Exercise Enhances the Behavioral Responses to Acute Stress in an Animal Model of PTSD

The Psychological Impact of Exposure to Battle on Medics: A Cross-Sectional Study of Ex-Soldiers Who Sought Help From the IDF Combat Reaction Unit

INTRODUCTION

The present study's central aim was to examine two questions: (1) Will there be differences in mental health outcomes between medics and non-medics who sought help at the Israeli Combat Reaction Unit (CRU)? (2) Will there be differences in mental health outcomes between combatants and non-combatants?

MATERIALS AND METHODS

This cross-sectional study included files of 1,474 Israeli Defense Forces ex-service members (89% combatants, of whom 13% were medics; 11% non-combatants, of whom 6% were medics), who filled out questionnaires on admission for evaluation at the CRU.Dependent variables were mental health measures and included two PTSD measures (Clinician-Administered PTSD Scale and PTSD Checklist for DSM-5), Beck Depression Inventory, Dissociative Experience Scale, and Brief Symptom Inventory. Military profession (medics vs. non-medics) and status (combatant vs. non-combatant) were the independent variables. Background variables were also examined.

RESULTS

We found no substantial differences between medics and non-medics in the mental health measures. When looking at combat and non-combat separately, the non-combat medics (CMs), in general, were in better mental health conditions than the other three groups- CMs, non-medic combatants, and non-medic non-combatants-all of whom had similar scores in the mental health measures. However, compared to the rest, non-CMs took considerably longer years before approaching the CRU.

CONCLUSIONS

The elapsed time to seek help for non-MCs was explained by their reluctance to seek help, not being combatants, and being medics who are portrayed as resilient. Recommendations for encouraging this subgroup to seek help were given.

Adulthood effects of developmental exercise in rats

Exercise is known to promote efficient function of stress circuitry. The developing brain is malleable and thus exercise during adolescence could potentially exert lasting beneficial effects on the stress response that would be detectable in adulthood. The current study determined whether adolescent wheel running was associated with reduced stress response in adulthood, 6 weeks after cessation of exercise. Male and female adolescent rats voluntarily ran for 6 weeks and then were sedentary for 6 weeks prior to 10 days of chronic restraint stress in adulthood. Fecal corticosterone levels were measured during stress, and escape from the restraint tube was assessed on the final day as a proxy for depressive-like behavior. Anxiety-like behavior was measured 24 h later with the elevated plus maze and locomotor behaviors with the open field. Brain and body measurements were taken immediately following behavioral testing. Developmental exercise and adulthood stress both exerted independent effects on physiological and behavioral outcomes in adulthood. Exercise history increased the odds ratio of escape from restraint stress in males, but did not influence other stress-induced behaviors. In summary, exercise early in life exerted lasting effects, but did not substantially alter the adulthood response to restraint stress.

Running from Stress: Neurobiological Mechanisms of Exercise-Induced Stress Resilience

Chronic stress, even stress of a moderate intensity related to daily life, is widely acknowledged to be a predisposing or precipitating factor in neuropsychiatric diseases. There is a clear relationship between disturbances induced by stressful stimuli, especially long-lasting stimuli, and cognitive deficits in rodent models of affective disorders. Regular physical activity has a positive effect on the central nervous system (CNS) functions, contributes to an improvement in mood and of cognitive abilities (including memory and learning), and is correlated with an increase in the expression of the neurotrophic factors and markers of synaptic plasticity as well as a reduction in the inflammatory factors. Studies published so far show that the energy challenge caused by physical exercise can affect the CNS by improving cellular bioenergetics, stimulating the processes responsible for the removal of damaged organelles and molecules, and attenuating inflammation processes. Regular physical activity brings another important benefit: increased stress robustness. The evidence from animal studies is that a sedentary lifestyle is associated with stress vulnerability, whereas a physically active lifestyle is associated with stress resilience. Here, we have performed a comprehensive PubMed Search Strategy for accomplishing an exhaustive literature review. In this review, we discuss the findings from experimental studies on the molecular and neurobiological mechanisms underlying the impact of exercise on brain resilience. A thorough understanding of the mechanisms underlying the neuroprotective potential of preconditioning exercise and of the role of exercise in stress resilience, among other things, may open further options for prevention and therapy in the treatment of CNS diseases.

A salience hypothesis of stress in PTSD

Attention to key features of contexts and things is a necessary tool for all organisms. Detecting these salient features of cues, or simply, salience, can also be affected by exposure to traumatic stress, as has been widely reported in individuals suffering from post-traumatic stress disorder (PTSD). Interestingly, similar observations have been robustly replicated across many animal models of stress as well. By using evidence from such rodent stress paradigms, in the present review, we explore PTSD through the lens of salience processing. In this context, we propose that interaction between the neurotrophin brain-derived neurotrophic factor (BDNF) and glucocorticoids determines the long lasting cellular and behavioural consequences of stress salience. We also describe the dual effect of glucocorticoid therapy in the amelioration of PTSD symptoms. Finally, by integrating in vivo observations at multiple scales of plasticity, we propose a unifying hypothesis that pivots on a crucial role of glucocorticoid signalling in dynamically orchestrating stress salience.

β-Alanine Supplementation Attenuates the Neurophysiological Response in Animals Exposed to an Acute Heat Stress

The effect of 30 days of β-alanine supplementation on neurophysiological responses of animals exposed to an acute heat stress (HS) was examined. Animals were randomized to one of three groups; exposed to HS (120 min at 40-41 °C) and fed a normal diet (EXP; n = 12); EXP and supplemented with β-alanine (EXP + BA; n = 10); or not exposed (CTL; n = 10). Hippocampal (CA1, CA3 and DG) and hypothalamic (PVN) immunoreactive (ir) cell numbers of COX2, IBA-1, BDNF, NPY and HSP70 were analyzed. Three animals in EXP and one in EXP-BA did not survive the HS, however no significant difference (p = 0.146) was noted in survival rate in EXP + BA. The % change in rectal temperature was significantly lower (p = 0.04) in EXP + BA than EXP. Elevations (p's < 0.05) in COX-2, IBA-1 and HSP70 ir-cell numbers were noted in animals exposed to HS in all subregions. COX-2 ir-cell numbers were attenuated for EXP + BA in CA1 (p = 0.02) and PVN (p = 0.015) compared to EXP. No difference in COX-2 ir-cell numbers was noted between CTL and EXP + BA at CA1. BDNF-ir cell numbers in CA1, DG and PVN were reduced (p's < 0.05) during HS compared to CTL. No difference in BDNF-ir cell numbers was noted between EXP + BA and CTL in CA3 and PVN. NPY-ir density was reduced in exposed animals in all subregions, but NPY-ir density for EXP-BA was greater than EXP in CA3 (p < 0.001) and PVN (p = 0.04). β-Alanine supplementation attenuated the thermoregulatory and inflammatory responses and maintained neurotrophin and neuropeptide levels during acute HS. Further research is necessary to determine whether β-alanine supplementation can increase survival rate during a heat stress.

Antidepressants Promote and Prevent Cancers

The review states that antidepressants (ADs) increase brain-derived neurotrophic factor (BDNF) transmission concomitantly in the brain and the blood: ADs increasing BDNF synthesis in specific areas of the central nervous system (CNS) could presumably affect megakaryocyte's production of platelets. ADs increase BDNF levels in the CNS and improve mood. In the blood, ADs increase BDNF release from platelets. The hypothesis presented here is that the release of BDNF from platelets contributes to the ADs effects on neurogenesis and on tumor growth in the cancer disease. Oncological studies indicate that chemicals ADs exert an aggravating effect on the cancer disease, possibly by promoting proplatelets formation and enhancing BDNF release from platelets in the tumor.

Chronic harmine treatment has a delayed effect on mobility in control and socially defeated rats

INTRODUCTION

Depression is characterized by behavioral, cognitive and physiological changes, imposing a major burden on the overall wellbeing of the patient. Some evidence indicates that social stress, changes in growth factors (e.g., brain-derived neurotrophic factor (BDNF)), and neuroinflammation are involved in the development and progression of the disease. The monoamine oxidase A inhibitor drug harmine was suggested to have both antidepressant and anti-inflammatory properties and may, therefore, be a potential candidate for treatment of depression.

AIM

The goal of this study was to assess the effects of harmine on behavior, brain BDNF levels, and microglia activation in control rats and a rat model of social stress.

MATERIAL AND METHODS

Rats were submitted to 5 consecutive days of repeated social defeat (RSD) or control conditions. Animals were treated daily with harmine (15 mg/kg) or vehicle from day 3 until the end of the experiment. To assess the effects of harmine treatment on behavior, the sucrose preference test (SPT) was performed on days 1, 6, and 15, the open field test (OFT) on days 6 and 14, and the novel object recognition test (NOR) on day 16. Brain microgliosis was assessed using [11C]PBR-28 PET on day 17. Animals were terminated on day 17, and BDNF protein concentrations in the hippocampus and frontal cortex were analyzed using ELISA.

RESULTS

RSD significantly decreased bodyweight and increased anxiety and anhedonia-related parameters in the OFT and SPT on day 6, but these behavioral effects were not observed anymore on day 14/15. Harmine treatment caused a significant reduction in bodyweight gain in both groups, induced anhedonia in the SPT on day 6, and significantly reduced the mobility and exploratory behavior of the animals in the OFT mainly on day 14. PET imaging and the NOR test did not show any significant effects on microglia activation and memory, respectively. BDNF protein concentrations in the hippocampus and frontal cortex were not significantly affected by either RSD or harmine treatment.

DISCUSSION

Harmine was not able to reverse the acute effects of RSD on anxiety and anhedonia and even aggravated the effect of RSD on bodyweight loss. Moreover, harmine treatment caused unexpected side effects on general locomotion, both in RSD and control animals, but did not influence glial activation status and BDNF concentrations in the brain. In this model, RSD-induced stress was not strong enough to induce long-term effects on the behavior, neuroinflammation, or BDNF protein concentration. Thus, the efficacy of harmine treatment on these delayed parameters needs to be further evaluated in more severe models of chronic stress.

A probabilistic model of startle response reveals opposite effects of acute versus chronic Methylphenidate treatment

BACKGROUND

The startle response is considered as the major physio-behavioral indication of anxiety in health and disease conditions. However, due to different protocols of stimulation and measurement, the magnitude as well as the appearance of the startle response is inconsistent.

NEW METHOD

We postulate that the startle probability and not merely the amplitude may bare information that will form a consistent physiological measure of anxiety.

RESULTS

To examine the proof-of-concept of our suggested probability model, we evaluated the effects of acute (single) versus chronic (14 days) MPH administration on both startle amplitude and probability. We found that both acute and chronic MPH administration has yielded similar effects on startle amplitude. However, acute MPH increased the startle's probability while chronic MPH decreased it. Next, we evaluated the effects of acute versus chronic stress on the startle's parameters and found a complementary effect. Explicitly, acute stress increased the startle's probability while chronic stress increased the startle amplitude. In contrast, enriched environment had no significant effects. Finally, to further validate the probability measure, we show that Midazolam had significant anxiolytic effects. In the second part, we investigated the acoustic startle response parameters (e.g. background noise and pulse duration), to better understand the interplay between these parameters and the startle amplitude versus probability.

CONCLUSIONS

We show that the probabilistic element of the startle response does not only point to deeper physiologic relationships but may also serve as "hidden variables" congruent but not entirely identical to the commonly researched amplitude of the startle response.

Association between circulating inflammatory markers and marksmanship following intense military training

Introduction

Intense military operations during deployment or training are associated with elevations in inflammatory cytokine markers. However, the influence of an inflammatory response on military-specific skills is unclear. This study examined the association between brain-derived neurotrophic factor (BDNF), glial fibrillar acidic protein, markers of inflammation, marksmanship and cognitive function following a week of intense military field training.

Methods

Twenty male soldiers (20.1±0.6 years; 1.78±0.05m; 74.1±7.9kg) from the same elite combat unit of the Israel Defense Forces volunteered to participate in this study. Soldiers completed a five-day period of intense field training including navigation of 27.8km/day with load carriages of ~50% of their body mass. Soldiers slept approximately fivehours per day and were provided with military field rations. Following the final navigational exercise, soldiers returned to their base and provided a blood sample. In addition, cognitive function assessment and both dynamic and static shooting (15 shots each) were performed following a 200 m gauntlet, in which soldiers had to use hand-to-hand combat skills to reach the shooting range.

Results

Results revealed that tumour necrosis factor-α (TNF-α) concentrations were inversely correlated with dynamic shooting (r=−0.646, p=0.005). In addition, a trend (r=0.415, p=0.098) was noted between TNF-α concentrations and target engagement speed (ie, time to complete the shooting protocol). BDNF concentrations were significantly correlated with the Serial Sevens Test performance (r=0.672, p=0.012).

Conclusion

The results of this investigation indicate that elevated TNF-α concentrations and lower BDNF concentrations in soldiers following intense military training were associated with decreases in marksmanship and cognitive function, respectively.

Brain-Derived Neurotrophic Factor in Brain Disorders: Focus on Neuroinflammation

Brain-derived neurotrophic factor (BDNF) is one of the most studied neurotrophins in the healthy and diseased brain. As a result, there is a large body of evidence that associates BDNF with neuronal maintenance, neuronal survival, plasticity, and neurotransmitter regulation. Patients with psychiatric and neurodegenerative disorders often have reduced BDNF concentrations in their blood and brain. A current hypothesis suggests that these abnormal BDNF levels might be due to the chronic inflammatory state of the brain in certain disorders, as neuroinflammation is known to affect several BDNF-related signaling pathways. Activation of glia cells can induce an increase in the levels of pro- and antiinflammatory cytokines and reactive oxygen species, which can lead to the modulation of neuronal function and neurotoxicity observed in several brain pathologies. Understanding how neuroinflammation is involved in disorders of the brain, especially in the disease onset and progression, can be crucial for the development of new strategies of treatment. Despite the increasing evidence for the involvement of BDNF and neuroinflammation in brain disorders, there is scarce evidence that addresses the interaction between the neurotrophin and neuroinflammation in psychiatric and neurodegenerative diseases. This review focuses on the effect of acute and chronic inflammation on BDNF levels in the most common psychiatric and neurodegenerative disorders and aims to shed some light on the possible biological mechanisms that may influence this effect. In addition, this review will address the effect of behavior and pharmacological interventions on BDNF levels in these disorders.

On the Run for Hippocampal Plasticity

Accumulating research in rodents and humans indicates that exercise benefits brain function and may prevent or delay onset of neurodegenerative conditions. In particular, exercise modifies the structure and function of the hippocampus, a brain area important for learning and memory. This review addresses the central and peripheral mechanisms underlying the beneficial effects of exercise on the hippocampus. We focus on running-induced changes in adult hippocampal neurogenesis, neural circuitry, neurotrophins, synaptic plasticity, neurotransmitters, and vasculature. The role of peripheral factors in hippocampal plasticity is also highlighted. We discuss recent evidence that systemic factors released from peripheral organs such as muscle (myokines), liver (hepatokines), and adipose tissue (adipokines) during exercise contribute to hippocampal neurotrophin and neurogenesis levels, and memory function. A comprehensive understanding of the body-brain axis is needed to elucidate how exercise improves hippocampal plasticity and cognition.

Resveratrol ameliorated the behavioral deficits in a mouse model of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) has become a major psychiatric and neurological issue. Resveratrol is shown to be effective on depression and anxiety. However, the mechanism of anti-PTSD-like effects of resveratrol remains unknown. The present study aimed to explore the possible molecular and cellular mechanisms underlying the anti-PTSD-like effects of resveratrol. Following a 2-day exposure to inescapable electric foot shocks, animals were administered resveratrol (10, 20, and 40mg/kg, i.g.) during the behavioral tests, which included contextual freezing measurement, elevated plus maze test, staircase test, and open field test. Similar to the positive control drug sertraline (15mg/kg, i.g.), the behavioral deficits of stressed mice were blocked by resveratrol (20 and 40mg/kg, i.g.), which reversed the increased freezing time in contextual freezing measurement and the number of rears in the staircase test and blocked the decrease in time and number of entries in open arms in the elevated plus maze test without affecting the locomotor activity in the open field test. In addition, resveratrol (20 and 40mg/kg, i.g.) antagonized the decrease in the levels of progesterone and allopregnanolone in the prefrontal cortex and hippocampus. Furthermore, long-term resveratrol attenuated the dysfunctions of hypothalamic-pituitary-adrenal axis simultaneously. Collectively, the evidence indicated that the anti-PTSD-like effects of resveratrol were associated with the normalization of biosynthesis of neurosteroids in the brain and prevention of the hypothalamic-pituitary-adrenal axis dysfunction.

Endogenously Released Neuropeptide Y Suppresses Hippocampal Short-Term Facilitation and Is Impaired by Stress-Induced Anxiety

Neuropeptide Y (NPY) has robust anxiolytic properties and is reduced in patients with anxiety disorders. However, the mechanisms by which NPY modulates circuit function to reduce anxiety behavior are not known. Anxiolytic effects of NPY are mediated in the CA1 region of hippocampus, and NPY injection into hippocampus alleviates anxiety symptoms in the predator scent stress model of stress-induced anxiety. The mechanisms that regulate NPY release, and its effects on CA1 synaptic function, are not fully understood. Here we show in acute hippocampal slices from mice that endogenous NPY, released in response to optogenetic stimulation or synaptically evoked spiking of NPY+ cells, suppresses both of the feedforward pathways to CA1. Stimulation of temporoammonic synapses with a physiologically derived spike train causes NPY release that reduces short-term facilitation, whereas the release of NPY that modulates Schaffer collateral synapses requires integration of both the Schaffer collateral and temporoammonic pathways. Pathway specificity of NPY release is conferred by three functionally distinct NPY+ cell types, with differences in intrinsic excitability and short-term plasticity of their inputs. Predator scent stress abolishes the release of endogenous NPY onto temporoammonic synapses, a stress-sensitive pathway, thereby causing enhanced short-term facilitation. Our results demonstrate how stress alters CA1 circuit function through the impairment of endogenous NPY release, potentially contributing to heightened anxiety.

SIGNIFICANCE STATEMENT

Neuropeptide Y (NPY) has robust anxiolytic properties, and its levels are reduced in patients with post-traumatic stress disorder. The effects of endogenously released NPY during physiologically relevant stimulation, and the impact of stress-induced reductions in NPY on circuit function, are unknown. By demonstrating that NPY release modulates hippocampal synaptic plasticity and is impaired by predator scent stress, our results provide a novel mechanism by which stress-induced anxiety alters circuit function. These studies fill an important gap in knowledge between the molecular and behavioral effects of NPY. This article also advances the understanding of NPY+ cells and the factors that regulate their spiking, which could pave the way for new therapeutic targets to increase endogenous NPY release in patients in a spatially and temporally appropriate manner.

Behavioral and inflammatory response in animals exposed to a low-pressure blast wave and supplemented with β-alanine

This study investigated the benefit of β-alanine (BA) supplementation on behavioral and cognitive responses relating to mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) in rats exposed to a low-pressure blast wave. Animals were fed a normal diet with or without (PL) BA supplementation (100 mg kg⁻¹) for 30-day, prior to being exposed to a low-pressure blast wave. A third group of animals served as a control (CTL). These animals were fed a normal diet, but were not exposed to the blast. Validated cognitive-behavioral paradigms were used to assess both mTBI and PTSD-like behavior on days 7–14 following the blast. Brain-derived neurotrophic factor (BDNF), neuropeptide Y, glial fibrillary acidic protein (GFAP) and tau protein expressions were analyzed a day later. In addition, brain carnosine and histidine content was assessed as well. The prevalence of animals exhibiting mTBI-like behavior was significantly lower (p = 0.044) in BA than PL (26.5 and 46%, respectively), but no difference (p = 0.930) was noted in PTSD-like behavior between the groups (10.2 and 12.0%, respectively). Carnosine content in the cerebral cortex was higher (p = 0.048) for BA compared to PL, while a trend towards a difference was seen in the hippocampus (p = 0.058) and amygdala (p = 0.061). BDNF expression in the CA1 subregion of PL was lower than BA (p = 0.009) and CTL (p < 0.001), while GFAP expression in CA1 (p = 0.003) and CA3 (p = 0.040) subregions were higher in PL than other groups. Results indicated that BA supplementation for 30-day increased resiliency to mTBI in animals exposed to a low-pressure blast wave.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Chronic occupational exposures can influence the rate of PTSD and depressive disorders in first responders and military personnel

BACKGROUND

First responders and military personnel experience rates of post-traumatic stress disorder (PTSD) far in excess of the general population. Although exposure to acute traumatic events plays a role in the genesis of these disorders, in this review, we present an argument that the occupational and environmental conditions where these workers operate are also likely contributors.

PRESENTATION OF THE HYPOTHESIS

First responders and military personnel face occupational exposures that have been associated with altered immune and inflammatory activity. In turn, these physiological responses are linked to altered moods and feelings of well-being which may provide priming conditions that compromise individual resilience, and increase the risk of PTSD and depression when subsequently exposed to acute traumatic events. These exposures include heat, smoke, and sleep restriction, and physical injury often alongside heavy physical exertion. Provided the stimulus is sufficient, these exposures have been linked to inflammatory activity and modification of the hypothalamic-pituitary axis (HPA), offering a mechanism for the high rates of PTSD and depressive disorders in these occupations.

TESTING THE HYPOTHESIS

To test this hypothesis in the future, a case-control approach is suggested that compares individuals with PTSD or depressive disorders with healthy colleagues in a retrospective framework. This approach should characterise the relationships between altered immune and inflammatory activity and health outcomes. Wearable technology, surveys, and formal experimentation in the field will add useful data to these investigations.

IMPLICATIONS OF THE HYPOTHESIS

Inflammatory changes, linked with occupational exposures in first responders and military personnel, would highlight the need for a risk management approach to work places. Risk management strategies could focus on reducing exposure, ensuring recovery, and increasing resilience to these risk contributors to minimise the rates of PTSD and depressive disorders in vulnerable occupations.

Short-term enriched environment exposure facilitates fear extinction in adult rats: The NPY-Y1 receptor modulation

Neuropeptides have an important role in several psychiatric conditions. Among them, neuropeptide Y (NPY) seems to be essential to modulate some features of stress-related disorders. Post-traumatic stress disorder (PTSD), characterized by inappropriate fear generalization to safe situations may be modulated by NPY manipulation since this neuropeptide is involved in the promotion of coping with stress. Experimentally, coping strategies have been obtained after exposure in enriched environment (EE) rather than standard one. Thus, in the present study we aimed to assess whether short-term EE situation and NPY-Y1 receptor (Y1r) modulation may affect the extinction of contextual fear conditioning, an experimental approach to PTSD. Here we show that EE-rats have the contextual fear extinction facilitated, and this facilitation was reverted by central infusion of BIBO3304, a nonpeptide Y1r antagonist. In addition, protein analysis revealed an upregulation of hippocampal Y1r in conditioned EE-rats, but no changes were observed in EE-rats that were not conditioned. Our results demonstrated that protective properties of EE on fear extinction can be regulated, at least in part, by activation of NPY-signaling through Y1r within hippocampus, an area that plays a major role in contextual memories. Overall, the activation of Y1r is important to promote better and faster perception of self-location (context), and to reduce fear generalization in rats exposed to EE.

Neuropeptide Y: A stressful review

Stress is defined as an adverse condition that disturbs the homeostasis of the body and activates adaptation responses. Among the many pathways and mediators involved, neuropeptide Y (NPY) stands out due to its unique stress-relieving, anxiolytic and neuroprotective properties. Stress exposure alters the biosynthesis of NPY in distinct brain regions, the magnitude and direction of this effect varying with the duration and type of stress. NPY is expressed in particular neurons of the brainstem, hypothalamus and limbic system, which explains why NPY has an impact on stress-related changes in emotional-affective behaviour and feeding as well as on stress coping. The biological actions of NPY in mammals are mediated by the Y1, Y2, Y4 and Y5 receptors, Y1 receptor stimulation being anxiolytic whereas Y2 receptor activation is anxiogenic. Emerging evidence attributes NPY a role in stress resilience, the ability to cope with stress. Thus there is a negative correlation between stress-induced behavioural disruption and cerebral NPY expression in animal models of post-traumatic stress disorder. Exogenous NPY prevents the negative consequences of stress, and polymorphisms of the NPY gene are predictive of impaired stress processing and increased risk of neuropsychiatric diseases. Stress is also a factor contributing to, and resulting from, neurodegenerative diseases such as Alzheimer's, Parkinson's and Huntington's disease, in which NPY appears to play an important neuroprotective role. This review summarizes the evidence for an implication of NPY in stress-related and neurodegenerative pathologies and addresses the cerebral NPY system as a therapeutic target.

Early life adversity and/or posttraumatic stress disorder severity are associated with poor diet quality, including consumption of trans fatty acids, and fewer hours of resting or sleeping in a US middle-aged population: A cross-sectional and prospective study

BACKGROUND

Early life adversity (ELA) and post-traumatic stress disorder (PTSD) are associated with poorer psychological and physical health. Potential underlying mechanisms and mediators remain to be elucidated, and the lifestyle habits and characteristics of individuals with ELA and/or PTSD have not been fully explored. We investigated whether the presence of ELA and/or PTSD are associated with nutrition, physical activity, resting and sleeping and smoking.

METHODS

A cross-sectional sample of 151 males and females (age: 45.6±3.5 years, BMI: 30.0±7.1 kg/m(2)) underwent anthropometric measurements, as well as detailed questionnaires for dietary assessment, physical activity, resting and sleeping, smoking habits and psychosocial assessments. A prospective follow-up visit of 49 individuals was performed 2.5 years later and the same outcomes were assessed. ELA and PTSD were evaluated as predictors, in addition to a variable assessing the combined presence/severity of ELA-PTSD. Data were analyzed using analysis of covariance after adjusting for several socioeconomic, psychosocial and anthropometric characteristics.

RESULTS

Individuals with higher ELA or PTSD severity were found to have a poorer diet quality (DASH score: p=0.006 and p=0.003, respectively; aHEI-2010 score: ELA p=0.009), including further consumption of trans fatty acids (ELA p=0.003); the differences were significantly attenuated null after adjusting mainly for education or income and/or race. Further, individuals with higher ELA severity reported less hours of resting and sleeping (p=0.043) compared to those with zero/lower ELA severity, and the difference remained significant in the fully adjusted model indicating independence from potential confounders. When ELA and PTSD were combined, an additive effect was observed on resting and sleeping (p=0.001); results remained significant in the fully adjusted model. They also consumed more energy from trans fatty acids (p=0.017) tended to smoke more (p=0.008), and have less physical activity (PTSD p=0.024) compared to those with no or lower ELA and PTSD severity. Adjustments for sociodemographic factors and/or BMI rendered results of the above lifestyle parameters non-significant. The analysis of the prospective data showed similar trends to the cross-sectional analysis, further supporting the conclusions, although statistical significance of results was lower due to the lower number of participants.

CONCLUSION

Fewer hours of resting and sleeping and poorer diet quality are linked to ELA and/or PTSD, indicating that these pathways might underlie the development of several metabolic abnormalities in individuals with ELA and/or PTSD. Differences in terms of diet quality are significantly attenuated by race and/or education and/or income, whereas differences in other lifestyle habits of individuals with and without ELA and/or PTSD, such as physical activity, are mostly explained by confounding sociodemographic variables and/or body mass index.