Psychobiology of the acute stress response and its relationship to the psychobiology of post-traumatic stress disorder

Self-reported Fatigue was Associated with Increased White-matter Alterations in Long-term Traumatic Brain Injury and Posttraumatic Stress Disorder Patients

Fatigue is a long-lasting problem in traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD), with limited research that investigated the fatigue-related white-matter changes within TBI and/or PTSD cohorts. This exploratory cross-sectional study used diffusion tensor imaging (DTI) and neuropsychological data collected from 153 male Vietnam War veterans, as part of the Alzheimer's Disease Neuroimaging Initiative - Department of Defense, and were divided clinically into control veterans, PTSD, TBI, and with both TBI and PTSD (TBI + PTSD). The existence of fatigue was defined by the question "Do you often feel tired, fatigued, or sleepy during the daytime?". DTI data were compared between fatigue and non-fatigue subgroups in each clinical group using tract-based spatial statistics voxel-based differences. Fatigue was reported in controls (29.55%), slightly higher in TBI (52.17%, PBenf = 0.06), and significantly higher in both TBI + PTSD (66.67%, PBenf = 0.001) and PTSD groups (79.25%, PBenf < 0.001). Compared to non-fatigued subgroups, no white-matter differences were observed in the fatigued subgroups of control or TBI, while the fatigued PTSD subgroup only showed increased diffusivity measures (i.e., radial and axial), and the fatigued TBI + PTSD subgroup showed decreased fractional anisotropy and increased diffusivity measures (PFWE ≤ 0.05). The results act as preliminary findings suggesting fatigue to be significantly reported in TBI + PTSD and PTSD decades post-trauma with a possible link to white-matter microstructural differences in both PTSD and TBI + PTSD. Future studies with larger cohorts and detailed fatigue assessments would be required to identify the white-matter changes associated with fatigue in these cohorts.

Stress-induced symptom exacerbation: Stress increases voiding frequency, somatic sensitivity, and urinary bladder NGF and BDNF expression in mice with subthreshold cyclophosphamide (CYP)

Symptom exacerbation due to stress is prevalent in many disease states, including functional disorders of the urinary bladder (e.g., overactive bladder (OAB), interstitial cystitis/bladder pain syndrome (IC/BPS)); however, the mechanisms underlying the effects of stress on micturition reflex function are unclear. In this study we designed and evaluated a stress-induced symptom exacerbation (SISE) mouse model that demonstrates increased urinary frequency and somatic (pelvic and hindpaw) sensitivity. Cyclophosphamide (CYP) (35 mg/kg; i.p., every 48 hours for a total of 4 doses) or 7 days of repeated variate stress (RVS) did not alter urinary bladder function or somatic sensitivity; however, both CYP alone and RVS alone significantly (p ≤ 0.01) decreased weight gain and increased serum corticosterone. CYP treatment when combined with RVS for 7 days (CYP+RVS) significantly (p ≤ 0.01) increased serum corticosterone, urinary frequency and somatic sensitivity and decreased weight gain. CYP+RVS exposure in mice significantly (p ≤ 0.01) increased (2.6-fold) voiding frequency as we determined using conscious, open-outlet cystometry. CYP+RVS significantly (p ≤ 0.05) increased baseline, threshold, and peak micturition pressures. We also evaluated the expression of NGF, BDNF, CXC chemokines and IL-6 in urinary bladder in CYP alone, RVS alone and CYP+RVS mouse cohorts. Although all treatments or exposures increased urinary bladder NGF, BDNF, CXC and IL-6 content, CYP+RVS produced the largest increase in all inflammatory mediators examined. These results demonstrated that CYP alone or RVS alone creates a change in the inflammatory environment of the urinary bladder but does not result in a change in bladder function or somatic sensitivity until CYP is combined with RVS (CYP+RVS). The SISE model of CYP+RVS will be useful to develop testable hypotheses addressing underlying mechanisms where psychological stress exacerbates symptoms in functional bladder disorders leading to identification of targets and potential treatments.

Sleep, circadian system and traumatic stress

The human circadian system creates and maintains cellular and systemic rhythmicity essential for the temporal organization of physiological processes promoting homeostasis and environmental adaptation. Sleep disruption and loss of circadian rhythmicity fundamentally affects master homeostasic regulating systems at the crossroads of peripheral and central susceptibility pathways, similar to acute or chronic stress and, thus, may play a central role in the development of stress-related disorders. Direct and indirect human and animal PTSD research accordingly suggests circadian-system-linked sleep, neuroendocrine, immune, metabolic and autonomic dysregulation, linking circadian misalignment to PTSD pathophysiology. Additionally, there is evidence that sleep and circadian disruption may represent a vital pre-existing risk factor in the prediction of PTSD development, while sleep-related symptoms are among the most prominent in trauma-associated disorders. These facts may represent a need for a shift towards a more chronobiological understanding of traumatic sequel and could support better prevention, evaluation and treatment of sleep and circadian disruption as first steps in PTSD management. In this special issue, we highlight and review recent advances from human sleep and chronobiological research that enhances our understanding of the development and maintenance of trauma-related disorders.

Traumatic stress and the circadian system: neurobiology, timing and treatment of posttraumatic chronodisruption

Background: Humans have an evolutionary need for a well-preserved internal 'clock', adjusted to the 24-hour rotation period of our planet. This intrinsic circadian timing system enables the temporal organization of numerous physiologic processes, from gene expression to behaviour. The human circadian system is tightly and bidirectionally interconnected to the human stress system, as both systems regulate each other's activity along the anticipated diurnal challenges. The understanding of the temporal relationship between stressors and stress responses is critical in the molecular pathophysiology of stress-and trauma-related diseases, such as posttraumatic stress disorder (PTSD). Objectives/Methods: In this narrative review, we present the functional components of the stress and circadian system and their multilevel interactions and discuss how traumatic stress can affect the harmonious interplay between the two systems. Results: Circadian dysregulation after trauma exposure (posttraumatic chronodisruption) may represent a core feature of trauma-related disorders mediating enduring neurobiological correlates of traumatic stress through a loss of the temporal order at different organizational levels. Posttraumatic chronodisruption may, thus, affect fundamental properties of neuroendocrine, immune and autonomic systems, leading to a breakdown of biobehavioral adaptive mechanisms with increased stress sensitivity and vulnerability. Given that many traumatic events occur in the late evening or night hours, we also describe how the time of day of trauma exposure can differentially affect the stress system and, finally, discuss potential chronotherapeutic interventions. Conclusion: Understanding the stress-related mechanisms susceptible to chronodisruption and their role in PTSD could deliver new insights into stress pathophysiology, provide better psychochronobiological treatment alternatives and enhance preventive strategies in stress-exposed populations.

Intrabladder PAC1 Receptor Antagonist, PACAP(6-38), Reduces Urinary Bladder Frequency and Pelvic Sensitivity in Mice Exposed to Repeated Variate Stress (RVS)

Stress causes symptom exacerbation in functional disorders of the urinary bladder. However, the potential mediators and underlying mechanisms of stress effects on micturition reflex function are unknown. We have characterized PACAP (Adcyap1) and PAC1 receptor (Adcyap1r1) signaling in stress-induced urinary bladder dysfunction in mice. We determined PACAP and PAC1 transcripts and protein expressions in the urinary bladder and lumbosacral dorsal root ganglia (DRG) and spinal cord in repeated variate stress (RVS) or control mouse (handling only) groups. RVS in mice significantly (p ≤ 0.01) increased serum corticosterone and urinary bladder NGF content and decreased weight gain. PACAP and PAC1 mRNA and protein were differentially regulated in lower urinary tract tissues with changes observed in lumbosacral DRG and spinal cord but not in urinary bladder. RVS exposure in mice significantly (p ≤ 0.01) increased (2.5-fold) voiding frequency as determined using conscious cystometry. Intrabladder administration of the PAC1 receptor antagonist, PACAP(6-38) (300 nM), significantly (p ≤ 0.01) increased infused volume (1.5-2.7-fold) to elicit a micturition event and increased the intercontraction interval (i.e., decreased voiding frequency) in mice exposed to RVS and in control mice, but changes were smaller in magnitude in control mice. We also evaluated the effect of PAC1 blockade at the level of the urinary bladder on pelvic sensitivity in RVS or control mouse groups using von Frey filament testing. Intrabladder administration of PACAP(6-38) (300 nM) significantly (p ≤ 0.01) reduced pelvic sensitivity following RVS. PACAP/receptor signaling in the CNS and PNS contributes to increased voiding frequency and pelvic sensitivity following RVS and may represent a potential target for therapeutic intervention.

Causal connection between dissociation and ongoing interpersonal violence: A systematic review

OBJECTIVE

To identify evidence for dissociation as a cause of ongoing interpersonal violence.

METHOD

A systematic review of the literature retrieved from ten databases.

RESULTS

Fifteen studies yielded from our search strategy have been included in the review; eleven of these were longitudinal and four were experimental. The evidence indicates that pathological dissociation may contribute towards enduring interpersonal violence. Thus, dissociation may account for instances of repeated victimisation. There are similar indications concerning offenders, but study designs in this area allow one to draw fewer causal conclusions. There is some evidence that dissociation decreases information processing from the limbic system, which may be one underlying neurofunctional mechanism of persistent violence.

CONCLUSION

There is growing evidence for dissociation as a cause of interpersonal violence. However, the available evidence is still limited, and our review rather reveals an important research gap. Future longitudinal and experimental studies aimed at clarifying the role of dissociation in the context of violence should take into account the theoretical and empirical complexity around the concept of dissociation.

A Systematic Review of Dissociation in Female Sex Workers

We analyze the empirical evidence for the association between the occurrence of dissociation and acting as a female sex worker (FSW). The ten screened databases included original research papers looking at the association between various abusive relationships and dissociation. From the initial 5942 records, we screened 554 full-text articles from which eleven studies met the inclusion criteria. Dissociation was mainly described as a strategy to cope with work related experiences, persisting from an early age in cases affected by childhood sexual abuse (CSA). Only one study investigated the occurrence of dissociative disorders. The other studies showed that the FSW population frequently exhibits dissociative symptoms. Most study participants were street FSW characterized by high rates of revictimization, a history of childhood sexual abuse, and of trauma-related and substance use disorders. Due to the selectivity of the study samples, conclusions cannot be generalized. Our findings disclose an important research gap. Further research on mental health among FSW should cover all fields of the sex industry in order to understand the roots of sex work (SW) and its sequelae. This could help develop and implement targeted interventions.

Multilevel Interactions of Stress and Circadian System: Implications for Traumatic Stress

The dramatic fluctuations in energy demands by the rhythmic succession of night and day on our planet has prompted a geophysical evolutionary need for biological temporal organization across phylogeny. The intrinsic circadian timing system (CS) represents a highly conserved and sophisticated internal "clock," adjusted to the 24-h rotation period of the earth, enabling a nyctohemeral coordination of numerous physiologic processes, from gene expression to behavior. The human CS is tightly and bidirectionally interconnected to the stress system (SS). Both systems are fundamental for survival and regulate each other's activity in order to prepare the organism for the anticipated cyclic challenges. Thereby, the understanding of the temporal relationship between stressors and stress responses is critical for the comprehension of the molecular basis of physiology and pathogenesis of disease. A critical loss of the harmonious timed order at different organizational levels may affect the fundamental properties of neuroendocrine, immune, and autonomic systems, leading to a breakdown of biobehavioral adaptative mechanisms with increased stress sensitivity and vulnerability. In this review, following an overview of the functional components of the SS and CS, we present their multilevel interactions and discuss how traumatic stress can alter the interplay between the two systems. Circadian dysregulation after traumatic stress exposure may represent a core feature of trauma-related disorders mediating enduring neurobiological correlates of trauma through maladaptive stress regulation. Understanding the mechanisms susceptible to circadian dysregulation and their role in stress-related disorders could provide new insights into disease mechanisms, advancing psychochronobiological treatment possibilities and preventive strategies in stress-exposed populations.

Posttraumatic stress disorder: a model of the longitudinal course and the role of risk factors

Posttraumatic stress disorder (PTSD) differs from other anxiety disorders in that experience of a traumatic event is necessary for the onset of the disorder. The condition runs a longitudinal course, involving a series of transitional states, with progressive modification occurring with time. Notably, only a small percentage of people that experience trauma will develop PTSD. Risk factors, such as prior trauma, prior psychiatric history, family psychiatric history, peritraumatic dissociation, acute stress symptoms, the nature of the biological response, and autonomic hyperarousal, need to be considered when setting up models to predict the course of the condition. These risk factors influence vulnerability to the onset of PTSD and its spontaneous remission. In the majority of cases, PTSD is accompanied by another condition, such as major depression, an anxiety disorder, or substance abuse. This comorbidity can also complicate the course of the disorder and raises questions about the role of PTSD in other psychiatric conditions. This article reviews what is known about the emergence of PTSD following exposure to a traumatic event using data from clinical studies.

Maternal posttraumatic stress disorder during the perinatal period and child outcomes: A systematic review

BACKGROUND

Approximately 3.3% of women in pregnancy have posttraumatic stress disorder (PTSD) and 4% of women postpartum PTSD. The impact of maternal PTSD during the perinatal period (from conception until one year postpartum) on child outcomes has not been systematically examined.

METHOD

A systematic review was conducted to synthesize and critically evaluate quantitative research investigating the association between perinatal PTSD and child outcomes. Databases EMBASE, BNI, Medline, PsycInfo and CINAHL were searched using specific inclusion and exclusion criteria.

RESULTS

26 papers reporting 21 studies were identified that examined associations between perinatal PTSD and postpartum birth outcomes, child development, and mother-infant relationship. Studies reviewed were heterogeneous, with poor-to-medium scores of methodological quality. Results showed that maternal postpartum PTSD is associated with low birth weight and lower rates of breastfeeding. Evidence for an association between maternal PTSD and preterm birth, fetal growth, head circumference, mother-infant interaction, the mother-infant relationship or child development is contradictory. Associations between maternal PTSD and infant salivary cortisol levels, and eating/sleeping difficulties are based on single studies, so require replication.

LIMITATIONS

Methodological weaknesses of the studies included insufficient sample size, use of invalidated measures, and limited external validity.

CONCLUSION

Findings suggest that perinatal PTSD is linked with some negative child outcomes. Early screening for PTSD during the perinatal period may be advisable and onward referral for effective treatment, if appropriate. Future research using larger sample sizes, validated and reliable clinical interviews to assess PTSD, and validated measures to assess a range of child outcomes, is needed.

PACAP/Receptor System in Urinary Bladder Dysfunction and Pelvic Pain Following Urinary Bladder Inflammation or Stress

Complex organization of CNS and PNS pathways is necessary for the coordinated and reciprocal functions of the urinary bladder, urethra and urethral sphincters. Injury, inflammation, psychogenic stress or diseases that affect these nerve pathways and target organs can produce lower urinary tract (LUT) dysfunction. Numerous neuropeptide/receptor systems are expressed in the neural pathways of the LUT and non-neural components of the LUT (e.g., urothelium) also express peptides. One such neuropeptide receptor system, pituitary adenylate cyclase-activating polypeptide (PACAP; Adcyap1) and its cognate receptor, PAC1 (Adcyap1r1), have tissue-specific distributions in the LUT. Mice with a genetic deletion of PACAP exhibit bladder dysfunction and altered somatic sensation. PACAP and associated receptors are expressed in the LUT and exhibit neuroplastic changes with neural injury, inflammation, and diseases of the LUT as well as psychogenic stress. Blockade of the PACAP/PAC1 receptor system reduces voiding frequency in preclinical animal models and transgenic mouse models that mirror some clinical symptoms of bladder dysfunction. A change in the balance of the expression and resulting function of the PACAP/receptor system in CNS and PNS bladder reflex pathways may underlie LUT dysfunction including symptoms of urinary urgency, increased voiding frequency, and visceral pain. The PACAP/receptor system in micturition pathways may represent a potential target for therapeutic intervention to reduce LUT dysfunction.

Effect of Inpatient Palliative Care During Hematopoietic Stem-Cell Transplant on Psychological Distress 6 Months After Transplant: Results of a Randomized Clinical Trial

Purpose Inpatient palliative care integrated with transplant care improves patients' quality of life (QOL) and symptom burden during hematopoietic stem-cell transplant (HCT). We assessed patients' mood, post-traumatic stress disorder (PTSD) symptoms, and QOL 6 months post-transplant. Methods We randomly assigned 160 patients with hematologic malignancies who underwent autologous or allogeneic HCT to inpatient palliative care integrated with transplant care (n = 81) or transplant care alone (n = 79). At baseline and 6 months post-transplant, we assessed mood, PTSD symptoms, and QOL with the Hospital Anxiety and Depression Scale and Patient Health Questionnaire, PTSD checklist, and Functional Assessment of Cancer Therapy-Bone Marrow Transplant. To assess symptom burden during HCT, we used the Edmonton Symptom Assessment Scale. We used analysis of covariance while controlling for baseline values to examine intervention effects and conducted causal mediation analyses to examine whether symptom burden or mood during HCT mediated the effect of the intervention on 6-month outcomes. Results We enrolled 160 (86%) of 186 potentially eligible patients between August 2014 and January 2016. At 6 months post-transplant, intervention participants reported lower depression symptoms on the Hospital Anxiety and Depression Scale and Patient Health Questionnaire (adjusted mean difference, -1.21 [95% CI, -2.26 to -0.16; P = .024] and -1.63 [95% CI, -3.08 to -0.19; P = .027], respectively) and lower PTSD symptoms (adjusted mean difference, -4.02; 95% CI, -7.18 to -0.86; P = .013), but no difference in QOL or anxiety. Symptom burden and anxiety during HCT hospitalization partially mediated the effect of the intervention on depression and PTSD at 6 months post-transplant. Conclusion Inpatient palliative care integrated with transplant care leads to improvements in depression and PTSD symptoms at 6 months post-transplant. Reduction in symptom burden and anxiety during HCT partially accounts for the effect of the intervention on these outcomes.

Post-Traumatic Stress Disorder: The Relationship Between the Fear Response and Chronic Stress

Post-traumatic stress disorder (PTSD) is a disabling psychiatric condition that can develop following a physical, psychological, or sexual trauma. Despite the growing body of literature examining the psychological and biological factors involved in PTSD psychopathology, specific biomarkers that may improve diagnosis and treatment of PTSD have yet to be identified and validated. This challenge may be attributed to the diverse array of symptoms that individuals with the disorder manifest. Examining the interrelated stress and fear systems allows for a more comprehensive study of these symptoms, and through this approach, which aligns with the research domain criteria (RDoC) framework, neural and psychophysiological measures of PTSD have emerged. In this review, we discuss PTSD neurobiology and treatment within the context of fear and stress network interactions and elucidate the advantages of using an RDoC approach to better understand PTSD with fear conditioning and extinction paradigms.

[Defusing of victims of the terrorist attacks in Paris. Elements of assessment one-month post-event]

The terrorist attacks (fusillades and suicide attacks) in Paris on 13 November 2015 have had a major psychic impact on all individuals directly or secondarily exposed to them. Medico-psychological unit (CUMP) of the Paris Île-de-France region's immediate care services were immediately mobilized and rapidly strengthened by all regional medico-psychological units (CUMP) throughout the country. Psychological assistance has been provided in several key points of Paris and specifically in the 11th district City Hall of Paris where Lyon's Medico-psychological unit was located. These specific immediate psychological assistances, referred to as a "defusing process" by the medico-psychological unit (CUMP), are mostly devoted to provide the victims with an entry point to a psychological healthcare relationship and give them a first sense of soothing and relief even though they do not prevent further psychological care follow up for the victims. Nonetheless, the potential therapeutic effect of this "defusing process" has not yet been sufficiently established nor demonstrated by any scientific study. A phoning survey was carried out one-month post-terrorist attacks and interviewed the 129 victims who benefited from the "defusing process" conducted by Lyon's medico-psychological unit (CUMP) in order to collect data and assess its effects. These people, whether directly exposed, bereaved relatives or witnesses, whose average age is 35, are mostly living in the Île-de-France region. Most of them present a high score on the IES-R scale, whether they were directly exposed, bereaved relatives or witnesses. Almost all of them (96.5%) experienced at least one medical care contact within this one-month post-trauma period with psychotropic medication for 37% of them. Regarding the defusing conducted by Lyon's medico-psychological unit (CUMP) in the 11th district City Hall of Paris, it appears that 93% of the victims who were looked after indicated that they were satisfied and 87.4% of them stated that they were soothed afterwards.

Potential pleiotropic beneficial effects of adjuvant melatonergic treatment in posttraumatic stress disorder

Loss of circadian rhythmicity fundamentally affects the neuroendocrine, immune, and autonomic system, similar to chronic stress and may play a central role in the development of stress-related disorders. Recent articles have focused on the role of sleep and circadian disruption in the pathophysiology of posttraumatic stress disorder (PTSD), suggesting that chronodisruption plays a causal role in PTSD development. Direct and indirect human and animal PTSD research suggests circadian system-linked neuroendocrine, immune, metabolic and autonomic dysregulation, linking circadian misalignment to PTSD pathophysiology. Recent experimental findings also support a specific role of the fundamental synchronizing pineal hormone melatonin in mechanisms of sleep, cognition and memory, metabolism, pain, neuroimmunomodulation, stress endocrinology and physiology, circadian gene expression, oxidative stress and epigenetics, all processes affected in PTSD. In the current paper, we review available literature underpinning a potentially beneficiary role of an add-on melatonergic treatment in PTSD pathophysiology and PTSD-related symptoms. The literature is presented as a narrative review, providing an overview on the most important and clinically relevant publications. We conclude that adjuvant melatonergic treatment could provide a potentially promising treatment strategy in the management of PTSD and especially PTSD-related syndromes and comorbidities. Rigorous preclinical and clinical studies are needed to validate this hypothesis.

Stress Response and Perinatal Reprogramming: Unraveling (Mal)adaptive Strategies

Environmental stressors induce coping strategies in the majority of individuals. The stress response, involving the activation of the hypothalamic-pituitary-adrenocortical axis and the consequent release of corticosteroid hormones, is indeed aimed at promoting metabolic, functional, and behavioral adaptations. However, behavioral stress is also associated with fast and long-lasting neurochemical, structural, and behavioral changes, leading to long-term remodeling of glutamate transmission, and increased susceptibility to neuropsychiatric disorders. Of note, early-life events, both in utero and during the early postnatal life, trigger reprogramming of the stress response, which is often associated with loss of stress resilience and ensuing neurobehavioral (mal)adaptations. Indeed, adverse experiences in early life are known to induce long-term stress-related neuropsychiatric disorders in vulnerable individuals. Here, we discuss recent findings about stress remodeling of excitatory neurotransmission and brain morphology in animal models of behavioral stress. These changes are likely driven by epigenetic factors that lie at the core of the stress-response reprogramming in individuals with a history of perinatal stress. We propose that reprogramming mechanisms may underlie the reorganization of excitatory neurotransmission in the short- and long-term response to stressful stimuli.

Cortisol response and psychological distress predict susceptibility to false memories for a trauma film

For eyewitness testimony to be considered reliable, it is important to ensure memory remains accurate following the event. As many testimonies involve traumatic, as opposed to neutral, events, it is important to consider the role of distress in susceptibility to false memories. The aim of this study was to investigate whether cortisol response following a stressor would be associated with susceptibility to false memories. Psychological distress responses were also investigated, specifically, dissociation, intrusions, and avoidance. Participants were allocated to one of three conditions: those who viewed a neutral film (N = 35), those who viewed a real trauma film (N = 35), and a trauma "reappraisal" group where participants were told the film was not real (N = 35). All received misinformation about the film in the form of a narrative. Participants provided saliva samples (to assess cortisol) and completed distress and memory questionnaires. Cortisol response was a significant predictor of the misinformation effect. Dissociation and avoidance were related to confabulations. In conclusion, following a stressor an individual may differ with regard to their psychological response to the event, and also whether they experience a cortisol increase. This may affect whether they are more distressed later on, and also whether they remember the event accurately.

Concepts of scientific integrative medicine applied to the physiology and pathophysiology of catecholamine systems

This review presents concepts of scientific integrative medicine and relates them to the physiology of catecholamine systems and to the pathophysiology of catecholamine-related disorders. The applications to catecholamine systems exemplify how scientific integrative medicine links systems biology with integrative physiology. Concepts of scientific integrative medicine include (i) negative feedback regulation, maintaining stability of the body's monitored variables; (ii) homeostats, which compare information about monitored variables with algorithms for responding; (iii) multiple effectors, enabling compensatory activation of alternative effectors and primitive specificity of stress response patterns; (iv) effector sharing, accounting for interactions among homeostats and phenomena such as hyperglycemia attending gastrointestinal bleeding and hyponatremia attending congestive heart failure; (v) stress, applying a definition as a state rather than as an environmental stimulus or stereotyped response; (vi) distress, using a noncircular definition that does not presume pathology; (vii) allostasis, corresponding to adaptive plasticity of feedback-regulated systems; and (viii) allostatic load, explaining chronic degenerative diseases in terms of effects of cumulative wear and tear. From computer models one can predict mathematically the effects of stress and allostatic load on the transition from wellness to symptomatic disease. The review describes acute and chronic clinical disorders involving catecholamine systems-especially Parkinson disease-and how these concepts relate to pathophysiology, early detection, and treatment and prevention strategies in the post-genome era.

Electrocortical processing of social signals of threat in combat-related post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is characterized by avoidance, emotional numbing, increased arousal and hypervigilance for threat following a trauma. Thirty-three veterans (19 with PTSD, 14 without PTSD) who had experienced combat trauma while on deployment in Iraq and/or Afghanistan completed an emotional faces matching task while electroencephalography was recorded. Vertex positive potentials (VPPs) elicited by happy, angry and fearful faces were smaller in veterans with versus without PTSD. In addition, veterans with PTSD exhibited smaller late positive potentials (LPPs) to angry faces and greater intrusive symptoms predicted smaller LPPs to fearful faces in the PTSD group. Veterans with PTSD were also less accurate at identifying angry faces, and accuracy decreased in the PTSD group as hyperarousal symptoms increased. These findings show reduced early processing of emotional faces, irrespective of valence, and blunted prolonged processing of social signals of threat in conjunction with impaired perception for angry faces in PTSD.

Modulation of physiological reflexes by pain: role of the locus coeruleus

The locus coeruleus (LC) is activated by noxious stimuli, and this activation leads to inhibition of perceived pain. As two physiological reflexes, the acoustic startle reflex and the pupillary light reflex, are sensitive to noxious stimuli, this review considers evidence that this sensitivity, at least to some extent, is mediated by the LC. The acoustic startle reflex, contraction of a large body of skeletal muscles in response to a sudden loud acoustic stimulus, can be enhanced by both directly ("sensitization") and indirectly ("fear conditioning") applied noxious stimuli. Fear-conditioning involves the association of a noxious (unconditioned) stimulus with a neutral (conditioned) stimulus (e.g., light), leading to the ability of the conditioned stimulus to evoke the "pain response". The enhancement of the startle response by conditioned fear ("fear-potentiated startle") involves the activation of the amygdala. The LC may also be involved in both sensitization and fear potentiation: pain signals activate the LC both directly and indirectly via the amygdala, which results in enhanced motoneurone activity, leading to an enhanced muscular response. Pupil diameter is under dual sympathetic/parasympathetic control, the sympathetic (noradrenergic) output dilating, and the parasympathetic (cholinergic) output constricting the pupil. The light reflex (constriction of the pupil in response to a light stimulus) operates via the parasympathetic output. The LC exerts a dual influence on pupillary control: it contributes to the sympathetic outflow and attenuates the parasympathetic output by inhibiting the Edinger-Westphal nucleus, the preganglionic cholinergic nucleus in the light reflex pathway. Noxious stimulation results in pupil dilation ("reflex dilation"), without any change in the light reflex response, consistent with sympathetic activation via the LC. Conditioned fear, on the other hand, results in the attenuation of the light reflex response ("fear-inhibited light reflex"), consistent with the inhibition of the parasympathetic light reflex via the LC. It is suggested that directly applied pain and fear-conditioning may affect different populations of autonomic neurones in the LC, directly applied pain activating sympathetic and fear-conditioning parasympathetic premotor neurones.

Psychosocial animal model of PTSD produces a long-lasting traumatic memory, an increase in general anxiety and PTSD-like glucocorticoid abnormalities

Post-traumatic stress disorder (PTSD) is characterized by a pathologically intense memory for a traumatic experience, persistent anxiety and physiological abnormalities, such as low baseline glucocorticoid levels and increased sensitivity to dexamethasone. We have addressed the hypothesis that rats subjected to chronic psychosocial stress would exhibit PTSD-like sequelae, including traumatic memory expression, increased anxiety and abnormal glucocorticoid responses. Adult male Sprague-Dawley rats were exposed to a cat on two occasions separated by 10 days, in conjunction with chronic social instability. Three weeks after the second cat exposure, the rats were tested for glucocorticoid abnormalities, general anxiety and their fear-conditioned memory of the two cat exposures. Stressed rats exhibited reduced basal glucocorticoid levels, increased glucocorticoid suppression following dexamethasone administration, heightened anxiety and a robust fear memory in response to cues that were paired with the two cat exposures. The commonalities in endocrine and behavioral measures between psychosocially stressed rats and traumatized people with PTSD provide the opportunity to explore mechanisms underlying psychological trauma-induced changes in neuroendocrine systems and cognition.

Are there implications for morphological changes in neck muscles after whiplash injury?

STUDY DESIGN

Literature review.

OBJECTIVE

To review the evidence related to the morphological changes (atrophy and fatty degeneration) of neck muscles in whiplash-associated disorders (WAD) and to highlight emerging evidence for the pathophysiological mechanisms behind muscle degeneration and their potential role in the transition from acute to chronic pain after whiplash injury from a motor vehicle crash (MVC).

SUMMARY OF BACKGROUND DATA

Magnetic resonance imaging (MRI) can be regarded as the gold standard for muscle imaging. There is emerging evidence to highlight in vivo features of neck muscle degeneration in patients with chronic WAD and the temporal development of such acute changes after MVC. However, the precise underlying mechanisms for such changes and their influence on functional recovery after whiplash remain largely unknown.

METHODS

Literature review of available evidence from both the authors' previous studies and other similar bodies of work.

RESULTS

Studies have quantified degenerative changes in the neck muscles of patients with acute and chronic whiplash with structural MRI applications.

CONCLUSION

Current evidence from structural MRI based studies demonstrates the widespread presence of fatty infiltrates in neck muscles of patients with chronic whiplash. Such findings have not shown to feature in patients with chronic insidious onset neck pain, suggesting traumatic factors play a role in their development. Recent studies have revealed that muscle fatty infiltrates manifest soon after whiplash but only in those with higher pain and disability and symptoms of post-traumatic stress disorder. The possibility that such muscle changes are associated with a more severe injury including poor functional recovery remains the focus of current research efforts.

The temporal development of fatty infiltrates in the neck muscles following whiplash injury: an association with pain and posttraumatic stress

BACKGROUND

Radiological findings associated with poor recovery following whiplash injury remain elusive. Muscle fatty infiltrates (MFI) in the cervical extensors on magnetic resonance imaging (MRI) in patients with chronic pain have been observed. Their association with specific aspects of pain and psychological factors have yet to be explored longitudinally.

MATERIALS AND FINDINGS

44 subjects with whiplash injury were enrolled at 4 weeks post-injury and classified at 6 months using scores on the Neck Disability Index as recovered, mild and moderate/severe. A measure for MFI and patient self-report of pain, loss of cervical range of movement and posttraumatic stress disorder (PTSD) were collected at 4 weeks, 3 months and 6 months post-injury. The effects of time and group and the interaction of time by group on MFI were determined. We assessed the mediating effect of posttraumatic stress and cervical range of movement on the longitudinal relationship between initial pain intensity and MFI. There was no difference in MFI across all groups at enrollment. MFI values increased in the moderate/severe group and were significantly higher in comparison to the recovered and mild groups at 3 and 6 months. No differences in MFI values were found between the mild and recovered groups. Initial severity of PTSD symptoms mediated the relationship between pain intensity and MFI at 6 months. Initial ROM loss did not.

CONCLUSIONS

MFI in the cervical extensors occur soon following whiplash injury and suggest the possibility for the occurrence of a more severe injury with subsequent PTSD in patients with persistent symptoms.

Support for religio-political aggression among teenaged boys in Gaza: part II: neuroendocrinological findings

Hormones seem to play important roles in the regulation of human aggression. Multiple studies have confirmed that testosterone (T) levels exhibit complex relationships with aggression, dominance, and/or risk-taking behavior. Some evidence suggests that cortisol (CORT) interacts with T and may also be associated with aspects of mood and aggression. However, almost no research to date has investigated the possibility that these neuroendocrine factors are associated with variations in political attitudes or with political aggression. During the second intifada, we tested the hypothesis that morning salivary T and/or salivary CORT levels might be associated with self-rated aggression or with support for religio-political aggression (RPA) among 14-year-old Palestinian boys living in Gaza. We obtained and averaged weekly 09:00 hr salivary measures of T and CORT for more than 1 month. Averaged morning T levels did not correlate with self-rated aggression, but were positively associated with agreement with the statement "religious ends justify any means," (r = .355, P = .014) and marginally associated with a composite measure of support for RPA (r = .247, P = .094). Average CORT levels were inversely correlated with self-rated aggression (r = -.328, P = .037) and with anger (r = -.373, P = .016), but CORT levels were not associated with support for RPA or with the statement "religious ends justify any means." Acknowledging that a modest sample size and methodological issues necessarily limit confidence in our conclusions, these results may represent the first findings regarding neurobiological correlates of support for political aggression.

Development of lifetime comorbidity in the World Health Organization world mental health surveys

CONTEXT

Although numerous studies have examined the role of latent variables in the structure of comorbidity among mental disorders, none has examined their role in the development of comorbidity.

OBJECTIVE

To study the role of latent variables in the development of comorbidity among 18 lifetime DSM-IV disorders in the World Health Organization World Mental Health Surveys.

DESIGN

Nationally or regionally representative community surveys.

SETTING

Fourteen countries.

PARTICIPANTS

A total of 21 229 survey respondents.

MAIN OUTCOME MEASURES

First onset of 18 lifetime DSM-IV anxiety, mood, behavior, and substance disorders assessed retrospectively in the World Health Organization Composite International Diagnostic Interview.

RESULTS

Separate internalizing (anxiety and mood disorders) and externalizing (behavior and substance disorders) factors were found in exploratory factor analysis of lifetime disorders. Consistently significant positive time-lagged associations were found in survival analyses for virtually all temporally primary lifetime disorders predicting subsequent onset of other disorders. Within-domain (ie, internalizing or externalizing) associations were generally stronger than between-domain associations. Most time-lagged associations were explained by a model that assumed the existence of mediating latent internalizing and externalizing variables. Specific phobia and obsessive-compulsive disorder (internalizing) and hyperactivity and oppositional defiant disorders (externalizing) were the most important predictors. A small number of residual associations remained significant after controlling the latent variables.

CONCLUSIONS

The good fit of the latent variable model suggests that common causal pathways account for most of the comorbidity among the disorders considered herein. These common pathways should be the focus of future research on the development of comorbidity, although several important pairwise associations that cannot be accounted for by latent variables also exist that warrant further focused study.

Synaptic plasticity in the pathophysiology and treatment of bipolar disorder

Emerging evidence suggests that synaptic plasticity is intimately involved in the pathophysiology and treatment of bipolar disorder (BPD). Under certain conditions, over-strengthened and/or weakened synapses at different circuits in the brain could disturb brain functions in parallel, causing manic-like or depressive-like behaviors in animal models. In this chapter, we summarize the regulation of synaptic plasticity by medications, psychological conditions, hormones, and neurotrophic factors, and their correlation with mood-associated animal behaviors. We conclude that increased serotonin, norepinephrine, dopamine, brain-derived neurotrophic factor (BDNF), acute corticosterone, and antidepressant treatments lead to enhanced synaptic strength in the hippocampus and also correlate with antidepressant-like behaviors. In contrast, inhibiting monoaminergic signaling, long-term stress, and pathophysiological concentrations of cytokines weakens glutamatergic synaptic strength in the hippocampus and is associated with depressive-like symptoms.

The long-term costs of traumatic stress: intertwined physical and psychological consequences

The gradual emergence of symptoms following exposure to traumatic events has presented a major conceptual challenge to psychiatry. The mechanism that causes the progressive escalation of symptoms with the passage of time leading to delayed onset post-traumatic stress disorder (PTSD) involves the process of sensitization and kindling. The development of traumatic memories at the time of stress exposure represents a major vulnerability through repeated environmental triggering of the increasing dysregulation of an individual's neurobiology. An increasing body of evidence demonstrates how the increased allostatic load associated with PTSD is associated with a significant body of physical morbidity in the form of chronic musculoskeletal pain, hypertension, hyperlipidaemia, obesity and cardiovascular disease. This increasing body of literature suggests that the effects of traumatic stress need to be considered as a major environmental challenge that places individual's physical and psychological health equally at risk. This broader perspective has important implications for developing treatments that address the underlying dysregulation of cortical arousal and neurohormonal abnormalities following exposure to traumatic stress.

A genome-wide panel of congenic mice reveals widespread epistasis of behavior quantitative trait loci

Understanding the genetics of behavioral variation remains a fascinating but difficult problem with considerable theoretical and practical implications. We used the genome-tagged mice (GTM) and an extensive test battery of well-validated behavioral assays to scan the genome for behavioral quantitative trait loci (QTLs). The GTM are a panel of 'speed congenic' mice consisting of over 60 strains spanning the entire autosomal genome. Each strain harbors a small (approximately 23 cM) DBA/2J donor segment on a uniform C57BL/6J background. The panel allows for mapping to regions as small as 5 cM and provides a powerful new tool for increasing mapping power and replicability in the analysis of QTLs. A total of 97 loci were mapped for a variety of complex behavioral traits including hyperactivity, anxiety, prepulse inhibition, avoidance and conditional fear. A larger number of loci were recovered than generally attained from standard mapping crosses. In addition, a surprisingly high proportion of loci, 63%, showed phenotypes unlike either of the parental strains. These data suggest that epistasis decreases sensitivity of locus detection in traditional crosses and demonstrate the utility of the GTM for mapping complex behavioral traits with high sensitivity and precision.

Endogenous cortisol suppression with metyrapone enhances acoustic startle in healthy subjects

Previous human studies have shown that excess cortisol sufficient to fully occupy central nervous system (CNS) corticosteroid receptors may reduce startle eye blink. The present study tested whether cortisol depletion and the resulting reduction in activity of CNS corticosteroid receptors has the opposite effect. In a single-blind, placebo-controlled, randomized study, eye blink EMG responses to 105 dB acoustic startle stimuli were assessed in 25 healthy subjects who received oral metyrapone (1500 mg) to suppress endogenous cortisol production, while 24 controls received oral placebo. As expected, metyrapone significantly reduced salivary cortisol, indicating effective endogenous cortisol suppression. Startle eye blink responses were significantly increased in the metyrapone group. Short-term habituation of the startle reflex was not different between groups. Our results suggest that startle is enhanced during depletion of cortisol. This effect may be mediated by CNS mechanisms controlling cortisol feedback.

Proinflammatory markers in prediction of posttraumatic psychological symptoms: a prospective cohort study

Introduction. Posttraumatic psychopathology (PTP) describes the spectrum of conditions that can complicate the recovery from commonly occurring musculoskeletal trauma. There is a clear association with the activation of the hypothalamic-pituitary-adrenal axis (HPAA), and we wished to examine the predictive value of proinflammatory markers of the HPAA and of the GABA, which acts as an inhibitory regulator. Methods. Levels of proinflammatory markers and GABA were measured in 84 patients who had suffered musculoskeletal injuries requiring hospitalisation. PTP was assessed by the use of the General Health Questionnaire (GHQ) at presentation and again at two- and six-month reviews. Results. Significant psychological disturbance was noted in 39% of patients at two months and falling back to 18% by six months. There was no correlation between any of the markers tested at presentation and PTP at follow-up. Discussion. The HPAA response to trauma and the development of PTP are extremely complex. It is unlikely that a simple blood assay will provide significant predictive information, while incident specific information and patient perception are of more practical use.

The impact of unintentional pediatric trauma: a review of pain, acute stress, and posttraumatic stress

This article reviews current research on acute stress disorder (ASD) and posttraumatic stress disorder (PTSD) resulting from pediatric simple (i.e., single, unpredictable, and unintentional) physical injury and how pain may act as both a trigger and a coexisting symptom. Although several studies have explored predictors of ASD and PTSD, as well as the relationship between these conditions in adults, there is less research on ASD and PTSD in children and adolescents. This review highlights the importance of early detection of pain and acute stress symptoms resulting from pediatric unintentional physical injury in the hopes of preventing long-term negative outcomes, such as the potential development of PTSD and associated academic, social, and psychological problems.

Longitudinal determinants of posttraumatic stress in a population-based cohort study

BACKGROUND

Posttraumatic stress disorder is a prevalent and disabling psychologic pathology. Longitudinal research on the predictors of posttraumatic stress symptomatology is limited.

METHODS

We recruited 2752 participants to a prospective, population-based cohort study by conducting a telephone survey of adult residents of the New York City metropolitan area in 2002; participants completed 3 follow-up interviews over a 30-month period. Censoring weights were estimated to account for potential bias. We used generalized estimating equation logistic regression models with bootstrapped confidence intervals to assess the predictors of posttraumatic stress over time in multivariable models.

RESULTS

Predictors of posttraumatic stress over time included ongoing stressors (odds ratio [OR] = 1.91 per 1 unit increase in number of stressors, [95% confidence interval = 1.55-2.36]) and traumatic events (OR = 1.92 per 1 unit increase in number of traumatic events [CI = 1.71-2.22]), social support (compared with high levels, OR = 1.71 for medium [1.09-2.52]; OR = 1.57 for low [1.08-2.35]), low income (OR = 0.87 per $10,000 increase [0.81-0.92]), female sex (1.60 [1.11-2.23]), and Latino ethnicity (compared with white, OR = 1.74 [1.05-2.97]).

CONCLUSIONS

These findings suggest that ongoing stressors play a central role in explaining the trajectory of posttraumatic stress over time, and that factors beyond the experience of stressors and traumas may account for sex and ethnic differences in posttraumatic stress risk. Interventions that focus on reducing ongoing adversity may help mitigate the consequences of traumatic events.

Neurobiological alterations associated with traumatic stress

PURPOSE

The purpose of this article is to describe the effects of traumatic stress on brain structure and function, and the relationship of these neurobiological changes to symptoms experienced after trauma.

CONCLUSIONS

Exposure to traumatic stress is associated with changes in the limbic system, the hypothalamic-pituitary-adrenal axis, and key monoamine neurotransmitters. Different neurobiological alterations can be linked to specific symptoms of hyperarousal, dissociation/numbing, and reexperiencing of the trauma.

PRACTICE IMPLICATIONS

Understanding what is happening in the brain can inform more targeted treatment for various symptoms that the individual may be experiencing.

Stress-related musculoskeletal pain

While stress is often considered by patients and clinicians alike as an important factor in the onset and maintenance of widespread musculoskeletal pain, the relationship is more complex than appears on initial consideration. The types of event that lead to stress need description, and the role of traumatic events are particularly important because of the shared association with post-traumatic stress disorder. The substantial overlap with psychiatric disorders and the role of stress in their aetiology must be assessed in patients. The lack of specificity of the symptoms of the different disorders used to describe widespread musculoskeletal pain may be explained by their shared aetiology, including neural sensitization and alterations of the hypothalamic-pituitary-adrenal (HPA) axis due to stress. Fear avoidance is a central stress-related perceptual characteristic and behavioural dimension in these disorders. Treatment depends on thorough assessment, including psychiatric diagnosis, avoiding simplistic attributions and implementing evidence-based treatments that are well documented.

Psychological distress and coping in breast cancer patients and healthy women whose parents survived the Holocaust

Psychological distress levels of breast cancer patients whose parents were Holocaust survivors ('second-generation Holocaust' patients) were previously shown to be significantly higher than those of a matched group of patients with non-traumatized parents. In this study, we investigated whether this effect reflects only the generally higher distress levels of second-generation Holocaust women or whether breast cancer patients with traumatized parents also present lower adaptation abilities, which result in increased distress to the breast cancer diagnosis. We assessed psychological distress and measures of coping in 193 second-generation Holocaust patients diagnosed with breast cancer, 164 breast cancer patients with non-traumatized parents, 176 healthy second-generation Holocaust women, and 143 healthy women with non-traumatized parents. The main effect of cancer and the main effect of second-generation Holocaust survivor on psychological distress were found to be significant. These two factors (cancer x second generation) had a synergistic effect on the levels of depression and psychoticism. These results support the hypothesis that, at least on some psychological measures, the cumulative distressing effect of having traumatized parents and breast cancer diagnosis is higher than the effect of each factor alone.

Establishing an agenda for translational research on PTSD

Animal research on brain mechanisms involved in psychiatric disorders presents an enormous challenge because it is impossible to precisely model symptoms of a human disorder in a rat or mouse. Nevertheless, there are uses for animal models as long as the limitations are recognized. Animal research related to posttraumatic stress disorder (PTSD) points to acute and chronic stressors, such as restraint or immobilization as being the most relevant stimuli to study how neural and endocrine systems are affected, both immediately and long term. Of particular relevance are the onset and duration of effects of stressors on brain areas subserving emotional memories, such as the amygdala, prefrontal cortex, and hippocampus. The hippocampus plays a role in memory and in vegetative functions of the body. The hippocampus receives input from the amygdala and its function in spatial memory is altered by amygdala activity. Repeated stress in the rat suppresses dentate gyrus neurogenesis and causes dendrites of hippocampal and medial prefrontal cortical neurons to shrink. Conversely, it causes basolateral amygdala neurons to increase in dendritic complexity and sprout new synapses. Repeated stress also increases fear and aggression, reduces spatial memory, and alters contextual fear conditioning. Antidepressants and mood stabilizers have diverse effects on these processes. New data indicate that a single stress episode can cause a delayed alteration in synapse formation in the basolateral amygdala without changing dendritic length and branching. Further studies are examining the structural changes in prefrontal cortex and hippocampus as a result of single traumatic stressors, which may reflect the functional interactions with the amygdala. Together with mechanistic studies of the role of adrenal glucocorticoids and catecholamines, these results may tell us how the brain is shaped by acute and repeated uncontrollable stress in ways that then can be investigated in human anxiety disorders.

Effects of age-related hearing loss on startle reflex and prepulse inhibition in mice on pure and mixed C57BL and 129 genetic background

The present study examined the developmental course of the age-related hearing loss and its consequences on the expression of acoustic startle reflex (ASR) and prepulse inhibition (PPI) generated by white-noise bursts in 129S2/SvPas (129) and C57BL/6J (C57) mouse strains and their F(1) hybrids. Auditory brainstem responses (ABR), ASR and PPI were assessed at various time points: 6, 28, 41 and 94 weeks. Both parental strains showed marked ABR threshold shifts with age, with C57 mice having the most pronounced deficits. By contrast, the hybrids displayed only minor hearing loss with age. The time courses of ASR and PPI varied considerably between the mouse strains. From 6 to 41 weeks of age, ASR and PPI elicited by weak stimuli (70-90dB) increased in C57 mice, whereas the startle responses to intense stimuli (95-120dB) declined progressively. In 129 and hybrid mice, PPI levels remained relatively stable during the first year, but a progressive increase of ASR was observed in the hybrids for intense stimuli (95-120dB). When animals reached 94 weeks of age, marked deterioration of ASR was observed in all strains, while deficits in PPI were only seen in 129 and C57 mice. These findings show that the time course and the severity of the hearing loss vary considerably between 129, C57 strains and their hybrids, thus suggesting a marked heterogeneity in the genetic mechanisms underlying deafness in mice. They also demonstrate that the age-related hearing loss may have complex consequences on auditory behavioral performances depending of the severity of the deficits, the genetic background as well as the stimuli parameters.

Anxiogenic-like effect of chronic corticosterone in the light-dark emergence task in mice

Chronic hypercortisolemia is a hallmark of neuroendocrine and psychiatric disorders, such as Cushing's disease and depression. Whether cortisol directly contributes to the altered mood and anxiety symptoms seen in these diseases remains unclear. To address this, the authors have modeled hypercortisolemia by administering corticosterone in the drinking water of female Swiss Webster mice for 17 or 18 days (13 mg/kg). Light-dark emergence, startle habituation, and startle reactivity were measured. Chronic but not acute treatment with corticosterone increased the latency to emerge into the light compartment, an anxiogenic-like effect. Chronic corticosterone treatment did not affect startle habituation, but did reduce startle reactivity. This study suggests that chronic hypercortisolemia may contribute to anxiety-related behavior in patients with Cushing's disease and depression.

Increased fear response to contextual cues in mice lacking the 5-HT1A receptor

Serotonin 1A receptor knockout (5-HT1AR KO) mice exhibit increased behavioral inhibition in conflict tests. To gain further insight into their anxiety-related phenotype, we subjected these mice to additional behavioral tests. First, we considered whether behavioral inhibition in these knockout mice is a consequence of reduced exploratory motivation. The knockout mice engage in normal exploration during a light-dark test and normal exploration of a novel object in a familiar environment, suggesting that the anxiety-related phenotype is not due to reduced exploratory drive. Second, we tested whether these mice exhibit increased behavioral inhibition in response to any aversive cues, or whether this response depends on cue modality. Knockout mice respond normally to discrete aversive cues in the Vogel lick-suppression test, arguing that their phenotype is restricted to conflict tests based on complex or spatial aversive cues. Third, to probe the processing of spatial aversive cues, we assessed fear conditioning to contextual cues. After contextual fear conditioning, knockout and wild-type (WT) mice express freezing responses when exposed to the training environment. However, when placed in an ambiguous environment containing both conditioned and novel cues, the freezing response of knockout mice does not significantly decrease as it does in WT mice, suggesting that the knockout fear response is biased toward threatening cues. We hypothesize that this inappropriate generalization of fearful behavior to a context containing both fearful and neutral stimuli, a phenomenon that occurs in a subset of human anxiety disorders such as panic disorder and post-traumatic stress disorder, underlies the anxiety phenotype of 5-HT1AR KO mice.

The bed nucleus of the stria terminalis in the Syrian hamster: subnuclei and connections of the posterior division

The bed nucleus of the stria terminalis is a key part of a ring of cells extending between the centromedial amygdala and bed nucleus of the stria terminalis referred to as the extended amygdala. The present study describes the architecture of the bed nucleus of the stria terminalis and the connections of subnuclei in posterior bed nucleus of the stria terminalis. The hamster bed nucleus of the stria terminalis is readily allotted to anterior and posterior divisions separated by the fibers of the body of the anterior commissure. The anterior division has four subnuclei: anteromedial, anterointermediate, anterolateral, and anteroventral. Within the posterior division, there are three distinct regions: posteromedial, posterointermediate, and posterolateral. In hamsters, the posterior bed nucleus of the stria terminalis contributes to male sexual behavior, particularly chemoinvestigation. Moreover, the posterior bed nucleus of the stria terminalis is part of a neural circuit essential for mating, including the medial amygdaloid nucleus and medial preoptic area. The connections of bed nucleus of the stria terminalis, posteromedial part, bed nucleus of the stria terminalis, posterointermediate part and bed nucleus of the stria terminalis, posterolateral part were visualized by co-injection of anterograde (Phaseolus vulgaris leucoagglutinin) and retrograde (cholera toxin B) tract tracers. The bed nucleus of the stria terminalis, posterointermediate part and bed nucleus of the stria terminalis, posteromedial part have dense bidirectional connections with medial amygdaloid nucleus and cortical amygdala via the stria terminalis and ventral amygdalofugal pathway. These subnuclei also maintain bidirectional connections with steroid-concentrating areas including lateral septum, medial preoptic area, hypothalamus, and periaqueductal gray. The bed nucleus of the stria terminalis, posterointermediate part and bed nucleus of the stria terminalis, posteromedial part receive projections from the subiculum and send projections to deep mesencephalic nuclei. By contrast, the bed nucleus of the stria terminalis, posterolateral part is connected with the central amygdala, lateral hypothalamus, subthalamic nucleus, nucleus accumbens, substantia innominata, substantia nigra and thalamus. Thus, the bed nucleus of the stria terminalis, posterointermediate part and bed nucleus of the stria terminalis, posteromedial part have similar connections with areas involved in social behaviors. The bed nucleus of the stria terminalis, posterolateral part maintains connections with areas involved in motivational circuits. This supports the concept of distinct circuits within the extended amygdala which differentially link the centromedial amygdala and bed nucleus of the stria terminalis.

The psychobiology of children exposed to marital violence

We examined the psychological and physiological functioning of a community sample of children exposed to marital violence, comparing them to a clinical comparison group without marital violence exposure. Results replicated past findings of elevated levels of trauma symptomatology in this population. Further, children exposed to marital violence differed significantly from comparison children with respect to sympathetic nervous system functioning and hypothalamic-pituitary-adrenal (HPA) axis functioning. Specifically, elevations were seen in heart rate and salivary cortisol levels, but not in orthostatic challenge response or blood pressure. These results indicate that children exposed to marital violence have a different physiological presentation than controls and may be physiologically "traumatized" by virtue of marital violence exposure.

Absence of behavioral sensitization in healthy human subjects following repeated exposure to ketamine

RATIONALE

Sensitization to the effects of N-methyl-D-aspartate (NMDA) glutamate receptor antagonists is robust in animals. However, the applicability of this model to humans is unclear because it currently rests on highly confounded retrospective studies of individuals who experienced protracted psychoses following repeated binges with NMDA receptor antagonists.

OBJECTIVES

The purpose of the current study was to determine whether there was evidence of sensitization to the behavioral effects of ketamine in healthy human subjects with repeated exposure to this drug.

METHODS

Data were studied from 295 healthy human subjects who participated in one or more of 11 separate studies that involved ketamine administration over 14 years. Positive and negative symptoms (Brief Psychiatric Rating Scale: BPRS), perceptual alterations (Clinician-Administered Dissociative States Scale: CADSS), and "high" and "anxiety" states (Visual Analog Scale: VAS) that were measured in all studies were included as outcome measures.

RESULTS

After including the number of previous exposures, number of previous studies, and time since first exposure as variables, repeated exposure to ketamine did not result in increased behavioral responses, suggestive of behavioral sensitization.

CONCLUSIONS

The current data do not provide evidence that repeated exposure to ketamine, albeit limited, is associated with sensitization to the behavioral effects of ketamine.

Distribution of the NMDA receptor NR3A subunit in the adult pig-tail macaque brain

The NMDA subtype of glutamate receptors are heteromeric complexes comprised of multiple subunits encoded by at least seven different genes (NR1, NR2A-2D and NR3A-3B), and differential expression of these subunits alters the pharmacological and electrophysiological properties of NMDA receptors. NR3A is a recently identified unique modulatory subunit that decreases NMDA receptor current and calcium influx. In rodents, NR3A is developmentally expressed, displaying robust expression early in development that declines with age, reaching low levels in the adult brain. A distinct and highly selective pattern of expression is observed in the developing and mature rodent brain, suggesting that NR3A may play a very specific role in NMDA receptor-mediated processes. NR3A expression in other species, however, is unknown. Therefore, we examined the expression of NR3A mRNA and protein in the adult macaque brain. Our results indicate that NR3A mRNA is expressed throughout much of the adult primate brain, and at high levels in specific brain regions including the neocortex, substantia nigra par compacta and cerebellum, as well as select areas of the hippocampus, amygdala, thalamus and hypothalamus. Western blot analysis reflects that this protein is translated and expressed in multiple brain regions. In contrast to the rat mRNA, our results suggest that NR3A transcript is widely expressed in the adult primate brain. Particular enrichment in some brain areas may reflect brain-region or circuit-specific functions for this NMDA receptor subunit.

Disturbance of pro-inflammatory cytokines in post-traumatic psychopathology

BACKGROUND

Post-traumatic psychopathology (PTP) is important to the orthopaedic surgeon as it may complicate the recovery from musculoskeletal injury. PTP is associated with a disturbance of the hypothalamic-pituitary-adrenal axis, and may lead to impaired healing. We have investigated the relationship between PTP and pro-inflammatory markers of the metabolic response to trauma.

MATERIALS AND METHODS

A prospective cohort study of 82 patients with musculoskeletal injuries, correlating development of psychopathology (measured by general health questionnaire) and pro-inflammatory markers (CRP, IL-6, sIL-6r, TNF-alpha) two and six months after their injury.

RESULTS

Psychological disturbance was found in 39% of patients at two months and 18% at six months. This disturbance was associated with significantly increased levels of IL-6 at two months and of sIL-6r and TNF-alpha at six months. CRP levels were not related to the development of PTP.

CONCLUSIONS

The relationship between PTP and disturbances of pro-inflammatory markers needs further exploration, but may explain in part the impaired functional recovery when musculoskeletal trauma is complicated by psychological disturbance.

Adaptations or pathologies? Long-term changes in brain and behavior after a single exposure to severe threat

The experience of a single threatening situation may alter the behavior of an animal in a long-lasting way. Long-lasting changes in behavior have been induced in laboratory animals to model and investigate the development and neural substrate of human psychopathologies. Under natural conditions, however, changes in behavior after an aversive experience may be adaptive because behavioral modifications allow animals to adjust to a threat for extended periods of time. In the laboratory setting, properties of the aversive situation and the potential of the animal to respond to the threat may be altered and lead to extensive, prolonged changes, indicating a failure in behavioral regulation. Such long-term changes seem to be mediated by neuronal alterations in components of the fear pathway. To understand psychopathologies, determinants of exaggerated responsivity and the underlying molecular and neural processes have to be analyzed in a comparative way under conditions that produce normal and abnormal fear and anxiety.

A review of the modulation of the startle reflex by affective states and its application in psychiatry

OBJECTIVE

To provide an overview of startle reflex methodologies applied to the examination of emotional and motivational states in humans and to review the findings in different forms of psychopathology.

METHODS

Pertinent articles were searched mostly via MEDLINE and PsycINFO.

RESULTS

The startle reflex is a non-invasive translational tool of research that bridges the gap between animal and human investigations. Startle is used to study fear and anxiety, affective disturbances, sensitization, motivational states, and homeostasis.

CONCLUSIONS

The startle reflex is highly sensitive to various factors that are of interest in the studies of emotional disorders and has promoted new areas of investigations in psychiatry. However, research in psychiatry is still in its infancy and most findings await replication. Future progress will benefit from the development of innovative and powerful designs tailored to investigate specific disorders.

SIGNIFICANCE

The startle reflex has utility as a research tool to examine trauma-related disorders, fear learning, drug addiction, and to contrast affective states and emotional processing across diagnostic groups, but its usefulness as a diagnostic tool is limited.

Increased beclomethasone-induced vasoconstriction in women with posttraumatic stress disorder

It has been hypothesized that patients with posttraumatic stress disorder (PTSD) show increased glucocorticoid sensitivity. The study tested beclomethasone-induced vasoconstriction (BIV), a measure of peripheral glucocorticoid sensitivity, in women with PTSD. A case-control design was employed in 33 PTSD patients and 33 healthy controls. BIV was tested using beclomethasone dipropionate (1-100 micro g/ml). Vasoconstriction was assessed after 15-18 h. Waking and afternoon salivary cortisol concentrations were measured. BIV ratings were significantly increased in PTSD at beclomethasone concentrations from 10-100 micro g/ml. Salivary cortisol concentrations did not differ between groups or correlate with BIV. Preliminary evidence has been found for increased peripheral glucocorticoid sensitivity in PTSD. Further study is required to replicate this finding and assess its relationship to the pathophysiology of the disorder.