriate stress responses to distinct contexts is an open question. This study aimed to identify the cell-type-specific brain circuitry governing the selection of distinct behavioral strategies in response to stressors. Through novel mouse behavior paradigms, we observed distinct stressor-evoked behaviors in two psycho-spatially distinct contexts characterized by stressors inside or outside the safe zone. The identification of brain regions activated in both conditions revealed the involvement of the dorsomedial hypothalamus (DMH). Further investigation using optogenetics, chemogenetics, and photometry revealed that glutamatergic projections from the DMH to periaqueductal gray (PAG) mediated responses to inside stressors, while GABAergic projections, particularly from tachykinin1-expressing neurons, played a crucial role in coping with outside stressors. These findings elucidate the role of cell-type-specific circuitry from the DMH to the PAG in shaping behavioral strategies in response to stressors. These findings have the potential to advance our understanding of fundamental neurobiological processes and inform the development of novel approaches for managing context-dependent and anxiety-associated pathological conditions such as agoraphobia and claustrophobia.

Network Analysis of Behavioral Activation/Inhibition Systems and Brain Volume in Individuals With and Without Major Depressive Disorder or Social Anxiety Disorder

BACKGROUND

Social anxiety disorder (SAD) and major depressive disorder (MDD) are characterized by behavioral abnormalities in motivational systems, namely the behavioral inhibition system (BIS) and behavioral activation system (BAS). Limited studies indicate brain volume in regions that support emotion, learning/memory, reward, and cognitive functions relate to BIS/BAS. To increase understanding of BIS/BAS, the current study used a network approach.

METHODS

Patients with SAD (n = 59), patients with MDD (n = 64), and healthy control participants (n = 36) completed a BIS/BAS questionnaire and structural magnetic resonance imaging scans; volumetric regions of interest comprised cortical and limbic structures based on previous BIS/BAS studies. A Bayesian Gaussian graphical model was used for each diagnostic group, and groups were compared. Among network metrics, bridge centrality was of primary interest. Analysis of variance evaluated BIS/BAS behaviors between groups.

RESULTS

Bridge centrality showed hippocampus positively related to BAS, but not to BIS, in the MDD group; no findings were observed in the SAD or control groups. Yet, network density (i.e., overall strength of relationships between variables) and degree centrality (i.e., overall relationship between one variable to all other variables) showed that cortical (e.g., precuneus, medial orbitofrontal) and subcortical (e.g., amygdala, hippocampus) regions differed between diagnostic groups. Analysis of variance results showed BAS was lower in the MDD/SAD groups compared with the control group, while BIS was higher in the SAD group relative to the MDD group, which in turn was higher than the control group.

CONCLUSIONS

Preliminary findings indicate that network-level aberrations may underlie motivational abnormalities in MDD and SAD. Evidence of BIS/BAS differences builds on previous work that points to shared and distinct motivational differences in internalizing psychopathologies.

Acute stress promotes effort mobilization for safety-related goals

Although the acute stress response is a highly adaptive survival mechanism, much remains unknown about how its activation impacts our decisions and actions. Based on its resource-mobilizing function, here we hypothesize that this intricate psychophysiological process may increase the willingness (motivation) to engage in effortful, energy-consuming, actions. Across two experiments (n = 80, n = 84), participants exposed to a validated stress-induction protocol, compared to a no-stress control condition, exhibited an increased willingness to exert physical effort (grip force) in the service of avoiding the possibility of experiencing aversive electrical stimulation (threat-of-shock), but not for the acquisition of rewards (money). Use of computational cognitive models linked this observation to subjective value computations that prioritize safety over the minimization of effort expenditure; especially when facing unlikely threats that can only be neutralized via high levels of grip force. Taken together, these results suggest that activation of the acute stress response can selectively alter the willingness to exert effort for safety-related goals. These findings are relevant for understanding how, under stress, we become motivated to engage in effortful actions aimed at avoiding aversive outcomes.

A method for studying escape behavior to terrestrial threats in rodents

BACKGROUND

Escape is one of the most essential behaviors for an animal's survival because it could be a matter of life and death. Much of our current understanding of the neural mechanisms underlying escape is derived from the looming paradigm, which mimics a diving aerial predator. Yet, the idea of the looming paradigm does not account for all types of threats like lions hunting antelopes or cats stalking mice. Escape responses to such terrestrial threats may require different strategies and neural mechanisms.

NEW METHODS

Here, we developed a real-time interactive platform to study escape behavior to terrestrial threats in mice. A closed-loop controlled robot was magnetically pulled to mimic a terrestrial threat that chases a mouse. By using strong magnets and high-precision servo motors, the robot is capable of moving precisely with a high spatial-temporal resolution. Different algorithms can be used to achieve single approach or persistent approach.

RESULTS

Animal experiments showed that mice exhibited consistent escape behavior when exposed to an approaching robotic predator. When presented with a persistently approaching predator, the mice were able to rapidly adapt their behavior, as evidenced by a decrease in startle responses and changes in movement patterns.

COMPARISON WITH EXISTING METHODS

In comparison to existing methods for studying escape behavior, such as the looming paradigm, this approach is more suitable for investigating animal behavior in response to sustained threats.

CONCLUSION

In conclusion, we have developed a flexible platform to study escape behavior to terrestrial threats in mice.

Leveraging interindividual variability in threat conditioning of inbred mice to model trait anxiety

Trait anxiety is a major risk factor for stress-induced and anxiety disorders in humans. However, animal models accounting for the interindividual variability in stress vulnerability are largely lacking. Moreover, the pervasive bias of using mostly male animals in preclinical studies poorly reflects the increased prevalence of psychiatric disorders in women. Using the threat imminence continuum theory, we designed and validated an auditory aversive conditioning-based pipeline in both female and male mice. We operationalised trait anxiety by harnessing the naturally occurring variability of defensive freezing responses combined with a model-based clustering strategy. While sustained freezing during prolonged retrieval sessions was identified as an anxiety-endophenotype behavioral marker in both sexes, females were consistently associated with an increased freezing response. RNA-sequencing of CeA, BLA, ACC, and BNST revealed massive differences in phasic and sustained responders' transcriptomes, correlating with transcriptomic signatures of psychiatric disorders, particularly post-traumatic stress disorder (PTSD). Moreover, we detected significant alterations in the excitation/inhibition balance of principal neurons in the lateral amygdala. These findings provide compelling evidence that trait anxiety in inbred mice can be leveraged to develop translationally relevant preclinical models to investigate mechanisms of stress susceptibility in a sex-specific manner.

Rodent tests of depression and anxiety: Construct validity and translational relevance

Behavioral testing constitutes the primary method to measure the emotional states of nonhuman animals in preclinical research. Emerging as the characteristic tool of the behaviorist school of psychology, behavioral testing of animals, particularly rodents, is employed to understand the complex cognitive and affective symptoms of neuropsychiatric disorders. Following the symptom-based diagnosis model of the DSM, rodent models and tests of depression and anxiety focus on behavioral patterns that resemble the superficial symptoms of these disorders. While these practices provided researchers with a platform to screen novel antidepressant and anxiolytic drug candidates, their construct validity-involving relevant underlying mechanisms-has been questioned. In this review, we present the laboratory procedures used to assess depressive- and anxiety-like behaviors in rats and mice. These include constructs that rely on stress-triggered responses, such as behavioral despair, and those that emerge with nonaversive training, such as cognitive bias. We describe the specific behavioral tests that are used to assess these constructs and discuss the criticisms on their theoretical background. We review specific concerns about the construct validity and translational relevance of individual behavioral tests, outline the limitations of the traditional, symptom-based interpretation, and introduce novel, ethologically relevant frameworks that emphasize simple behavioral patterns. Finally, we explore behavioral monitoring and morphological analysis methods that can be integrated into behavioral testing and discuss how they can enhance the construct validity of these tests.

Psychometric properties of the Persian version of the Reinforcement Sensitivity Theory Personality Questionnaire (RST-PQ)

BACKGROUND

The Reinforcement Sensitivity Theory of Personality Questionnaire (RST-PQ) originated from the Revised Reinforcement Sensitivity Theory of Personality. This study was conducted to assess the psychometric properties of the Persian version of the RST-PQ among a group of Iranian adults.

METHOD

The cross-sectional study was carried out among 600 Iranian adults utilizing a convenient sampling method, following specific participant selection criteria to enhance the study methodology's transparency (including the age range between 18 and 35 years' participants without major psychiatric diagnoses). Participants completed both the Iranian version of the Reinforcement Sensitivity Theory Personality Questionnaire (RST-PQ) and the Five-Factor NEO-FFI questionnaire. Confirmatory factor analysis, employing the multiple indicators model (MIMIC) approach, was utilized in this study to control for demographic variables such as age and gender.

RESULTS

The confirmatory factor analysis results showed an acceptable fit of the proposed six-factor model based on the English version of RST-PQ (CFI = 0.905; RMSEA = 0.053). Also, Cronbach's alpha values confirmed the internal consistency of the proposed structure. In addition, competing models were also used to select the best-proposed model. In this way, different models were evaluated, assuming a change in the correlation intensity between BIS and the Fight-Flight-Freeze System (FFFS).

CONCLUSIONS

The convergent validity results with the Five-Factor Personality measure provided further support and were consistent with previous research findings. It is crucial to have an Iranian-language version of the RST-PQ to promote RST research and show how this theoretical framework aids in explaining and predicting various actions, whether they are abnormal or healthy.

The Effect of Induced Regulatory Focus on Frontal Cortical Activity

The motivation-direction model has served as the primary framework for understanding frontal cortical activity. However, research on the link between approach/avoidance motivation and left/right frontal cortical activity has produced inconsistent findings. Recent studies suggest that regulatory systems may offer a more accurate explanation than the motivational direction model. Despite being regulatory systems, the relationship between regulatory focus and frontal cortical activity has received limited attention. Only one experimental study has explored this connection through correlational analysis, yet it lacks causal evidence. The present study aimed to address this gap by manipulating regulatory focus and measuring frontal cortical activity in 36 college students. Our results revealed that induced promotion focus led to increased left frontal cortical activity, whereas induced prevention focus led to increased right frontal cortical activity. These findings enhance our physiological understanding of regulatory focus and offer a deeper explanation of how regulatory focus influences alterations in psychology and behavior.

Developing a mental toughness program for basic military training

To build a warfighter from the ground up, training should include not only the core competencies required for job performance in the Fleet but also the mental toughness expected to handle the stress, fatigue, and call for sudden action required of all sailors on duty, regardless of occupation. Recruit Training Command (RTC) has embarked on a program to provide explicit training to recruits on the development of toughness in boot camp. This program is multifaceted, including three pilot programs (two all-male pilots, one integrated/mixed gender pilot) for mental skill training. Recruit divisions were assigned to either mental toughness (MT) condition or active control (AC). The MT group received daily, 10-min guided mindfulness exercises, three "just-in-time" trainings in sports psychology skills, and an on-command focusing exercise. Results varied across the three pilots with the exception of on-time graduation rates, which favored the MT condition in every pilot. Taken together, the three MT pilot studies show possible benefits for performance during boot camp with MT practice, and predictable advantages for graduation rates.

Exploring Brainstem Structural Abnormalities: Potential Biomarkers for Panic Disorder

Panic disorder (PD), characterized by recurrent and intense panic attacks, presents a complex interplay between psychological and neurobiological factors. Although the amygdala and hippocampus have been studied extensively in the context of PD, the brainstem's involvement remains relatively underexplored. This study aims to address this gap by examining structural abnormalities within specific brainstem regions, including the medulla, pons, and midbrain. The study sample population comprised twenty-one adult patients diagnosed with PD and an age-gender-education-matched control group. Utilizing rigorous inclusion and exclusion criteria, confounding factors related to comorbid psychiatric conditions and brain structure abnormalities were minimized. Our findings revealed a significant reduction in medulla volume among PD patients, a finding that persisted even after correcting for individual differences in total intracranial volume. The medulla's role in cardiovascular regulation and autonomic function, coupled with its involvement in fear responses, underscores its potential significance in the pathophysiology of PD. This study elucidates the medulla's structural abnormalities as a potential biomarker for PD. Understanding the role of the brainstem in PD could pave the way for more targeted and effective interventions for this condition.

Emotion regulation effects of Ayahuasca in experienced subjects during implicit aversive stimulation: An fMRI study

ETHNOPHARMACOLOGICAL RELEVANCE

Ayahuasca is a beverage used in Amazonian traditional medicine and it has been part of the human experience for millennia as well as other different psychoactive plants. Although Ayahuasca has been proposed as potentially therapeutic as an anxiolytic and antidepressant, whilst no studies have been carried out so far investigating their direct effect on brain emotional processing.

AIM OF THE STUDY

This study aimed to measure the emotional acute effect of Ayahuasca on brain response to implicit aversive stimulation using a face recognition task in functional magnetic resonance imaging (fMRI).

MATERIALS AND METHODS

Nineteen male experienced Ayahuasca users participated in this study in two fMRI sessions before and after 50 min of the Ayahuasca ingestion. Subjects were presented with pictures of neutral (A) and aversive (B) (fearful or disgusted) faces from the Pictures of Facial Affect Series. Subjects were instructed to identify the gender of the faces (gender discrimination task) while the emotional content was implicit. Subjective mood states were also evaluated before Ayahuasca intake and after the second fMRI session, using a visual analogue mood scale (VAMS).

RESULTS

During the aversive stimuli, the activity in the bilateral amygdala was attenuated by Ayahuasca (qFDR<0.05). Furthermore, in an exploratory analysis of the effects after intake, Ayahuasca enhances the activation in the insular cortex bilaterally, as well as in the right dorsolateral prefrontal cortex (qFDR<0.05). In the psychometric VAMS scale, subjects reported attenuation of both anxiety and mental sedation (p < 0.01) during acute effects.

CONCLUSIONS

Together, all reported results including neuroimaging, behavioral data and psychometric self-report suggest that Ayahuasca can promote an emotion regulation mechanism in response to aversive stimuli with corresponding improved cognition including reduced anxiety and mental sedation.

Decoding the language of fear: Unveiling objective and subjective indicators in rodent models through a systematic review and meta-analysis

While rodent models are vital for studying mental disorders, the underestimation of construct validity of fear indicators has led to limitations in translating to effective clinical treatments. Addressing this gap, we systematically reviewed 5054 articles from the 1960 s, understanding underlying theoretical advancement, and selected 68 articles with at least two fear indicators for a three-level meta-analysis. We hypothesized correlations between different indicators would elucidate similar functions, while magnitude differences could reveal distinct neural or behavioral mechanisms. Our findings reveal a shift towards using freezing behavior as the primary fear indicator in rodent models, and strong, moderate, and weak correlations between freezing and conditioned suppression ratios, 22-kHz ultrasonic vocalizations, and autonomic nervous system responses, respectively. Using freezing as a reference, moderator analysis shows treatment types and fear stages significantly influenced differences in magnitudes between two indicators. Our analysis supports a two-system model of fear in rodents, where objective and subjective fears could operate on a threshold-based mechanism.

The Neural Correlates of Individual Differences in Reinforcement Learning during Pain Avoidance and Reward Seeking

Organisms learn to gain reward and avoid punishment through action-outcome associations. Reinforcement learning (RL) offers a critical framework to understand individual differences in this associative learning by assessing learning rate, action bias, pavlovian factor (i.e., the extent to which action values are influenced by stimulus values), and subjective impact of outcomes (i.e., motivation to seek reward and avoid punishment). Nevertheless, how these individual-level metrics are represented in the brain remains unclear. The current study leveraged fMRI in healthy humans and a probabilistic learning go/no-go task to characterize the neural correlates involved in learning to seek reward and avoid pain. Behaviorally, participants showed a higher learning rate during pain avoidance relative to reward seeking. Additionally, the subjective impact of outcomes was greater for reward trials and associated with lower response randomness. Our imaging findings showed that individual differences in learning rate and performance accuracy during avoidance learning were positively associated with activities of the dorsal anterior cingulate cortex, midcingulate cortex, and postcentral gyrus. In contrast, the pavlovian factor was represented in the precentral gyrus and superior frontal gyrus (SFG) during pain avoidance and reward seeking, respectively. Individual variation of the subjective impact of outcomes was positively predicted by activation of the left posterior cingulate cortex. Finally, action bias was represented by the supplementary motor area (SMA) and pre-SMA whereas the SFG played a role in restraining this action tendency. Together, these findings highlight for the first time the neural substrates of individual differences in the computational processes during RL.

Attentional bias to threat is modulated by stimulus content: an fNIRS study

People are evolutionarily predisposed to associate threat relevant stimuli with fear or aversiveness and show an attentional bias toward threat. Attentional bias modification (ABM) has been shown to reduce threat biases, while quantitative reviews assessing the effectiveness of bias modification yielded inconsistent results. The current study examined the relationship between the training effect of attentional bias to threat and the type of threatening stimuli. Twenty-two participants performed a modified dot-probe task while undergoing functional near-infrared spectroscopy (fNIRS) imaging. Results indicated that there was a strong pattern of attentional avoidance among individuals in an animal but not human threat condition. Furthermore, findings from fNIRS confirmed that the influence from type of threatening stimulus would be modulated by cortical activation patterns, especially in the ventrolateral prefrontal cortices (vlPFC) and angular gyrus. Overall, these results suggest that stimulus-specific may play a major role in personalization of specific psychological interventions.

Lateral hypothalamic glutamatergic inputs to VTA glutamatergic neurons mediate prioritization of innate defensive behavior over feeding

The lateral hypothalamus (LH) is involved in feeding behavior and defense responses by interacting with different brain structures, including the Ventral Tegmental Area (VTA). Emerging evidence indicates that LH-glutamatergic neurons infrequently synapse on VTA-dopamine neurons but preferentially establish multiple synapses on VTA-glutamatergic neurons. Here, we demonstrated that LH-glutamatergic inputs to VTA promoted active avoidance, long-term aversion, and escape attempts. By testing feeding in the presence of a predator, we observed that ongoing feeding was decreased, and that this predator-induced decrease in feeding was abolished by photoinhibition of the LH-glutamatergic inputs to VTA. By VTA specific neuronal ablation, we established that predator-induced decreases in feeding were mediated by VTA-glutamatergic neurons but not by dopamine or GABA neurons. Thus, we provided evidence for an unanticipated neuronal circuitry between LH-glutamatergic inputs to VTA-glutamatergic neurons that plays a role in prioritizing escape, and in the switch from feeding to escape in mice.

Differential behavioral response to predator odor in neuropathic pain in mice

Neuropathic pain, a type of chronic pain caused by injury or disease of the somatosensory system, affects ∼10% of the general population and is difficult to treat. It is strongly associated with mood disorder comorbidities and impairs quality of life. It was recently suggested that hypervigilance caused by chronic pain might be of advantage in some species, helping them avoid predators during injury when they are most vulnerable. Here, we sought to confirm the hypervigilance hypothesis by using two predator odor (PO) paradigms, one with transient and one with continuous odor presentation. We observed behavioral responses to PO in neuropathic and control mice in an open field setting. We find that neuropathic mice show hypervigilance to PO, confirming previous results. However, we also find increased anxiety responses to neutral odor in neuropathic mice, which manifests as maladaptive pain. This demonstrates that this maladaptive nature of pain could be an evolutionary adaptation aimed at reducing injury-induced vulnerability.

Hand-blink reflex modulation: The role of primary emotions and attachment dimensions

The hand-blink reflex (HBR) is a subcortical response elicited by the electrical stimulation of the median nerve. HBR magnitude is enhanced when the stimulated hand is close to the face and is modulated by high-level structures according to the perceived threat magnitude. Psychological factors may contribute to threat evaluation and possibly to HBR amplitude modulation. In this study, we assessed distinctively emotional and relational aspects of personality and evaluated their associations with the HBR response, or lack thereof, in healthy subjects. Seventy-one volunteers filled the Experiences in Close Relationships Scale, the Affective Neuroscience Personality Scales, and the State-Trait Anxiety Inventory Form Y questionnaires and underwent HBR recording. We found that the HBR could be evoked only in 50.7% of all subjects (responders). Non-responders subjects showed higher scores in the avoidance dimension (p = .005), and lower scores in the care dimension (p = .008), compared with responders. In responders, regression analysis showed a negative association of HBR amplitude (difference in near vs. far responses) with anger dimension and a positive association with state anxiety (R2  = 0.239). A positive association also emerged with HBR latency and fear dimension (R2  = 0.419). We conclude that primary emotional and relational factors may play an important role in the modulation of brainstem circuits mediating the HBR response. Our results may also contribute to the question about the absence of the HBR in about half of the subjects since high-level cognitive processes seem to play an important role in the differentiation between responder and non-responder.

An examination of frontal asymmetry in relation to eating in the absence of hunger and loss-of-control eating

Loss-of-control (LOC) eating involves a subjective feeling that one cannot stop eating or control one's eating. Individuals with LOC eating may exhibit strong appetitive drives and weak inhibitory control, and these two opposing motivations have been related to EEG measurements of frontal asymmetry or lateralized frontal activation. The present study investigated whether frontal asymmetry is related to hedonic hunger, LOC eating severity and frequency, and eating in the absence of hunger (EAH) in the laboratory. Fifty-nine individuals participated in an ostensible taste study after resting-state electroencephalogram (EEG) recordings. After the EEGs, they were provided a meal to eat until fullness, followed by an array of snacks and instructions to eat as much as they would like. The results indicated that several measures of right-frontal asymmetry were related to greater EAH and greater self-reported LOC eating severity. Although right-frontal asymmetry has been theorized to reflect avoidance motivation, recent evidence suggests it may indicate effortful control during approach-avoidance conflicts. Because individuals with LOC eating presumably experience heightened conflict between drives to eat beyond energy needs and to minimize such eating, those experiencing greater LOC may exert greater effort to manage these conflicting motivations. An integration of these neurobiological correlates of LOC eating may help provide a more comprehensive understanding of LOC eating and inform treatments.

Contribution of the Roman rat lines/strains to personality neuroscience: neurobehavioral modeling of internalizing/externalizing psychopathologies

The Roman high-avoidance (RHA) and low-avoidance (RLA) rat lines/strains were established in Rome through bidirectional selection of Wistar rats for rapid (RHA) or extremely poor (RLA) acquisition of a two-way active avoidance task. Relative to RHAs, RLA rats exhibit enhanced threat sensitivity, anxiety, fear and vulnerability to stress, a passive coping style and increased sensitivity to frustration. Thus, RLA rats' phenotypic profile falls well within the "internalizing" behavior spectrum. Compared with RLAs and other rat strains/stocks, RHAs present increased impulsivity and reward sensitivity, deficits in social behavior and attentional/cognitive processes, novelty-induced hyper-locomotion and vulnerability to psychostimulant sensitization and drug addiction. Thus, RHA rats' phenotypes are consistent with a "disinhibiting externalizing" profile. Many neurobiological/molecular traits differentiate both rat lines/strains. For example, relative to RLA rats, RHAs exhibit decreased function of the prefrontal cortex (PFC), hippocampus and amygdala, increased functional tone of the mesolimbic dopamine system, a deficit of central metabotropic glutamate-2 (mGlu2) receptors, increased density of serotonin 5-HT2A receptors in the PFC, impairment of GABAergic transmission in the PFC, alterations of several synaptic markers and increased density of pyramidal immature dendrític spines in the PFC. These characteristics suggest an immature brain of RHA rats and are reminiscent of schizophrenia features like hypofrontality and disruption of the excitation/inhibition cortical balance. We review evidence supporting RLA rats as a valid model of anxiety/fear, stress and frustration vulnerability, whereas RHA rats represent a promising translational model of neurodevelopmental alterations related to impulsivity, schizophrenia-relevant features and comorbidity with drug addiction vulnerability.

Exploring behavioral systems of the reinforcement sensitivity theory in people with epilepsy: A cross-sectional study

OBJECTIVES

Although epilepsy has previously been associated with behavioral changes, no previous study has utilized the behavioral models of the reinforcement sensitivity theory (RST) to investigate the impact of epilepsy on behavior. Therefore, the objective of this cross-sectional study is to examine the potential relationship between epilepsy and the neurobehavioral systems of the RST.

METHODS

Using the Reinforcement Sensitivity Theory-Personality Questionnaire (RST-PQ), this cross-sectional study assessed the behavioral systems of the RST in a sample of 27 epilepsy patients and 27 age- and gender-matched healthy individuals. The RST-PQ was designed to assess the different behavioral systems of the RST. The behavioral approach system (BAS) is responsible of the approach behavior, in high values related to risk seeking and addictive behavior and in low values well related to depression. The behavioral inhibition system (BIS) is well related to anxiety in high levels, and the fight flight freeze system (FFFS) is responsible for the avoidance behavior.

RESULTS

After adjusting for age, no significant differences were found in demographic information (gender and marital status) between the general population and epilepsy patients. Gender distribution was similar, with 55.6% females in both groups. Marital status also showed no significant difference, with 74% single in the control group and 63% in the epilepsy group. Significant differences were observed in the behavioral systems of the RST. The epilepsy group had higher scores compared with the control group in several areas. BAS reward activity had a median score of 23 in the epilepsy group and 21 in the control group (p = 0.001). BAS goal drive persistence (p = 0.04), BAS impulsivity (p = 0.014), FFFS (p = 0.002), and BIS (median score of 77 in the epilepsy group and 66 in the control group) also showed significant differences, with p = 0.001. These significant differences remained consistent before and after matching the control group, indicating their robustness. The only exception was BAS reward activity, which did not show a significant difference after matching, with p = 0.106 and p = 0.051 before and after matching, respectively.

CONCLUSIONS

The study suggests a potential positive association between epilepsy and the BIS, potentially mediated by the hippocampus. The relationship between epilepsy and the BAS, as well as the FFFS, may also be influenced by the BIS. These findings have clinical implications, but further research is needed to confirm these relationships.

Transdiagnostic phenomena of psychopathology in the context of the RDoC: protocol of a multimodal cross-sectional study

In the past, affective and cognitive processes related to psychopathology have been examined within the boundaries of phenotype-based diagnostic labels, which has led to inconsistent findings regarding their underlying operating principles. Investigating these processes dimensionally in healthy individuals and by means of multiple modalities may provide additional insights into the psychological and neuronal mechanisms at their core. The transdiagnostic phenomena Neuroticism and Rumination are known to be closely linked. However, the exact nature of their relationship remains to be elucidated. The same applies to the associations between Hedonic Capacity, Negativity Bias and different Emotion Regulation strategies.This multimodal cross-sectional study examines the relationship of the transdiagnostic phenomena Neuroticism and Rumination as well as Hedonic Capacity, the Negativity Bias and Emotion Regulation from a RDoC (Research Domain Criteria) perspective. A total of 120 currently healthy subjects (past 12 months) will complete several questionnaires regarding personality, emotion regulation, hedonic capacity, and psychopathologies as well as functional magnetic resonance imaging (fMRI) during cognitive and emotional processing, to obtain data on the circuit, behavioral and self-report level.This study aims to contribute to the understanding of the relationship between cognitive and affective processes associated with psychopathologies as well as their neuronal correlates. Ultimately, a grounded understanding of these processes could guide improvement of diagnostic labels and treatments. Limitations include the cross-sectional design and the limited variability in psychopathology scores due to the restriction of the sample to currently healthy subjects.

c-Fos expression after neonatal handling in social brain regions: Distinctive profile of RHA-rat schizophrenia model on a social preference test

Neonatal handling (NH) is an environmental manipulation that induces long-lasting changes in behavioural, neuroendocrine, and neuroanatomical processes in rodents. We have previously reported that NH treatment increases social interaction preference in an animal model of schizophrenia-relevant features, the Roman high-avoidance (RHA) rats. The present study was aimed at evaluating whether the increase of social behaviour/preference due to NH treatment in RHA rats is associated with differences in c-Fos expression levels in some of the brain areas that integrate the "social brain". To this aim, we evaluated the performance of adult male rats from both Roman rat strains (RHA vs. RLA -Roman low-avoidance- rats), either untreated (control) or treated with NH (administered during the first 21 days of life) in a social interaction task. For the analyses of c-Fos activation untreated and NH-treated animals were divided into three different experimental conditions: undisturbed home cage controls (HC); rats exposed to the testing set-up context (CTX); and rats exposed to a social interaction (SI) test. It was found that, compared with their RLA counterparts, NH treatment increased social behaviour in RHA rats, and also specifically enhanced c-Fos expression in RHA rats tested for SI in some brain areas related to social behaviour, i.e. the infralimbic cortex (IL) and the medial posterodorsal amygdala (MePD) regions.

Unwinding the potentials of vitamin C in COVID-19 and other diseases: An updated review

Background: The discovery of vitamin C (ascorbic acid) is related to the ancient history of persistent research on the origins of the haemorrhagic disease scurvy. Vitamin C is an important nutrient that aids in a variety of biological and physiological processes. Scientists have been researching the function of vitamin C in the prevention and ailment of sepsis and pneumonia for decades. This has created a potential platform for applying these results to individuals suffering from severe coronavirus infection (COVID-19). Vitamin C's ability to activate and enhance the immune system makes it a promising treatment in the present COVID-19 pandemic. Vitamin C also aids in the activation of vitamin B, the production of certain neurotransmitters, and the transformation of cholesterol into bile acids. Hence, vitamin C is used for the treatment of many diseases. Aim: This review highlights the Vitamin C investigations that are performed by various researchers on patients with COVID 19 infection, the clinical studies and their observations. The authors have additionally updated information on the significance of vitamin C insufficiency, as well as its relevance and involvement in diseases such as cancer, wound healing, iron deficiency anaemia, atherosclerosis and neurodegenerative disorders. Here, we discuss them with the references. Methods: The method used in order to perform literature search was done using SciFinder, PubMed and ScienceDirect. Results: There is a potential role of vitamin C in various diseases including neurodegenerative disorders, COVID-19 and other diseases and the results are highlighted in the review with the help of clinical and preclinical data. Conclusion: More research on vitamin C and the undergoing clinical trials might prove a potential role of vitamin C in protecting the population from current COVID-19 pandemic.

Copeptin response to panic provocation with CO2 in healthy adults

Repeated panic attacks are the core symptom of panic disorder and severely stressful for patients. Additional to the psychological response, the physiological symptoms are an important aspect of the experienced panic. However, data on the extent of hypothalamic-pituitary-adrenal (HPA)-axis activation during panic attacks is inconsistent. Therefore, in the present study, we aimed at investigating the stress-axis activity in more detail by including Copeptin (CoP) as a stable surrogate parameter for the vasopressinergic hypothalamic activity during experimentally induced panic attacks in healthy adults (N = 21). During a placebo-controlled panic challenge with 35% CO2 compared to normal air inhalation, we measured CoP and the peripheral effector hormones Adrenocorticotropic Releasing Hormone (ACTH) and cortisol in plasma along with the psychological response to panic anxiety. We analyzed hormonal secretion patterns, their correlations and individual panic ratings over time and explored differences between female and male participants. We found a significant CO2-induced increase of CoP plasma levels and psychological panic symptoms after CO2-administration, while no positive correlations of CoP levels with the peripheral HPA-axis hormones and with panic symptoms were present. No differences between female and male participants concerning their psychological response nor their baseline CoP levels, the release of CoP or its increase during the experiment were found. CoP could be a sensitive indicator for an organism's physiologic acute hypothalamic response during stress and panic attacks.

Understanding anxiety symptoms as aberrant defensive responding along the threat imminence continuum

Threat-anticipatory defensive responses have evolved to promote survival in a dynamic world. While inherently adaptive, aberrant expression of defensive responses to potential threat could manifest as pathological anxiety, which is prevalent, impairing, and associated with adverse outcomes. Extensive translational neuroscience research indicates that normative defensive responses are organized by threat imminence, such that distinct response patterns are observed in each phase of threat encounter and orchestrated by partially conserved neural circuitry. Anxiety symptoms, such as excessive and pervasive worry, physiological arousal, and avoidance behavior, may reflect aberrant expression of otherwise normative defensive responses, and therefore follow the same imminence-based organization. Here, empirical evidence linking aberrant expression of specific, imminence-dependent defensive responding to distinct anxiety symptoms is reviewed, and plausible contributing neural circuitry is highlighted. Drawing from translational and clinical research, the proposed framework informs our understanding of pathological anxiety by grounding anxiety symptoms in conserved psychobiological mechanisms. Potential implications for research and treatment are discussed.

The effects of hydrocortisone and yohimbine on human behavior in approach-avoidance conflicts

RATIONALE

Balancing approach of positive and avoidance of negative stimuli is essential when faced with approach-avoidance conflicts, e.g., situations with both positive and negative outcomes. This balance is disturbed in several mental disorders, e.g., excessive avoidance in anxiety disorders, and heightened approach in substance use disorders. Since stress is assumed to impact these disorders' etiology and maintenance, it seems crucial to understand how stress influences behavior in approach-avoidance conflicts. Indeed, some studies suggested altered approach-avoidance behavior under acute stress, but the mechanism underlying these effects is unknown.

OBJECTIVES

Investigate how the pharmacological manipulation of major stress mediators (cortisol and noradrenaline) influences task-based approach-avoidance conflict behavior in healthy individuals.

METHODS

Ninety-six participants (48 women, 48 men) received either 20mg hydrocortisone, 20mg yohimbine, both, or placebo before performing a task targeting foraging under predation in a fully crossed double-blind between-subject design. Moreover, we investigated effects of gender and endogenous testosterone and estradiol levels on approach-avoidance behavior.

RESULTS

While biological stress markers (cortisol concentration, alpha amylase activity) indicated successful pharmacological manipulation, behavior in approach-avoidance conflicts was not affected as expected. Although yohimbine administration affected risky foraging latency under predation, we found no main effect of hydrocortisone or their interaction on behavior. In contrast, we found gender differences for almost all behavioral outcome measures, which might be explained by differences in endogenous testosterone levels.

CONCLUSIONS

The investigated major stress mediators were not sufficient to imitate previously shown stress effects on approach-avoidance conflict behavior. We discuss potential reasons for our findings and implications for future research.

The nature and neurobiology of fear and anxiety: State of the science and opportunities for accelerating discovery

Fear and anxiety play a central role in mammalian life, and there is considerable interest in clarifying their nature, identifying their biological underpinnings, and determining their consequences for health and disease. Here we provide a roundtable discussion on the nature and biological bases of fear- and anxiety-related states, traits, and disorders. The discussants include scientists familiar with a wide variety of populations and a broad spectrum of techniques. The goal of the roundtable was to take stock of the state of the science and provide a roadmap to the next generation of fear and anxiety research. Much of the discussion centered on the key challenges facing the field, the most fruitful avenues for future research, and emerging opportunities for accelerating discovery, with implications for scientists, funders, and other stakeholders. Understanding fear and anxiety is a matter of practical importance. Anxiety disorders are a leading burden on public health and existing treatments are far from curative, underscoring the urgency of developing a deeper understanding of the factors governing threat-related emotions.

Exploring Response Inhibition, the Behavioral Inhibition System and Possible Sex Differences in Athletes and Non-Athletes

BACKGROUND

The objective of this study was to revisit the question concerning whether athletes are better than non-athletes at fundamental cognitive abilities, such as inhibitory control, in addition to also focusing on motivational dispositions and possible sex differences. Adding the latter could be crucial since both inhibitory control and motivational dispositions, such as approach and avoidance, are central to goal-directed behavior.

METHODS

This study's sample was composed of 93 participants (40 males): 29 biathletes; 30 alpine skiers; and 34 non-athletes. A non-sport-specific stop-signal task was used for the assessment of inhibitory control in terms of response inhibition, and the motivational dispositions were assessed with the BIS/BAS scales.

RESULTS

The results showed that there were no differences between the two different sports or non-athletes with regard to response inhibition. However, females showed significantly slower response inhibition than males (p = 0.018) and scored significantly higher on the trait variable BIS (p < 0.001).

CONCLUSIONS

The results from this study suggest that it might be meaningful to explore the contribution of sex differences and motivational dispositions on response inhibition in conjunction with different types of sports.

The German version of the brief affective neuroscience personality scales including a LUST scale (BANPS-GL)

Objectives

This study presents the German version of the Brief Affective Neuroscience Personality Scales (BANPS), which includes an additional subscale for the dimension LUST. The BANPS represents a shortened version of the Affective Neuroscience Personality Scales (ANPS), a self-report instrument to assess individual dispositions toward primary emotional systems as proposed by Jaak Panksepp.

Methods

In a large sample (N = 926), the reliability and various facets of validity of the German translation of the BANPS were examined together with the newly included LUST scale. The BANPS-GL was related to the Big Five Inventory (BFI) and Sexual Sensation Seeking Scale (SSSS) and analyzed via confirmatory factor analysis (CFA).

Results

Overall, the BANPS-GL exhibited reliabilities ranging from McDonald's ω = 0.70 (CARE) to α = 0.86 (SADNESS) and plausible correlations with external criteria. For CFA a correlated 7-factor model demonstrated good fit [TLI = 0.95; RMSEA = 0.04 (90% CI: 0.04, 0.05); SRMR = 0.06]. A similar fit was demonstrated for a 2-higher-factor model [TLI = 0.93; RMSEA = 0.05 (90% CI: 0.05, 0.06); SRMR = 0.07].

Conclusion

In broad agreement with the results of the original English version, the BANPS-GL showed good reliability and acceptable factorial validity, and overall improved the psychometric properties of the original long form. Finally, the inclusion of the dimension LUST allows for a complete coverage of the primary emotion dispositions as originally conceptualized by Panksepp.

The domain-variant indirect association between electrophysiological response to reward and ADHD presentations is moderated by dopaminergic polymorphisms

BACKGROUND

Understanding the etiopathogenesis of attention-deficit/hyperactivity disorder (ADHD) may necessitate decomposition of the heterogeneous clinical phenotype into more homogeneous intermediate phenotypes. Reinforcement sensitivity is a promising candidate, but the exact nature of the ADHD-reward relation - including how, for whom, and to which ADHD dimensions atypicalities in reward processing are relevant - is equivocal.

METHODS

Aims were to examine, in a carefully phenotyped sample of adolescents (N = 305; Mage = 15.30 years, SD = 1.07; 39.7% girls), whether functional dopaminergic polymorphisms implicated in both reward processing and ADHD (1) are differentially associated with event-related potentials (ERPs) of reward anticipation at distinct levels of ADHD risk (nno risk = 174, nat-risk = 131, ndiagnosed = 83); and (2) moderate the indirect effect of dispositional affectivity on the association between ERPs and ADHD domains.

RESULTS

In adolescents at-risk for or with ADHD, carrying a hypodopaminergic allele was associated with enhanced ERPs of attention allocation to cue and attenuated ERPs of anticipatory attention to feedback. No associations were observed in adolescents not at-risk for or without ADHD. Controlling for age and sex, both the negative indirect effect of positive affectivity (PA) on the association between ERPs and inattention and the positive indirect effect of PA on the association between ERPs and hyperactivity/impulsivity were supported only for those with high activity dopamine transporter (DAT) alleles.

CONCLUSIONS

Reward and affective processing are promising intermediate phenotypes relevant to disentangling ADHD developmental pathways. Consistent with developmental multifinality, through the successive effects of reward anticipation and positive affectivity, functional dopaminergic variants may confer protection against inattention or risk for hyperactivity/impulsivity.

Neurodevelopmental Model Explaining Associations between Sex Hormones, Personality, and Eating Pathology

Clinical scientists have been investigating the relationships between sex hormones, personality, and eating disorders for decades. However, there is a lack of direct research that addresses whether personality mediates or moderates the relationships between sex hormones and eating pathology. Moreover, the neural mechanisms that underlie the interactive associations between these variables remain unclear. This review aims to summarize the associations between these constructs, describe a neural mechanism mediating these relationships, and offer clinical strategies for the early identification and intervention of eating disorders. The gathered evidence shows that aggressiveness, impulsivity, and obsessive-compulsiveness may mediate or moderate the relationships between sex hormones and eating pathology, but only among females. Furthermore, sex hormone receptor density in the mesocorticolimbic dopamine pathway may explain the neural mechanism of these associations. Future research should use more comprehensive personality measurements and assess the mediation and moderation effects of temperament while taking the hormone levels of women across menstrual cycles into account. Additionally, electroencephalography and functional magnetic resonance imaging should be implemented to directly assess brain activity and corroborate these findings.

The reinforcement sensitivity theory affects questionnaire (RST-AQ). A validation study of a new scale targeting affects related to anxiety, approach motivation and fear

This paper presents the RST-AQ, a 22-item scale to measure the affective states related to the three motivational systems postulated by Reinforcement Sensitivity theory (RST-AQ): the Behavioral approach system (BAS), Behavioral inhibition system (BIS), and the Fight-Flight-Freeze system (FFFS). The three subscales are internally consistent. Results show an overall support for construct validity of our RST-AQ measure. The correlations of the RST-AQ subscales with other measures demonstrate a good convergent and divergent validity with regard to the subscales of BAS and BIS. The RTS-AQ Scale provides researcher with the first instrument to measures the affective states of the RST theory.