Strategies to improve the quality and usefulness of mental health trials in humanitarian settings

A striking rise in the number of people affected by humanitarian crises has led to an increase in mental health and psychosocial support interventions to reduce the psychological effects of such crises. In a parallel trend, researchers have brought increased methodological rigour to their evaluation of these interventions. However, several methodological issues still constrain the quality and real-world relevance of the existing evidence base. We examine five core challenges in randomised controlled trials of mental health and psychosocial support interventions with conflict-affected and disaster-affected populations. These challenges are: translating intervention effects into metrics of real-world significance; giving adequate consideration to the selection and monitoring of control conditions; following rigorous processes to ensure outcome measures are culturally appropriate and psychometrically sound; ensuring and monitoring implementation variables, including fidelity, exposure, participant engagement, and the competence of implementation staff; and assessing mechanisms of change.

Afghan mental health and psychosocial well-being: thematic review of four decades of research and interventions

BACKGROUND

Four decades of war, political upheaval, economic deprivation and forced displacement have profoundly affected both in-country and refugee Afghan populations.

AIMS

We reviewed literature on mental health and psychosocial well-being, to assess the current evidence and describe mental healthcare systems, including government programmes and community-based interventions.

METHOD

In 2022, we conducted a systematic search in Google Scholar, PTSDpubs, PubMed and PsycINFO, and a hand search of grey literature (N = 214 papers). We identified the main factors driving the epidemiology of mental health problems, culturally salient understandings of psychological distress, coping strategies and help-seeking behaviours, and interventions for mental health and psychosocial support.

RESULTS

Mental health problems and psychological distress show higher risks for women, ethnic minorities, people with disabilities and youth. Issues of suicidality and drug use are emerging problems that are understudied. Afghans use specific vocabulary to convey psychological distress, drawing on culturally relevant concepts of body-mind relationships. Coping strategies are largely embedded in one's faith and family. Over the past two decades, concerted efforts were made to integrate mental health into the nation's healthcare system, train cadres of psychosocial counsellors, and develop community-based psychosocial initiatives with the help of non-governmental organisations. A small but growing body of research is emerging around psychological interventions adapted to Afghan contexts and culture.

CONCLUSIONS

We make four recommendations to promote health equity and sustainable systems of care. Interventions must build cultural relevance, invest in community-based psychosocial support and evidence-based psychological interventions, maintain core mental health services at logical points of access and foster integrated systems of care.

Effectiveness of the caregiver support intervention on child psychosocial wellbeing among Syrian refugees in Lebanon: Mediation and secondary analysis of a Randomized Controlled Trial

BACKGROUND

War and violence have a serious negative impact on the wellbeing and mental health of many children. Caregivers play an important role in mitigating or exacerbating this impact.

OBJECTIVE

This study evaluates the impact of the nine session Caregiver Support Intervention on improving children's wellbeing and examines putative mediators of changes in children's psychosocial wellbeing.

PARTICIPANTS AND SETTING

240 female caregivers were randomly allocated (1:1) to the CSI or a waitlist control comparison condition. The study was implemented in Lebanon, in an area characterized by high levels of poverty and a high number of the Syrian refugees.

METHODS

A parallel group Randomized Controlled Trial reporting on caregiver-reported child-level wellbeing. We used a combination of the Kid- and Kiddy-KINDL (parent version) for index children ages three to 12. Putative mediators of the CSI on children's psychosocial wellbeing included harsh parenting, caregiver psychological distress, caregiver wellbeing. Measurements were conducted at baseline, post-intervention and 3-months follow-up.

RESULTS

We demonstrated a statistically significant change in caregiver reported children's psychosocial wellbeing at post-intervention (Mdiff =4.39, 95 % CI = 1.12, 7.65, p < 0.01, d = 0.28) but not at follow-up (Mdiff = -0.97, 95 % CI = -4.27, 2.32, p > 0.05). The proportion of the total effect of the CSI intervention on child psychosocial wellbeing mediated by caregiver distress, caregiver wellbeing and harsh parenting was 77 %.

CONCLUSION

The CSI holds potential for down-stream short-term effect on improving children's psychosocial wellbeing, beyond the previously reported positive caregiver outcomes. This effect was not sustained three months post intervention. The study confirms caregiver wellbeing and parenting support as dual pathways mediating child psychosocial wellbeing. Prospective trial registration: ISRCTN22321773.

Supporting parenting among Syrian refugees in Lebanon: a randomized controlled trial of the caregiver support intervention

BACKGROUND

Parenting interventions in humanitarian settings have prioritized the acquisition of parenting knowledge and skills, while overlooking the adverse effects of stress and distress on parenting-a key mediator of refugee children's mental health. We evaluated the effectiveness of the Caregiver Support Intervention (CSI), which emphasizes caregiver wellbeing together with training in positive parenting.

METHODS

We conducted a two-arm randomized controlled trial of the CSI with Syrian refugees in Lebanon, with an intent-to-treat design, from September 2019-December 2020. A total of 480 caregivers from 240 families were randomized to the CSI or a waitlist control group (1:1). Retention from baseline to endline was 93%. Data on parenting and caregiver psychological wellbeing were collected at baseline, endline, and three-month follow-up. Prospective trial registration: ISRCTN22321773.

RESULTS

We did not find a significant change on overall parenting skills at endline (primary outcome endpoint) (d = .11, p = .126) or at follow-up (Cohen's d = .15, p = .054). We did find a significant effect on overall parenting skills among participants receiving the full intervention-the sub-sample not interrupted by (COVID-19) (d = 0.25, p < .05). The CSI showed beneficial effects in the full sample at endline and follow-up on harsh parenting (d = -.17, p < .05; d = .19, p < .05), parenting knowledge (d = .63, p < .001; d = .50, p < .001), and caregiver distress (d = -.33, p < .001; d = .23, p < .01). We found no effects on parental warmth and responsiveness, psychosocial wellbeing, stress, or stress management. Changes in caregiver wellbeing partially mediated the impact of the CSI on harsh parenting, accounting for 37% of the reduction in harsh parenting.

CONCLUSIONS

The CSI reduced harsh parenting and caregiver distress, and demonstrated the value of addressing caregiver wellbeing as a pathway to strengthening parenting in adversity. These effects were achieved despite a pandemic-related lockdown that impacted implementation, a severe economic crisis, and widespread social unrest. Replication under less extreme conditions may more accurately demonstrate the intervention's full potential.

Separation of Rat Epidermis and Dermis with Thermolysin to Detect Site-Specific Inflammatory mRNA and Protein

Easy-to-use and inexpensive techniques are needed to determine the site-specific production of inflammatory mediators and neurotrophins during skin injury, inflammation, and/or sensitization. The goal of this study is to describe an epidermal-dermal separation protocol using thermolysin, a proteinase that is active at 4 °C. To illustrate this procedure, Sprague Dawley rats are anesthetized, and right hind paws are injected with carrageenan. Six and twelve hours after injection, rats with inflammation and naïve rats are euthanized, and a piece of hind paw, glabrous skin is placed in cold Dulbecco's Modified Eagle Medium. The epidermis is then separated at the basement membrane from the dermis by thermolysin in PBS with calcium chloride. Next, the dermis is secured by microdissection forceps, and the epidermis is gently teased away. Toluidine blue staining of tissue sections show that the epidermis is separated cleanly from the dermis at the basement membrane. All keratinocyte cell layers remain intact, and the epidermal rete ridges along with indentations from dermal papillae are clearly observed. Qualitative and real-time RT-PCR is used to determine nerve growth factor and interleukin-6 expression levels. Western blotting and immunohistochemistry are finally performed to detect amounts of nerve growth factor. This report illustrates that cold thermolysin digestion is an effective method to separate epidermis from dermis for evaluation of mRNA and protein alterations during inflammation.

Subcellular localization of neuronal nuclei (NeuN) antigen in size and calcitonin gene-related peptide (CGRP) populations of dorsal root ganglion (DRG) neurons during acute peripheral inflammation

Pseudo-unipolar cell bodies of somatosensory primary neurons are located in the dorsal root ganglia (DRG). The somatic and peripheral domains of DRG neurons are often studied in sensory pain research to understand molecular mechanisms involved in the activation of pain and maintenance of inflammation. Adjuvant-induced arthritis (AIA) is an inflammatory model that elicits a robust and rapid onset immune response with a maximal swelling period of 24-48 h and persisting for several weeks. The AIA model in the hind paw of the rat elicits a potent inflammatory response of the dermis and epidermis, leading to protein expression changes for sensitization of many DRG neurons; however, it is unknown if the AIA model in the hind paw of the rat induces DRG neuronal injury, necrosis, or apoptosis at the somatic level. Neuronal nuclei (NeuN) antigen is a biomarker for post-mitotic neurons, neuronal identification, protein alterations, injury, and loss. Calcitonin gene-related peptide (CGRP) is expressed in C and Aδ DRG neurons, a subset of DRG neurons known to play a role in peripheral sensitization. The focus of this research was to evaluate the expression pattern of NeuN immunoreactivity, in size (soma) and CGRP subpopulations of DRG neurons in naïve and inflamed groups. Confirmed by both immunofluorescence and immunoprecipitation, DRG neuronal expression of NeuN was localized to nuclear and cytoplasmic subcellular compartments. NeuN increased within the nucleus of small CGRP positive DRG neurons during inflammation, indicating a potential role for NeuN in a subset of nociceptive neurons.

Open-source method of image cytometry in dorsal root ganglia tissue with immunofluorescence

Immunohistochemistry (IHC) is a valuable tool in clinical and biological research for evaluating proteins and other antigens in spatially bound tissue. In neuroinflammatory pain research, primary afferent neurons of the dorsal root ganglion (DRG) are studied to understand molecular signaling mechanisms involved in nociception (pain) and inflammation. Measuring IHC (immunofluorescence) in DRG neurons requires manual hand tracing of nuclear and somatic boundaries, which is laborious, error-prone, and may require several weeks to collect the appropriate sample size with a mouse or pen-input display monitor. To overcome these limitations and increase standardization of sampling and measurement, we employed a reliable neuronal cytoplasmic reporter, exclusive to DRG neuronal soma, in a semi-automated algorithm-based approach of Image Cytometry in rat DRG (IC-DRG). The resulting output images are binary nuclear and somatic masks of DRG neurons, defining boundaries of measurement for CellProfiler and manually scored at 94% accurate. Herein, we successfully show a novel approach of automated image analysis for DRG neurons using a robust ImageJ/FIJI script, overcoming morphological variability and imaging artifacts native to imaging frozen tissue sections processed with immunofluorescence.

Supporting Syrian families displaced by armed conflict: A pilot randomized controlled trial of the Caregiver Support Intervention

BACKGROUND

The impact of armed conflict and displacement on children's mental health is strongly mediated by compromised parenting stemming from persistently high caregiver stress. Parenting interventions for refugees emphasize the acquisition of parenting knowledge and skills, while overlooking the deleterious effects of chronic stress on parenting. War Child Holland's Caregiver Support Intervention (CSI) aims to strengthen parenting by lowering stress and improving psychosocial wellbeing among refugee parents, while also increasing knowledge and skill related to positive parenting. The CSI is a nine-session group intervention delivered by non-specialist providers.

OBJECTIVE

We describe the findings of a two-arm pilot randomized controlled trial of the CSI with Syrian refugees in Lebanon. The primary aim was to test the feasibility of our study methodology prior to conducting a definitive RCT.

METHODS

We recruited 78 families (151 parents), who were randomized to the CSI or a waitlist control group. Data were collected at baseline and post-intervention.

RESULTS

Randomization was successful, retention was high (99 %), as was intervention completion (95 % among women, 86 % among men). Implementation fidelity was excellent. Blinding was largely, though not completely effective. The CSI group showed significantly increased parental warmth and responsiveness, decreased harsh parenting, lowered stress and distress, improved psychosocial wellbeing, and improved stress management. CSI parents reported increased child psychosocial wellbeing. Control families showed no significant change on any variable.

CONCLUSIONS

Findings demonstrate the feasibility of our methodology for a definitive RCT, and suggest that the CSI shows promise as a scalable approach to strengthening parenting in refugee communities. Trial registration # ISRCTN33665023.

0462 Identifying and Characterizing Insomnia Symptom Groups Across the Deployment Cycle in Current Army Soldiers

Introduction

Most research conducted on insomnia and its development in military personnel focuses on cross-sectional data, precluding examination of the course of sleep changes over time. The present study characterized Army Soldiers based on insomnia symptom status trajectory from pre to post-deployment and explored baseline factors predictive of these trajectories in a sample of 7,245 soldiers across 3 Brigade Combat Teams.

Methods

Data were analyzed from the Army Study to Assess Risk and Resilience in Service members (STARRS)-All-Army Study (AAS) Pre Post Deployment Study, using surveys that captured 1-2 months pre-deployment, during deployment, and 6-months post-deployment. Insomnia symptom status was defined at each timepoint as insomnia symptoms that interfered with one or more domains of functioning at least some of the time in the past month. Theoretically-derived variables linked to sleep disturbance were selected as predictors of insomnia symptom trajectory and evaluated using a general linear selection model.

Results

Four trajectories characterized the majority of the sample: ‘good sleepers’ (no insomnia symptoms across time; 44.4%), ‘non-remitting new onset insomnia’ (no pre-deployment insomnia, developed insomnia symptoms during deployment that remained at 6 months; 22.8%), ‘deployment-only insomnia symptoms’ (no pre-deployment insomnia, developed insomnia during deployment but recovered by follow-up; 12.8%), and ‘chronic insomnia’ (insomnia both pre- and post-deployment; 7.4%). Several pre-deployment factors predicted insomnia trajectory, the strongest of which were past six-month attention deficit disorder symptoms, number of lifetime exposures to potentially traumatic events, and past month depression symptoms.

Conclusion

Insomnia is one of the most common reasons that military personnel seek behavioral health treatment and is associated with poorer military readiness. Better characterization and identification of insomnia symptoms over time can improve intervention during post-deployment transitions, particularly for those with new onset insomnia that does not remit.

Support

Cooperative agreement U01MH087981 (Department of the Army; U.S. Department of Health and Human Services, National Institutes of Health, National Institute of Mental Health); U.S. Department of Veterans Affairs, Clinical Science Research and Development-IK2CX001874-PI:Katherine E. Miller, IK2CX001501-PI:Elaine M. Boland; Rehabilitation Research and Development-1IK2RX001836-PI:Elizabeth A. Klingaman. The views expressed here are those of the authors and do not represent the Department of Veterans Affairs.

Protocol for a randomized control trial of the caregiver support intervention with Syrian refugees in Lebanon

Background

There is evidence that chronic stress negatively impacts parenting among refugees and other war-affected communities. Persistent parental stress and distress may lead to unresponsive, anxious, or overly harsh parenting and a corresponding increase in emotional and behavior problems among children. Most parenting interventions emphasize the acquisition of knowledge and skills; however, this overlooks the deleterious effects of chronic stress on parenting. The Caregiver Support Intervention (CSI) aims to strengthen quality of parenting skills by lowering stress and improving psychosocial wellbeing among refugee caregivers of children aged 3–12 years, while also increasing knowledge and skills related to positive parenting. The CSI is a nine-session psychosocial group intervention delivered by non-specialist providers. It is intended for all adult primary caregivers of children in high-adversity communities, rather than specifically targeting caregivers already showing signs of elevated distress.

Methods/design

The primary objective of this study is to assess the effectiveness of the CSI through a parallel group randomized controlled study with Syrian refugee families in North Lebanon. Participants will be primary caregivers of children aged 3–12 years, with one index child per family. Families will be randomized to the CSI or a waitlist control group.

A total of 240 families (480 caregivers) will be recruited into the study. Randomization will be at the family level, and CSI groups will be held separately for women and men. The study will be implemented in two waves. Outcomes for both arms will be assessed at baseline, post-intervention, and at a 3-month follow-up. The primary outcome is quality of parenting skills. Secondary outcomes include parental warmth and sensitivity, harsh parenting, parenting knowledge, and child psychosocial wellbeing. Putative mediators of the CSI on parenting are caregiver stress, distress, psychosocial wellbeing, and stress management.

Discussion

This trial may establish the CSI as an effective intervention for strengthening parenting in families living in settings of high adversity, particularly refugee communities.

Trial registration

International Society for the Registration of Clinical Trials, ISRCTN22321773. Registered on 5 August 2019

The Aerobic and Cognitive Exercise Study (ACES) for Community-Dwelling Older Adults With or At-Risk for Mild Cognitive Impairment (MCI): Neuropsychological, Neurobiological and Neuroimaging Outcomes of a Randomized Clinical Trial

Prior research has found that cognitive benefits of physical exercise and brain health in older adults may be enhanced when mental exercise is interactive simultaneously, as in exergaming. It is unclear whether the cognitive benefit can be maximized by increasing the degree of mental challenge during exercise. This randomized clinical trial (RCT), the Aerobic and Cognitive Exercise Study (ACES) sought to replicate and extend prior findings of added cognitive benefit from exergaming to those with or at risk for mild cognitive impairment (MCI). ACES compares the effects of 6 months of an exer-tour (virtual reality bike rides) with the effects of a more effortful exer-score (pedaling through a videogame to score points). Fourteen community-dwelling older adults meeting screening criteria for MCI (sMCI) were adherent to their assigned exercise for 6 months. The primary outcome was executive function, while secondary outcomes included memory and everyday cognitive function. Exer-tour and exer-score yielded significant moderate effects on executive function (Stroop A/C; d's = 0.51 and 0.47); there was no significant interaction effect. However, after 3 months the exer-tour revealed a significant and moderate effect, while exer-score showed little impact, as did a game-only condition. Both exer-tour and exer-score conditions also resulted in significant improvements in verbal memory. Effects appear to generalize to self-reported everyday cognitive function. Pilot data, including salivary biomarkers and structural MRI, were gathered at baseline and 6 months; exercise dose was associated with increased BDNF as well as increased gray matter volume in the PFC and ACC. Improvement in memory was associated with an increase in the DLPFC. Improved executive function was associated with increased expression of exosomal miRNA-9. Interactive physical and cognitive exercise (both high and low mental challenge) yielded similarly significant cognitive benefit for adherent sMCI exercisers over 6 months. A larger RCT is needed to confirm these findings. Further innovation and clinical trial data are needed to develop accessible, yet engaging and effective interventions to combat cognitive decline for the growing MCI population.

ClinicalTrials.gov ID: NCT02237560

Modeling molecular mechanisms in the axon

Axons are living systems that display highly dynamic changes in stiffness, viscosity, and internal stress. However, the mechanistic origin of these phenomenological properties remains elusive. Here we establish a computational mechanics model that interprets cellular-level characteristics as emergent properties from molecular-level events. We create an axon model of discrete microtubules, which are connected to neighboring microtubules via discrete crosslinking mechanisms that obey a set of simple rules. We explore two types of mechanisms: passive and active crosslinking. Our passive and active simulations suggest that the stiffness and viscosity of the axon increase linearly with the crosslink density, and that both are highly sensitive to the crosslink detachment and reattachment times. Our model explains how active crosslinking with dynein motors generates internal stresses and actively drives axon elongation. We anticipate that our model will allow us to probe a wide variety of molecular phenomena-both in isolation and in interaction-to explore emergent cellular-level features under physiological and pathological conditions.

Characterization of glutamatergic neurons in the rat atrial intrinsic cardiac ganglia that project to the cardiac ventricular wall

The intrinsic cardiac nervous system modulates cardiac function by acting as an integration site for regulating autonomic efferent cardiac output. This intrinsic system is proposed to be composed of a short cardio-cardiac feedback control loop within the cardiac innervation hierarchy. For example, electrophysiological studies have postulated the presence of sensory neurons in intrinsic cardiac ganglia (ICG) for regional cardiac control. There is still a knowledge gap, however, about the anatomical location and neurochemical phenotype of sensory neurons inside ICG. In the present study, rat ICG neurons were characterized neurochemically with immunohistochemistry using glutamatergic markers: vesicular glutamate transporters 1 and 2 (VGLUT1; VGLUT2), and glutaminase (GLS), the enzyme essential for glutamate production. Glutamatergic neurons (VGLUT1/VGLUT2/GLS) in the ICG that have axons to the ventricles were identified by retrograde tracing of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) injected in the ventricular wall. Co-labeling of VGLUT1, VGLUT2, and GLS with the vesicular acetylcholine transporter (VAChT) was used to evaluate the relationship between post-ganglionic autonomic neurons and glutamatergic neurons. Sequential labeling of VGLUT1 and VGLUT2 in adjacent tissue sections was used to evaluate the co-localization of VGLUT1 and VGLUT2 in ICG neurons. Our studies yielded the following results: (1) ICG contain glutamatergic neurons with GLS for glutamate production and VGLUT1 and 2 for transport of glutamate into synaptic vesicles; (2) atrial ICG contain neurons that project to ventricle walls and these neurons are glutamatergic; (3) many glutamatergic ICG neurons also were cholinergic, expressing VAChT; (4) VGLUT1 and VGLUT2 co-localization occurred in ICG neurons with variation of their protein expression level. Investigation of both glutamatergic and cholinergic ICG neurons could help in better understanding the function of the intrinsic cardiac nervous system.

Determinants of Children's Mental Health in War-Torn Settings: Translating Research Into Action

Research on the mental health and psychosocial wellbeing of children in conflict-affected settings has undergone a significant paradigm shift in recent years. Earlier studies based on a war exposure model primarily emphasized the effects of direct exposure to armed conflict; this has gradually given way to a broader understanding of the diverse pathways by which organized violence affects children. A robustly supported comprehensive model includes risk factors at multiple points in time (prior war exposure, ongoing daily stressors) and at all levels of the social ecology. In particular, findings suggest that material deprivation and a set of family variables, including harsh parenting, parental distress, and witnessing intimate partner violence, are important mediators of the relationship between armed conflict and children's wellbeing. To date, however, interventions aimed at supporting war-affected children's wellbeing, both preventive and treatment-focused, have focused primarily on direct work with children, while paying only modest attention to ongoing risk factors in their families and broader environments. Possible reasons for the ongoing prioritization of child-focused interventions are considered, and examples are provided of recent evidence-based interventions that have reduced toxic stressors (harsh parenting and the use of violent discipline by teachers) in conflict-affected communities.

Evaluating the Analgesic Effect of the GLS Inhibitor 6-Diazo-5-Oxo-L-Norleucine in Vivo

Glutamate is an excitatory neurotransmitter, produced by its synthetic enzyme, glutaminase (GLS), and packaged by vesicular transporters (VGluT2) into synaptic vesicles. Primary sensory peripheral nerve and spinal synaptic terminals release glutamate during nociceptive (pain) signaling. In post-incisional and inflammation models in rats, GLS and VGluT2 production is elevated in dorsal root ganglion neuronal cell bodies and transported to peripheral and spinal terminals for increased glutamate synthesis and release. 6-Diazo-5-oxo-l-norleucine (DON) is a GLS inhibitor that produces long lasting pain relief when applied to the inflamed paw of arthritic rats, but its effect in a post-incisional model has not been evaluated. In this study, we examined the analgesic efficacy of DON in a surgical incision model by measuring thermal latency and mechanical allodynia. Following behavioral evaluation, we examined the skin for VGluT2, GLS and glutamate immunoreactivity (ir). Our findings revealed that VGluT2-ir is elevated in the stratum lucidum by approximately 19%, 64 hours post-surgical incision and attenuated by approximately 5.4% after the administration of DON. During that same period GLS-ir was elevated in dermal nerve fibers by 52% and was attenuated by approximately 27.9% after the application of DON. Additionally, glutamate-ir was elevated in epidermal nerve fibers by 35% after incision and attenuated by approximately 23% after the administration of DON. Behavioral testing 24 and 48 hours after a single local administration of DON showed five out of six animals having an analgesic response to mechanical allodynia, but not to thermal hyperalgesia. Following a surgical incision, the area of injury shows increased VGluT2-, GLS-, glutamate-ir, mechanical allodynia and no change in thermal latency. After the application of the GLS inhibitor, DON, nerve fiber of the skin showed decreased VGluT2, GLS, and glutamate-ir. Furthermore, post-incision DON treated animals exhibited decreased mechanical allodynia with no change in thermal latency when compared to control animals.

Evaluating the Toxicity of the Analgesic Glutaminase Inhibitor 6-Diazo-5-Oxo-L-Norleucine in vitro and on Rat Dermal Skin Fibroblasts

6-diazo-5-oxo-l-norleucine (DON) is a glutamine antagonist produced naturally by Streptomyces. It inhibits several glutamine-dependent enzyme pathways. Of particular note is its inhibitory effect on the mitochondrial enzyme, glutaminase (GLS), the primary producer of neuronal glutamate. Glutamate is an excitatory neurotransmitter released by primary sensory peripheral nerve terminals and spinal synaptic terminals during pain signaling. Previous work using the tail incision and inflammatory models of pain has demonstrated that a single application of the glutaminase inhibitor, DON, into a surgical incision or the paw of arthritic animals results in pain relief. Even though this compound shows promise as a therapeutic agent, limited data exist regarding its dermal toxicity. As a first approach, we evaluated the effect of several concentrations of DON, on the viability, mitochondrial oxidative capacity and proliferation of rat skin fibroblasts, and then examined the effect of DON after incubation with human liver microsomes on proliferation. Finally, we evaluated DON treated rat skin (tail and hind paw) for cellular necrosis, inflammation and mitotic bodies. No significant effects (p > 0.05) of DON were noted on apoptosis, necrosis, and mitochondrial activity in experiments with cultured rat skin fibroblasts. Flow cytometry revealed the absence of apoptosis in cells treated at the IC₅₀ of 232.5 μM. Enhanced toxicity post-exposure to human microsomes was not observed when compared to DON alone. The H&E staining of the rat skin revealed no obvious pathology in the DON treatment group (10 mM). DON has no/minimal cellular toxicity in vitro on dermal fibroblasts at concentrations that effectively provide analgesia. The local application of concentrations greater than the in vitro IC₅₀ for DON revealed no in vivo skin toxicity. These data provide results indicating zero-to-minimal cellular toxicity with DON and support the further investigation of DON as an analgesic.

Organic molecules in the Sheepbed Mudstone, Gale Crater, Mars

The Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory Curiosity rover is designed to conduct inorganic and organic chemical analyses of the atmosphere and the surface regolith and rocks to help evaluate the past and present habitability potential of Mars at Gale Crater. Central to this task is the development of an inventory of any organic molecules present to elucidate processes associated with their origin, diagenesis, concentration, and long-term preservation. This will guide the future search for biosignatures. Here we report the definitive identification of chlorobenzene (150-300 parts per billion by weight (ppbw)) and C₂ to C₄ dichloroalkanes (up to 70 ppbw) with the SAM gas chromatograph mass spectrometer (GCMS) and detection of chlorobenzene in the direct evolved gas analysis (EGA) mode, in multiple portions of the fines from the Cumberland drill hole in the Sheepbed mudstone at Yellowknife Bay. When combined with GCMS and EGA data from multiple scooped and drilled samples, blank runs, and supporting laboratory analog studies, the elevated levels of chlorobenzene and the dichloroalkanes cannot be solely explained by instrument background sources known to be present in SAM. We conclude that these chlorinated hydrocarbons are the reaction products of Martian chlorine and organic carbon derived from Martian sources (e.g., igneous, hydrothermal, atmospheric, or biological) or exogenous sources such as meteorites, comets, or interplanetary dust particles.

KEY POINTS

First in situ evidence of nonterrestrial organics in Martian surface sediments Chlorinated hydrocarbons identified in the Sheepbed mudstone by SAM Organics preserved in sample exposed to ionizing radiation and oxidative condition.

Organic molecules in the Sheepbed Mudstone, Gale Crater, Mars

The Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory Curiosity rover is designed to conduct inorganic and organic chemical analyses of the atmosphere and the surface regolith and rocks to help evaluate the past and present habitability potential of Mars at Gale Crater. Central to this task is the development of an inventory of any organic molecules present to elucidate processes associated with their origin, diagenesis, concentration, and long-term preservation. This will guide the future search for biosignatures. Here we report the definitive identification of chlorobenzene (150-300 parts per billion by weight (ppbw)) and C₂ to C₄ dichloroalkanes (up to 70 ppbw) with the SAM gas chromatograph mass spectrometer (GCMS) and detection of chlorobenzene in the direct evolved gas analysis (EGA) mode, in multiple portions of the fines from the Cumberland drill hole in the Sheepbed mudstone at Yellowknife Bay. When combined with GCMS and EGA data from multiple scooped and drilled samples, blank runs, and supporting laboratory analog studies, the elevated levels of chlorobenzene and the dichloroalkanes cannot be solely explained by instrument background sources known to be present in SAM. We conclude that these chlorinated hydrocarbons are the reaction products of Martian chlorine and organic carbon derived from Martian sources (e.g., igneous, hydrothermal, atmospheric, or biological) or exogenous sources such as meteorites, comets, or interplanetary dust particles.

KEY POINTS

First in situ evidence of nonterrestrial organics in Martian surface sediments Chlorinated hydrocarbons identified in the Sheepbed mudstone by SAM Organics preserved in sample exposed to ionizing radiation and oxidative condition.

Expression of Glutaminase and Vesicular Glutamate Transporter Type 2 Immunoreactivity in Rat Sacral Dorsal Root Ganglia Following a Surgical Tail Incision

Glutamate is an excitatory neurotransmitter, released by primary sensory peripheral nerve and spinal synaptic terminals during nociceptive (pain) signaling. The primary source of neurotransmitter, glutamate, is provided from its synthetic enzyme, glutaminase (GLS). Neurotransmitter glutamate is packaged into synaptic vesicles in nociceptive neurons by the vesicular glutamate transporter 2 (VGluT2). Little is known, however, what effect a surgical incision has on GLS and VGluT2 in primary afferent neurons. In this study, an aseptic, midline incision in the proximal one-third of the rat-tail was examined to determine whether sacral dorsal root ganglia innervate the area of surgical incision, utilizing the retrograde tracer Fluoro-Gold™. Subsequently, the amount of VGluT2 and GLS immunoreactivity (IR) in sacral dorsal root ganglia (DRG) was evaluated using immunofluorescence with image analysis and Western immunoblotting with density analysis. GLS messenger RNA (mRNA) changes were evaluated using real-time reverse transcriptase polymerase chain reaction (RT²-PCR). Our findings revealed that sacral-1 (S₁) DRG neurons innervate the area of surgical incision. Both GLS and VGluT2-ir are elevated post-surgical incision in S₁ DRG neurons for up to 72 hours, while GLS mRNA levels rapidly decreased post-incision and remain depressed for at least 96 hours. Following a surgical incision of the tail, sacral DRGs rapidly deplete their available supply of GLS mRNA and alter their production of the synthetic enzyme, GLS and the vesicular transporter, VGluT2. The rapid use of GLS mRNA and subsequent elevation of GLS protein, along with VGluT2 protein may result in both increased glutamate production and release at peripheral and central processes contributing to primary and secondary sensitization, respectively.

Intermittent vs Continuous Administration of Nerve Growth Factor to Injured Medial Septal Cholinergic Neurons in Rat Basal Forebrain

Many medial septal neurons of the basal forebrain are dependent on nerve growth factor (NGF) from the hippocampus for survival and maintenance of a cholinergic phenotype. When deprived of their source of NGF by axotomy, medial septal neuronal cell bodies atrophy and lose their cholinergic markers. This is similar to what is observed in the basal forebrain during Alzheimer’s disease (AD). In the present study, medial septal neurons were axotomized in female rats by way of a fimbria/fornix lesion. For fourteen days following axotomy, varying NGF doses (1 – 250 μg/ml) were administered to the lateral cerebral ventricle with either mini-osmotic infusion or daily injection. The responsiveness of medial septal neurons was evaluated with choline acetyltransferase immunohistochemistry. Within the mini-osmotic pumps, NGF activity diminished greatly during the first five days of implantation, but increased dramatically in the CSF after five days of infusion. The responsiveness of medial septal neurons to NGF was dose dependent and the ED₅₀ for NGF injection was determined to be 14.08 μg/ml compared to 27.60 μg/ml for NGF infusion. Intermittent injections at varying intervals were evaluated with 30 μg/ml NGF over a fourteen-day time period (2, 3, 6, or 12 injections). No differences occurred in the number of choline acetyltransferase neurons from rats that received weekly injections to those that received daily injections of NGF. NGF administration has been suggested as a therapy for AD. The results of these studies continue to highlight the need for NGF stability within the delivery system and AD patient CSF, the choice of delivery system, frequency of administration, and the NGF dose for maintaining basal forebrain cholinergic neurons during AD.

Volatile and organic compositions of sedimentary rocks in Yellowknife Bay, Gale crater, Mars

H2O, CO2, SO2, O2, H2, H2S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H2O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO2. Concurrent evolution of O2 and chlorinated hydrocarbons suggests the presence of oxychlorine phase(s). Sulfides are likely sources for sulfur-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic carbon sources may be preserved in the mudstone; however, the carbon source for the chlorinated hydrocarbons is not definitively of martian origin.

Potential mechanisms for hypoalgesia induced by anti-nerve growth factor immunoglobulin are identified using autoimmune nerve growth factor deprivation

Nerve growth factor (NGF) antagonism has long been proposed as a chronic pain treatment. In 2010, the FDA suspended clinical trials using tanezumab, a humanized monoclonal anti-NGF antibody, to treat osteoarthritis due to worsening joint damage in 16 patients. Increased physical activity in the absence of acute pain which normally prevents self-harm was purported as a potential cause. Such an adverse effect is consistent with an extension of tanezumab's primary mechanism of action by decreasing pain sensitivity below baseline levels. In animal inflammatory pain models, NGF antagonism decreases intraepidermal nerve fiber (IENF) density and attenuates increases in expression of nociception-related proteins, such as calcitonin gene-related peptide (CGRP) and substance P (SP). Little is known of the effects of NGF antagonism in noninflamed animals and the hypoalgesia that ensues. In the current study, we immunized rats with NGF or cytochrome C (cytC) and examined (1) nocifensive behaviors with thermal latencies, mechanical thresholds, the hot plate test, and the tail flick test, (2) IENF density, and (3) expression of CGRP, SP, voltage-gated sodium channel 1.8 (Nav1.8), and glutaminase in subpopulations of dorsal root ganglion (DRG) neurons separated by size and isolectin B4 (IB4) labeling. Rats with high anti-NGF titers had delayed responses on the hot plate test but no other behavioral abnormalities. Delayed hot plate responses correlated with lower IENF density. CGRP and SP expression was decreased principally in medium (400-800 μm(2)) and small neurons (<400 μm(2)), respectively, regardless of IB4 labeling. Expression of Nav1.8 was only decreased in small and medium IB4 negative neurons. NGF immunization appears to result in a more profound antagonism of NGF than tanezumab therapy, but we hypothesize that decreases in IENF density and nociception-related protein expression are potential mechanisms for tanezumab-induced hypoalgesia.

Glutamate pharmacology and metabolism in peripheral primary afferents: physiological and pathophysiological mechanisms

In addition to using glutamate as a neurotransmitter at central synapses, many primary sensory neurons release glutamate from peripheral terminals. Primary sensory neurons with cell bodies in dorsal root or trigeminal ganglia produce glutaminase, the synthetic enzyme for glutamate, and transport the enzyme in mitochondria to peripheral terminals. Vesicular glutamate transporters fill neurotransmitter vesicles with glutamate and they are shipped to peripheral terminals. Intense noxious stimuli or tissue damage causes glutamate to be released from peripheral afferent nerve terminals and augmented release occurs during acute and chronic inflammation. The site of action for glutamate can be at the autologous or nearby nerve terminals. Peripheral nerve terminals contain both ionotropic and metabotropic excitatory amino acid receptors (EAARs) and activation of these receptors can lower the activation threshold and increase the excitability of primary afferents. Antagonism of EAARs can reduce excitability of activated afferents and produce antinociception in many animal models of acute and chronic pain. Glutamate injected into human skin and muscle causes acute pain. Trauma in humans, such as arthritis, myalgia, and tendonitis, elevates glutamate levels in affected tissues. There is evidence that EAAR antagonism at peripheral sites can provide relief in some chronic pain sufferers.

Rates and impact of trauma and current stressors among Darfuri refugees in Eastern Chad

Darfur refugees face hardships associated with chronic displacement, including lack of basic needs and safety concerns. Psychiatric research on refugees has focused on trauma, but daily stressors may contribute more to variance in distress. This article reports rates of past trauma and current stressors among Darfur refugees and gauges the contribution of each to psychological distress and functional impairment. A representative sample of 848 Darfuris in 2 refugee camps were interviewed about traumatic events, stressors faced in the camps, psychological distress, and functional impairment. Basic needs and safety concerns were more strongly correlated with measures of distress (rs = .19-.31) than were war-related traumatic events (rs = .09-.20). Hierarchical regression supported models in which effects of trauma on distress were mediated by current stressors. Although war-related traumatic events are the initial causes of refugees' hardship, findings suggest that the day-to-day challenges and concerns in camps mediate psychological distress associated with these events.

Peripheral inhibition of glutaminase reduces carrageenan-induced Fos expression in the superficial dorsal horn of the rat

In inflamed tissue, the levels of the excitatory amino acid glutamate are increased. Glutamate sensitizes peripheral axons of primary afferent neurons during inflammation leading to decreased firing threshold and hyperexcitability. One proposed source of glutamate is the primary afferent. Antagonizing glutamate receptors on peripheral axons of primary afferents during inflammation provides analgesia in animals and humans. The enzyme glutaminase is used by primary sensory neurons to convert glutamine to glutamate, and peripheral inhibition of glutaminase with 6-diazo-5-oxo-l-norleucine (DON) provides long-lasting analgesia during inflammation. In this study, we measured the effects of glutaminase inhibition on carrageenan-induced spinal Fos expression. Rats were given intraplantar injections of carrageenan and treated locally with either vehicle or DON. After 3h of inflammation, hind paw swelling and spinal expression of Fos were examined. CellProfiler was used to automate Fos nuclei counting in five laminar groupings in the spinal cord (I-II, III-IV, V-VI, VII-IX, X). Carrageenan increased hind paw thickness by approximately 70% and spinal Fos expression in superficial (I-II) and deep (V-VI) laminae by 10-fold and 5-fold, respectively. Treatment with DON reduced hind paw swelling by approximately 13% and suppressed Fos expression in the laminae I-II by approximately 54%, but not the deep laminae. Our results further support the notion of glutamate as a peripheral inflammatory mediator and indicate that glutaminase should be considered as a novel therapeutic target for treatment of inflammatory pain.

Fixative composition alters distributions of immunoreactivity for glutaminase and two markers of nociceptive neurons, Nav1.8 and TRPV1, in the rat dorsal root ganglion

Most, if not all, dorsal root ganglion (DRG) neurons use the neurotransmitter glutamate. There are, however, conflicting reports of the percentages of DRG neurons that express glutaminase (GLS), the enzyme that synthesizes glutamate, ranging from 30% to 100% of DRG neurons. Defining DRG neuron populations by the expression of proteins like GLS, which indicates function, is routinely accomplished with immunolabeling techniques. Proper characterization of DRG neuron populations relies on accurate detection of such antigens. It is known intuitively that fixation can alter immunoreactivity (IR). In this study, we compared the effects of five formaldehyde concentrations between 0.25% and 4.0% (w/v) and five picric acid concentrations between 0.0% and 0.8% (w/v) on the IR of GLS, the voltage-gated sodium channel 1.8 (Na(v)1.8), and the capsaicin receptor TRPV1. We also compared the effects of five incubation time lengths from 2 to 192 hr, in primary antiserum on IR. Lowering formaldehyde concentration elevated IR for all three antigens, while raising picric acid concentration increased Na(v)1.8 and TRPV1 IR. Increasing IR improved detection sensitivity, which led to higher percentages of labeled DRG neurons. By selecting fixation conditions that optimized IR, we found that all DRG neurons express GLS, 69% of neurons express Na(v)1.8, and 77% of neurons express TRPV1, indicating that some previous studies may have underestimated the percentages of DRG neurons expressing these proteins. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials.

War exposure, daily stressors, and mental health in conflict and post-conflict settings: bridging the divide between trauma-focused and psychosocial frameworks

This paper seeks to bridge the divisive split between advocates of trauma-focused and psychosocial approaches to understanding and addressing mental health needs in conflict and post-conflict settings by emphasizing the role that daily stressors play in mediating direct war exposure and mental health outcomes. The authors argue that trauma-focused advocates tend to overemphasize the impact of direct war exposure on mental health, and fail to consider the contribution of stressful social and material conditions (daily stressors). Drawing on the findings of recent studies that have examined the relationship of both war exposure and daily stressors to mental health status, a model is proposed in which daily stressors partially mediate the relationship of war exposure to mental health. Based on that model, and on the growing body of research that supports it, an integrative, sequenced approach to intervention is proposed in which daily stressors are first addressed, and specialized interventions are then provided for individuals whose distress does not abate with the repair of the social ecology.

The validity and clinical utility of post-traumatic stress disorder in Afghanistan

This study examined the validity and utility of PTSD among 320 adults in Afghanistan. Findings support the validity of PTSD in this cultural context: PTSD symptoms were highly prevalent, shared common variance, and correlated as expected with exposure to traumatic stress. However, only limited support was found for the clinical utility of PTSD. Other types of psychiatric symptomatology, including depression and a culturally specific measure of general distress, correlated more highly with traumatic stress than did PTSD; and PTSD accounted for limited variance in functioning beyond that explained by depression and general distress. Implications for research and intervention are considered.

Daily stressors, war experiences, and mental health in Afghanistan

Working in Afghanistan's capital city of Kabul, the authors assessed the relative contribution of daily stressors and war-related experiences of violence and loss to levels of depression, PTSD, impaired functioning, and a culturally specific measure of general psychological distress. For women, daily stressors were a better predictor than war experiences of all mental health outcomes except for PTSD; for men, daily stressors were a better predictor of depression and functional impairment, while war experiences and daily stressors were similarly predictive of general distress. For men, daily stressors moderated the relationship between war experiences and PTSD, which was significant only under conditions of low daily stress. The study's implications for research and intervention in conflict and post-conflict settings are considered.

Glutamate and metabotropic glutamate receptors associated with innervation of the uterine cervix during pregnancy: Receptor antagonism inhibits c-fos expression in rat lumbosacral spinal cord at parturition

Dorsal root ganglia (DRG) neurons connect the spinal cord and uterine cervix, and are activated at parturition with subsequent stimulation of secondary neurons in the spinal dorsal horn and autonomic areas. Neuropeptide neurotransmitters and receptors have been studied in these areas, but amino acid transmitters, e.g., glutamate, an excitatory neurotransmitter involved in sensory and nociceptive processing, have not been characterized. To determine if glutamate is involved in innervation of the cervix, rats were examined for markers of glutamatergic neurons in the L6-S1 spinal cord, DRG and cervix. Metabotropic glutamate receptors mGluR5 in the spinal dorsal horn and their expression over pregnancy were examined in pregnant rats and pregnant rats treated continuously with an antagonist of mGluR5, 2-methyl-6-(phenylethynyl) pyridine (MPEP). Rats were allowed to deliver pups to determine if the antagonist altered the expression of an early response gene protein, Fos, in the L6-S1 cord. Immunohistochemistry showed glutamate- and vesicular glutamate transporter1 (VGluT1)-positive fibers in the cervix, glutamate- and VGluT1-expressing neurons in the DRG, some of which also exhibited retrograde tracer from cervical injections, and VGluT1 and mGluR5 immunoreactivities in the L6-S1 spinal dorsal horns. Expression of mGluR5 receptors increased over pregnancy. Fos-positive neurons were present among mGluR5-immunoreactivity in the spinal dorsal horn. Parturition-induced Fos-positive neurons in the spinal cords were abundant in control rats, but were reduced by 70% in MPEP-treated animals. These results suggest that glutamate is likely involved in the transmission of sensory signals, possibly pain, from the cervix to the spinal cord at parturition.

Evidence of relaxation and spontaneous transition to a high-confinement state in high-beta steady-state plasmas sustained by rotating magnetic fields

Evidence of relaxation has appeared, for the first time, in the extremely high-beta, steady-state field-reversed configuration plasma states driven by rotating magnetic fields (RMF) in the translation, confinement, and sustainment experiment. The plasma self-organizes into a near-force-free state in the vicinity of the magnetic axis, with significant improvement in confinement. Associated with this change in magnetic topology is the appearance of an axial RMF component; this would, in turn, generate a current drive in the poloidal direction, thus sustaining the magnetic helicity. A newly developed two-dimensional "equilibrium-lite" model is employed to analyze the magnetic properties of the final high-confinement state, and shows a large q and a significant magnetic shear in the core.

Responses of thoracic spinal neurons to activation and desensitization of cardiac TRPV1-containing afferents in rats

The purpose of this study was to examine how upper thoracic spinal neurons responded to activation and desensitization of cardiac transient receptor potential vanilloid-1 (TRPV1)-containing afferent fibers. Extracellular potentials of single T3 spinal neurons were recorded in pentobarbital-anesthetized, paralyzed, and ventilated male rats. To activate cardiac nociceptive receptors, a catheter was placed in the pericardial sac to administer various chemicals: bradykinin (BK; 10 μg/ml, 0.2 ml), capsaicin (CAP, 10 μg/ml, 0.2 ml), or a mixture of algesic chemicals (AC; 0.2 ml) containing adenosine 10−3 M, BK, serotonin, histamine, and PGE2, 10−5 M for each. Spinal neurons that responded to intrapericardial BK and/or CAP were used in this study. Results showed that 81% (35/43) of the neurons had excitatory responses to both intrapericardial BK and CAP, and the remainder responded to either BK or CAP. Intrapericardial resiniferatoxin (RTX) (0.2 μg/ml, 0.2 ml, 1 min), which desensitizes TRPV1-containing nerve endings, abolished excitatory responses to both BK ( n = 8) and CAP ( n = 7), and to AC ( n = 5) but not to somatic stimuli. Intrapericardial capsazepine (1 mg/ml, 0.2 ml, 3 min), a specific antagonist of TRPV1, sharply attenuated excitatory responses to CAP in 5/5 neurons, but responses to BK in 5/5 neurons was maintained. Additionally, intrapericardial capsazepine had no significant effect on excitatory responses to AC in 3/3 neurons. These data indicated that intrapericardial BK-initiated spinal neuronal responses were linked to cardiac TRPV1-containing afferent fibers, but were not dependent on TRPV1. Intraspinal signaling for cardiac nociception was mediated through CAP-sensitive afferent fibers innervating the heart.

Beyond trauma-focused psychiatric epidemiology: bridging research and practice with war-affected populations

This article examines the centrality of trauma-focused psychiatric epidemiology (TFPE) in research with war-affected populations. The authors question the utility of the dominant focus on posttraumatic stress disorder and other disorders of Western psychiatry, and they identify a set of critical research foci related to mental health work with communities affected by political violence. Core assumptions of TFPE and its roots in logical positivism and the biomedical model of contemporary psychiatry are explored. The authors suggest that an alternative framework--social constructivism--can serve as a bridge between researchers and practitioners by helping to refocus research efforts in ways that are conceptually and methodologically more attuned to the needs of war-affected communities and those working to address their mental health needs.

The Afghan symptom checklist: a culturally grounded approach to mental health assessment in a conflict zone

This article describes a methodology for developing culturally grounded assessment measures in conflict and postconflict situations. A mixed-method design was used in Kabul, Afghanistan, to identify local indicators of distress and develop the 22-item Afghan Symptom Checklist (ASCL). The ASCL contains several indigenous items and items familiar to Western mental health professionals. The ASCL was pilot tested and subsequently administered to 324 adults in 8 districts of Kabul. It demonstrated excellent reliability (alpha=.93) and good construct validity, correlating strongly with a measure of exposure to war-related violence and loss (r=.70). Results of the survey indicate moderate levels of distress among Afghan men and markedly higher levels of distress and impaired functioning among women (and widows in particular).

Relation between intrinsic connections and isofrequency contours in the inferior colliculus of the big brown bat, Eptesicus fuscus

Information processing in the inferior colliculus depends on interactions between ascending pathways and intrinsic circuitry, both of which exist within a functional tonotopic organization. To determine how local projections of neurons in the inferior colliculus are related to tonotopy, we placed a small iontophoretic injection of biodextran amine at a physiologically characterized location in the inferior colliculus. We then used electrophysiological recording to place a grid of small deposits of Chicago Sky Blue throughout the same frequency range to specify an isofrequency contour. Using three-dimensional computer reconstructions, we analyzed patterns of transport relative to the physiologically determined isofrequency contour to quantify the extent of the intrinsic connection lamina in all three dimensions. We also performed a quantitative analysis of the numbers of cells in different regions relative to the biodextran amine injection. Biodextran amine-labeled fibers were mainly located dorsomedial to the injection site, confined within the isofrequency contour, but biodextran amine-labeled cells were mainly located ventrolateral to the injection site. When we counted numbers of labeled cells classified by morphological type, we found that both elongate and multipolar cells were labeled within the isofrequency contour. Because the dendrites of multipolar cells typically extend outside the isofrequency lamina, it is likely that they receive input from other isofrequency contours and relay it to more dorsomedial portions of their specific isofrequency contour, along with the frequency-specific projections of the elongate cells. Within a given isofrequency contour, there is a consistent organization in which intrinsic connections ascend from the ventrolateral portion to more dorsomedial points along the contour, forming a cascaded system of intrinsic feedforward connections that seem ideally suited to provide the delay lines necessary to produce several forms of selectivity for temporal patterns in inferior colliculus neurons.

Observations of improved stability and confinement in a high-beta self-organized spherical-torus-like field-reversed configuration

An extremely high-beta (over 85%) self-organized field-reversed configuration (FRC) with a spherical-torus- (ST-)like core is produced in the translation, confinement, and sustainment experiment by highly super-Alfvénic translation of a spheromaklike plasmoid. Substantial flux conversion from toroidal into poloidal occurs during the capture process, resulting in the ST-like core. This plasma state exhibits a remarkable stabilizing property for the ubiquitous centrifugally driven interchange modes present in theta-pinch formed FRCs. This is explained, for the first time, by a simple model taking into account magnetic shear and centrifugal effects. The FRC-ST configuration has up to 4 times improvement in flux confinement times over the scaling of conventional theta-pinch formed FRCs and, thus, a significant improvement in the resistivity and transport.

The effect of insulin deficiency on tau and neurofilament in the insulin knockout mouse

Complications of diabetes mellitus within the nervous system are peripheral and central neuropathy. In peripheral neuropathy, defects in neurofilament and microtubules have been demonstrated. In this study, we examined the effects of insulin deficiency within the brain in insulin knockout mice (I-/-). The I-/- exhibited hyperphosphorylation of tau, at threonine 231, and neurofilament. In addition, we showed hyperphosphorylation of c-Jun N-terminal kinase (JNK) and glycogen synthase kinase 3 beta (GSK-3 beta) at serine 9. Extracellular signal-regulated kinase 1 (ERK 1) showed decrease in phosphorylation, whereas ERK 2 showed no changes. Ultrastructural examination demonstrated swollen mitochondria, endoplasmic reticulum, and Golgi apparatus, and dispersion of the nuclear chromatin. Microtubules showed decrease in the number of intermicrotubule bridges and neurofilament presented as bunches. Thus, lack of insulin brain stimulation induces JNK hyperphosphorylation followed by hyperphosphorylation of tau and neurofilament, and ultrastructural cellular damage, that over time may induce decrease in cognition and learning disabilities.