Serum amyloid A-dependent inflammasome activation and acute injury in a mouse model of experimental stroke

Serum amyloid A (SAA) proteins increase dramatically in the blood following inflammation. Recently, SAAs are increased in humans following stroke and in ischemic animal models. However, the impact of SAAs on whether this signal is critical in the ischemic brain remains unknown. Therefore, we investigated the role of SAA and SAA signaling in the ischemic brain. Wildtype and SAA deficient mice were exposed to middle cerebral artery occlusion and reperfusion, examined for the impact of infarct volumes, behavioral changes, inflammatory markers, TUNEL staining, and BBB changes. The underlying mechanisms were investigated using SAA deficient mice, transgenic mice and viral vectors. SAA levels were significantly increase following MCAo and mice deficient in SAAs showed reduced infarct volumes and improved behavioral outcomes. SAA deficient mice showed a reduction in TUNEL staining, inflammation and decreased glial activation. Mice lacking acute phase SAAs demonstrated a reduction in expression of the NLRP3 inflammasome and SAA/NLRP3 KO mice showed improvement. Restoration of SAA expression via SAA tg mice or adenoviral expression reestablished the detrimental effects of SAA. A reduction in BBB permeability was seen in the SAA KO mice and anti-SAA antibody treatment reduced the effects on ischemic injury. SAA signaling plays a critical role in regulating NLRP3-induced inflammation and glial activation in the ischemic brain. Blocking this signal will be a promising approach for treating ischemic stroke.

Historical Review of the Use of Relative Risk Statistics in the Portrayal of the Purported Hazards of High LDL Cholesterol and the Benefits of Lipid-Lowering Therapy

The manner in which clinical trial investigators present their findings to healthcare providers and the public can have a substantial influence on their impact. For example, if a heart attack occurs in 2% of those in the placebo group and in 1% of those in the drug-treated group, the benefit to the treated population is only one percentage point better than no treatment. This finding is unlikely to generate much enthusiasm from the study sponsors and in the reporting of the findings to the public. Instead, trial directors can amplify the magnitude of the appearance of the treatment benefit by using the relative risk (RR) value of a 50% reduction of the risk of a heart attack, since one is 50% of two. By using the RR type of data analysis, clinical trial directors can promote the outcome of their trial in their publication and to the media as highly successful while minimizing or disregarding entirely the absolute risk (AR) reduction of only one percentage point. The practice of expressing the RR without the AR has become routinely deployed in the reporting of findings in many different areas of clinical research. We have provided a historical perspective on how this form of data presentation has become commonplace in the reporting of findings from randomized controlled trials (RCTs) on coronary heart disease (CHD) event monitoring and prevention over the past four decades. We assert that the emphasis on RR coupled with insufficient disclosure of AR in the reporting of RCT outcomes has led healthcare providers and the public to overestimate concerns about high cholesterol and to be misled as to the magnitude of the benefits of cholesterol-lowering therapy. The goal of this review is to prompt the scientific community to address this misleading approach to data presentation.

Correction: Historical Review of the Use of Relative Risk Statistics in the Portrayal of the Purported Hazards of High LDL Cholesterol and the Benefits of Lipid-Lowering Therapy

[This corrects the article DOI: 10.7759/cureus.38391.].

Statin therapy is not warranted for a person with high LDL-cholesterol on a low-carbohydrate diet

PURPOSE OF REVIEW

Although there is an extensive literature on the efficacy of the low carbohydrate diet (LCD) for weight loss and in the management of type 2 diabetes, concerns have been raised that the LCD may increase cardiovascular disease (CVD) risk by increasing the level of low-density lipoprotein cholesterol (LDL-C). We have assessed the value of LDL-C as a CVD risk factor, as well as effects of the LCD on other CVD risk factors. We have also reviewed findings that provide guidance as to whether statin therapy would be beneficial for individuals with high LDL-C on an LCD.

RECENT FINDINGS

Multiple longitudinal trials have demonstrated the safety and effectiveness of the LCD, while also providing evidence of improvements in the most reliable CVD risk factors. Recent findings have also confirmed how ineffective LDL-C is in predicting CVD risk.

SUMMARY

Extensive research has demonstrated the efficacy of the LCD to improve the most robust CVD risk factors, such as hyperglycemia, hypertension, and atherogenic dyslipidemia. Our review of the literature indicates that statin therapy for both primary and secondary prevention of CVD is not warranted for individuals on an LCD with elevated LDL-C who have achieved a low triglyceride/HDL ratio.

Control of β-Site Amyloid Precursor Protein-Cleaving Enzyme-1 Expression by Protein Kinase C-λ/ι and Nuclear Factor κ-B

Βackground: β-Amyloid precursor protein-cleaving enzyme-1 (BACE1) initiates the production of Aβ-peptides that form Aβ-plaque in Alzheimer's disease.

METHODS

Reportedly, acute insulin treatment in normal mice, and hyperinsulinemia in high-fat-fed (HFF) obese/diabetic mice, increase BACE1 activity and levels of Aβ-peptides and phospho- -thr-231-tau in the brain; moreover, these effects are blocked by PKC-λ/ι inhibitors. However, as chemical inhibitors may affect unsuspected targets, we presently used knockout methodology to further examine PKC-λ/ι requirements. We found that total-body heterozygous PKC-λ knockout reduced acute stimulatory effects of insulin and chronic effects of hyperinsulinemia in HFF/obese/diabetic mice, on brain PKC-λ activity and production of Aβ1-40/42 and phospho-thr-231-tau. This protection in HFF mice may reflect that hepatic PKC-λ haploinsufficiency prevents the development of glucose intolerance and hyperinsulinemia.

RESULTS

On the other hand, heterozygous knockout of PKC-λ markedly reduced brain levels of BACE1 protein and mRNA, and this may reflect diminished activation of nuclear factor kappa-B (NFκB), which is activated by PKC-λ and increases BACE1 and proinflammatory cytokine transcription. Accordingly, whereas intravenous administration of aPKC inhibitor diminished aPKC activity and BACE1 levels by 50% in the brain and 90% in the liver, nasally-administered inhibitor reduced aPKC activity and BACE1 mRNA and protein levels by 50-70% in the brain while sparing the liver. Additionally, 24-hour insulin treatment in cultured human-derived neurons increased NFκB activity and BACE1 levels, and these effects were blocked by various PKC-λ/ι inhibitors.

CONCLUSION

PKC-λ/ι controls NFκB activity and BACE1 expression; PKC-λ/ι inhibitors may be used nasally to target brain PKC-λ/ι or systemically to block both liver and brain PKC-λ/ι, to regulate NFκB-dependent BACE1 and proinflammatory cytokine expression.

Dietary Recommendations for Familial Hypercholesterolaemia: an Evidence-Free Zone

We have evaluated dietary recommendations for people diagnosed with familial hypercholesterolaemia (FH), a genetic condition in which increased low-density lipoprotein cholesterol (LDL-C) is associated with an increased risk for coronary heart disease (CHD). Recommendations for FH individuals have emphasised a low saturated fat, low cholesterol diet to reduce their LDL-C levels. The basis of this recommendation is the 'diet-heart hypothesis', which postulates that consumption of food rich in saturated fat increases serum cholesterol levels, which increases risk of CHD. We have challenged the rationale for FH dietary recommendations based on the absence of support for the diet-heart hypothesis, and the lack of evidence that a low saturated fat, low cholesterol diet reduces coronary events in FH individuals. As an alternative approach, we have summarised research which has shown that the subset of FH individuals that develop CHD exhibit risk factors associated with an insulin-resistant phenotype (elevated triglycerides, blood glucose, haemoglobin A1c (HbA1c), obesity, hyperinsulinaemia, high-sensitivity C reactive protein, hypertension) or increased susceptibility to develop coagulopathy. The insulin-resistant phenotype, also referred to as the metabolic syndrome, manifests as carbohydrate intolerance, which is most effectively managed by a low carbohydrate diet (LCD). Therefore, we propose that FH individuals with signs of insulin resistance should be made aware of the benefits of an LCD. Our assessment of the literature provides the rationale for clinical trials to be conducted to determine if an LCD would prove to be effective in reducing the incidence of coronary events in FH individuals which exhibit an insulin-resistant phenotype or hypercoagulation risk.

Serious flaws in targeting LDL-C reduction in the management of cardiovascular disease in familial hypercholesterolemia

Recently, Polychronopoulos and Tziomalos reviewed research on the use of inclisiran and bempedoic acid in the management of cardiovascular disease (CVD) risk in people with familial hypercholesterolemia (FH). Their treatment recommendations were based on the general premise that high LDL-cholesterol (LDL-C) is inherently atherogenic, and that low levels of LDL-C need to be achieved to reduce CVD risk in FH individuals. However, their perspective on LDL-C is flawed at two levels of analysis: 1) They ignored the extensive literature demonstrating that CVD is not caused by high LDL-C; and 2) they failed to consider CVD treatment strategies that take into account the extensive literature that has shown that coagulation factors are more closely related to coronary events in FH than is LDL-C. In the following, we have briefly addressed each of these flaws in their review.

The new European guidelines for prevention of cardiovascular disease are misleading

Introduction: The European Society of Cardiology and European Atherosclerosis Society (ESC/EAS) have recently published three major revisions of their guidelines for the management of chronic heart disease, blood lipids, and diabetes. Areas covered: We have scrutinized these guidelines in detail and found that the authors have ignored many studies that are in conflict with their conclusions and recommendations. Expert commentary: The authors of the guidelines have ignored that LDL-cholesterol (LDL-C) of patients with acute myocardial infarction is lower than normal; that high cholesterol is not a risk factor for diabetics; that the degree of coronary artery calcification is not associated with LDL-C; and that 27 follow-up studies have shown that people with high total cholesterol or LDL-C live just as long or longer than people with low cholesterol. They have also ignored the lack of exposure-response in the statin trials; that several of these trials have been unable to lower CVD or total mortality; that no statin trial has succeeded with lowering mortality in women, elderly people, or diabetics; and that cholesterol-lowering with statins has been associated with many serious side effects.

Low carbohydrate diet: are concerns with saturated fat, lipids, and cardiovascular disease risk justified?

PURPOSE OF REVIEW

There is an extensive literature on the efficacy of the low carbohydrate diet (LCD) for weight loss, and in the improvement of markers of the insulin-resistant phenotype, including a reduction in inflammation, atherogenic dyslipidemia, hypertension, and hyperglycemia. However, critics have expressed concerns that the LCD promotes unrestricted consumption of saturated fat, which may increase low-density lipoprotein (LDL-C) levels. In theory, the diet-induced increase in LDL-C increases the risk of cardiovascular disease (CVD). The present review provides an assessment of concerns with the LCD, which have focused almost entirely on LDL-C, a poor marker of CVD risk. We discuss how critics of the LCD have ignored the literature demonstrating that the LCD improves the most reliable CVD risk factors.

RECENT FINDINGS

Multiple longitudinal clinical trials in recent years have extended the duration of observations on the safety and effectiveness of the LCD to 2-3 years, and in one study on epileptics, for 10 years.

SUMMARY

The present review integrates a historical perspective on the LCD with a critical assessment of the persistent concerns that consumption of saturated fat, in the context of an LCD, will increase risk for CVD.

Exogenous Ketone Supplements Improved Motor Performance in Preclinical Rodent Models

Nutritional ketosis has been proven effective for neurometabolic conditions and disorders linked to metabolic dysregulation. While inducing nutritional ketosis, ketogenic diet (KD) can improve motor performance in the context of certain disease states, but it is unknown whether exogenous ketone supplements—alternatives to KDs—may have similar effects. Therefore, we investigated the effect of ketone supplements on motor performance, using accelerating rotarod test and on postexercise blood glucose and R-beta-hydroxybutyrate (R-βHB) levels in rodent models with and without pathology. The effect of KD, butanediol (BD), ketone-ester (KE), ketone-salt (KS), and their combination (KE + KS: KEKS) or mixtures with medium chain triglyceride (MCT) (KE + MCT: KEMCT; KS + MCT: KSMCT) was tested in Sprague-Dawley (SPD) and WAG/Rij (WR) rats and in GLUT-1 Deficiency Syndrome (G1D) mice. Motor performance was enhanced by KEMCT acutely, KE and KS subchronically in SPD rats, by KEKS and KEMCT groups in WR rats, and by KE chronically in G1D mice. We demonstrated that exogenous ketone supplementation improved motor performance to various degrees in rodent models, while effectively elevated R-βHB and in some cases offsets postexercise blood glucose elevations. Our results suggest that improvement of motor performance varies depending on the strain of rodents, specific ketone formulation, age, and exposure frequency.

Exogenous Ketones Lower Blood Glucose Level in Rested and Exercised Rodent Models

Diseases involving inflammation and oxidative stress can be exacerbated by high blood glucose levels. Due to tight metabolic regulation, safely reducing blood glucose can prove difficult. The ketogenic diet (KD) reduces absolute glucose and insulin, while increasing fatty acid oxidation, ketogenesis, and circulating levels of β-hydroxybutyrate (βHB), acetoacetate (AcAc), and acetone. Compliance to KD can be difficult, so alternative therapies that help reduce glucose levels are needed. Exogenous ketones provide an alternative method to elevate blood ketone levels without strict dietary requirements. In this study, we tested the changes in blood glucose and ketone (βHB) levels in response to acute, sub-chronic, and chronic administration of various ketogenic compounds in either a post-exercise or rested state. WAG/Rij (WR) rats, a rodent model of human absence epilepsy, GLUT1 deficiency syndrome mice (GLUT1D), and wild type Sprague Dawley rats (SPD) were assessed. Non-pathological animals were also assessed across different age ranges. Experimental groups included KD, standard diet (SD) supplemented with water (Control, C) or with exogenous ketones: 1, 3-butanediol (BD), βHB mineral salt (KS), KS with medium chain triglyceride/MCT (KSMCT), BD acetoacetate diester (KE), KE with MCT (KEMCT), and KE with KS (KEKS). In rested WR rats, the KE, KS, KSMCT groups had lower blood glucose level after 1 h of treatment, and in KE and KSMCT groups after 24 h. After exercise, the KE, KSMCT, KEKS, and KEMCT groups had lowered glucose levels after 1 h, and in the KEKS and KEMCT groups after 7 days, compared to control. In GLUT1D mice without exercise, only KE resulted in significantly lower glucose levels at week 2 and week 6 during a 10 weeks long chronic feeding study. In 4-month and 1-year-old SPD rats in the post-exercise trials, blood glucose was significantly lower in KD and KE, and in KEMCT groups, respectively. After seven days, the KSMCT group had the most significantly reduced blood glucose levels, compared to control. These results indicate that exogenous ketones were efficacious in reducing blood glucose levels within and outside the context of exercise in various rodent models of different ages, with and without pathology.

Impact of Repetitive Mild Traumatic Brain Injury on Behavioral and Hippocampal Deficits in a Mouse Model of Chronic Stress

Clinical studies examining the interaction between traumatic brain injury (TBI) and stress-related disorders (e.g., post-traumatic stress disorder) are often complicated by methodological constraints, such as heterogeneity in injury type and severity, time post-trauma, and predisposing risk factors. Developing relevant animal models whereby many variables can be efficiently controlled is thus essential to understanding this elusive relationship. Here, we use our repeated unpredictable stress (RUS) paradigm, in combination with our established mouse model of repetitive mild TBI (r-mTBI), to assess the impact of repeated exposures to these paradigms on behavioral and neurobiological measures. C57BL/6J male mice were exposed to RUS and r-mTBI at 3 and 6 months of age followed by batteries of behavioral testing. Mice were euthanized 10 days and 3 months post-exposure, with brain and plasma samples collected for molecular profiling. The RUS paradigm involved exposure to a predator odor (trimethylthiazoline; TMT) while under restraint, daily unstable social housing, five inescapable footshocks on separate days, and chronic social isolation. Animals receiving r-mTBI ( × 5) and stress were exposed to a single closed-head injury 1 h after each footshock. Stress-alone mice showed significant weight loss, recall of traumatic memories, and anxiety-like and passive stress-coping behavior when compared with control mice. However, in stress+r-mTBI animals, the changes in cued fear memory, anxiety, and stress-coping tests were diminished, possibly due to TBI-induced hyperactivity. We also report complex brain molecular and neuropathological findings. Stress and r-mTBI, either individually or comorbidly, were associated with a chronic reduction in dendritic spine GluN2A/GluN2B ratio in the hippocampus. While stress augmented the r-mTBI-dependent astrogliosis in the corpus callosum, it mitigated r-mTBI-induced increases in hippocampal pro-brain-derived neurotrophic factor. We anticipate that our model will be a good platform to untangle the complex comorbid pathophysiology in stress disorders and r-mTBI.

When a child dies of heatstroke after a parent or caretaker unknowingly leaves the child in a car: How does it happen and is it a crime?

It is commonly reported that in the course of a drive, a parent or caretaker loses awareness of the presence of a child in the back seat of the car. Upon arriving at the destination, the driver exits the car and unknowingly leaves the child in the car. This incomprehensible lapse of memory exposes forgotten children to hazards, including death from heatstroke. More than 400 children in the past 20 years have suffered from heatstroke after being unknowingly forgotten in cars. How can loving and attentive parents, with no evidence of substance abuse or an organic brain disorder, have a catastrophic lapse of memory that places a child's welfare in jeopardy? This article addresses this question at multiple levels of analysis. First, it is concluded that the loss of awareness of a child in a car is a failure of a type of memory referred to as prospective memory (PM), that is, failure to remember to execute a plan in the future. Second, factors that increase the likelihood that PM will fail are identified. Third, research on the neurobiology of PM and PM-related memory failures are reviewed, including a discussion of how competition between brain structures contributes to a failure of PM. Finally, the issue of whether a failure of PM that results in harm to a child qualifies as a criminal offence is discussed. Overall, this neuropsychological perspective on how catastrophic memory errors occur should be of value to the scientific community, the public and law-enforcement agencies.

Exogenous Ketone Supplementation Decreased the Lipopolysaccharide-Induced Increase in Absence Epileptic Activity in Wistar Albino Glaxo Rijswijk Rats

It has been demonstrated previously that exogenous ketone supplements such as ketone ester (KE) decreased absence epileptic activity in a well-studied animal model of human absence epilepsy, Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats. It is known that lipopolysaccharide (LPS)-generated changes in inflammatory processes increase absence epileptic activity, while previous studies show that ketone supplement-evoked ketosis can modulate inflammatory processes. Thus, we investigated in the present study whether administration of exogenous ketone supplements, which were mixed with standard rodent chow (containing 10% KE + 10% ketone salt/KS, % by weight, KEKS) for 10 days, can modulate the LPS-evoked changes in absence epileptic activity in WAG/Rij rats. At first, KEKS food alone was administered and changes in spike-wave discharge (SWD) number, SWD time, discharge frequency within SWDs, blood glucose, and beta-hydroxybutyrate (βHB) levels, as well as body weight and sleep-waking stages were measured. In a separate experiment, intraperitoneal (i.p.) injection of LPS (50 μg/kg) alone and a cyclooxygenase 1 and 2 (COX-1 and COX-2) inhibitor indomethacin (10 mg/kg) alone, as well as combined IP injection of indomethacin with LPS (indomethacin + LPS) were applied in WAG/Rij rats to elucidate their influences on SWD number. In order to determine whether KEKS food can modify the LPS-evoked changes in SWD number, KEKS food in combination with IP LPS (50 μg/kg) (KEKS + LPS), as well as KEKS food with IP indomethacin (10 mg/kg) and LPS (50 μg/kg) (KEKS + indomethacin + LPS) were also administered. We demonstrated that KEKS food significantly increased blood βHB levels and decreased not only the spontaneously generated absence epileptic activity (SWD number), but also the LPS-evoked increase in SWD number in WAG/Rij rats. Our results suggest that administration of exogenous ketone supplements (ketogenic foods) may be a promising therapeutic tool in the treatment of epilepsy.

Formal comment on "Systematic review of the predictors of statin adherence for the primary prevention of cardiovascular disease"

Statins have been prescribed for primary prevention of cardiovascular disease (CVD) for nearly 3 decades. Throughout this period key opinion leaders in the field have been dismayed by the high rate of non-adherence of patients to follow their statin regimen. Hope et al., [1] have addressed this issue by providing a systematic review of research on predictors of statin adherence for primary prevention of CVD. However, their review does not address the ongoing debate as to whether statin treatment is warranted for primary prevention of CVD, nor does it adequately address concerns regarding adverse effects of statins. We have therefore written a commentary which provides a broader perspective on the benefits versus harms of statin therapy. Our perspective of the literature is that non-adherence to statin treatment for primary prevention of CVD is justified because the meager benefits are more than offset by the extensive harms.

Elevated Plus Maze Test Combined with Video Tracking Software to Investigate the Anxiolytic Effect of Exogenous Ketogenic Supplements

The overall goal of this study is to describe the methodology of the elevated plus maze (EPM) test in combination with a video tracking software. The purpose of the method is to document the effect of various potential anxiolytic treatments on laboratory rodent models. The EPM test is based on the rodents' proclivity toward protected, enclosed dark spaces and unconditioned fear of open spaces and heights, and their innate intense motivation to explore novel environments. The EPM test is a widely used behavioral test for investigating the anxiolytic or anxiogenic responses of rodents given drugs that are known to affect behavior. Observation demonstrating a decreased proportion of time spent on closed arms, an increased proportion of time spent on open arms, a reduced number of entries to closed arms, and an elevated number of entries to open arms measured by the EPM test may reflect reduced anxiety levels. Using this method, the effect of exogenous ketone supplements on anxiety-related behavior is tested in Sprague Dawley (SPD) rats. Exogenous ketone supplements are chronically fed to the rats for 83 days or subchronically and acutely orally gavaged, daily for 7 days, before conducting the EPM test. Behavioral data collection is performed using the SMART video tracking system by a blinded observer at the end of the treatments. The main findings indicate that the EPM test is an effective method to detect the ketone supplement-induced anxiolytic effect and can be considered a sensitive measure to assess changes in anxiety behavior associated with drug- or metabolic-based therapies.

Delaying latency to hyperbaric oxygen-induced CNS oxygen toxicity seizures by combinations of exogenous ketone supplements

Central nervous system oxygen toxicity (CNS-OT) manifests as tonic-clonic seizures and is a limitation of hyperbaric oxygen therapy (HBOT), as well as of recreational and technical diving associated with elevated partial pressure of oxygen. A previous study showed that ketone ester (1,3-butanediol acetoacetate diester, KE) administration delayed latency to seizures (LS) in 3-month-old Sprague-Dawley (SD) rats. This study explores the effect of exogenous ketone supplements in additional dosages and formulations on CNS-OT seizures in 18 months old SD rats, an age group correlating to human middle age. Ketogenic agents were given orally 60 min prior to exposure to hyperbaric oxygen and included control (water), KE (10 g/kg), KE/2 (KE 5 g/kg + water 5 g/kg), KE + medium-chain triglycerides (KE 5 g/kg + MCT 5 g/kg), and ketone salt (Na+ /K+ βHB, KS) + MCT (KS 5 g/kg + MCT 5 g/kg). Rats were exposed to 100% oxygen at 5 atmospheres absolute (ATA). Upon seizure presentation (tonic-clonic movements) experiments were immediately terminated and blood was tested for glucose and D-beta-hydroxybutyrate (D-βHB) levels. While blood D-βHB levels were significantly elevated post-dive in all treatment groups, LS was significantly delayed only in KE (P = 0.0003), KE/2 (P = 0.023), and KE + MCT (P = 0.028) groups. In these groups, the severity of seizures appeared to be reduced, although these changes were significant only in KE-treated animals (P = 0.015). Acetoacetate (AcAc) levels were also significantly elevated in KE-treated animals. The LS in 18-month-old rats was delayed by 179% in KE, 219% in KE + MCT, and 55% in KE/2 groups, while only by 29% in KS + MCT. In conclusion, KE supplementation given alone and in combination with MCT elevated both βHB and AcAc, and delayed CNS-OT seizures.

LDL-C does not cause cardiovascular disease: a comprehensive review of the current literature

INTRODUCTION

For half a century, a high level of total cholesterol (TC) or low-density lipoprotein cholesterol (LDL-C) has been considered to be the major cause of atherosclerosis and cardiovascular disease (CVD), and statin treatment has been widely promoted for cardiovascular prevention. However, there is an increasing understanding that the mechanisms are more complicated and that statin treatment, in particular when used as primary prevention, is of doubtful benefit. Areas covered: The authors of three large reviews recently published by statin advocates have attempted to validate the current dogma. This article delineates the serious errors in these three reviews as well as other obvious falsifications of the cholesterol hypothesis. Expert commentary: Our search for falsifications of the cholesterol hypothesis confirms that it is unable to satisfy any of the Bradford Hill criteria for causality and that the conclusions of the authors of the three reviews are based on misleading statistics, exclusion of unsuccessful trials and by ignoring numerous contradictory observations.

Chronic Hippocampal Abnormalities and Blunted HPA Axis in an Animal Model of Repeated Unpredictable Stress

Incidence of post-traumatic stress disorder (PTSD) ranges from 3 to 30% in individuals exposed to traumatic events, with the highest prevalence in groups exposed to combat, torture, or rape. To date, only a few FDA approved drugs are available to treat PTSD, which only offer symptomatic relief and variable efficacy. There is, therefore, an urgent need to explore new concepts regarding the biological responses causing PTSD. Animal models are an appropriate platform for conducting such studies. Herein, we examined the chronic behavioral and neurobiological effects of repeated unpredictable stress (RUS) in a mouse model. 12 weeks-old C57BL/6J male mice were exposed to a 21-day RUS paradigm consisting of exposures to a predator odor (TMT) whilst under restraint, unstable social housing, inescapable footshocks and social isolation. Validity of the model was assessed by comprehensive examination of behavioral outcomes at an acute timepoint, 3 and 6 months post-RUS; and molecular profiling was also conducted on brain and plasma samples at the acute and 6 months timepoints. Stressed mice demonstrated recall of traumatic memories, passive stress coping behavior, acute anxiety, and weight gain deficits when compared to control mice. Immunoblotting of amygdala lysates showed a dysregulation in the p75NTR/ProBDNF, and glutamatergic signaling in stressed mice at the acute timepoint. At 6 months after RUS, stressed mice had lower plasma corticosterone, reduced hippocampal CA1 volume and reduced brain-derived neurotrophic factor levels. In addition, glucocorticoid regulatory protein FKBP5 was downregulated in the hypothalamus of stressed mice at the same timepoint, together implicating an impaired hypothalamus-pituitary-adrenal-axis. Our model demonstrates chronic behavioral and neurobiological outcomes consistent with those reported in human PTSD cases and thus presents a platform through which to understand the neurobiology of stress and explore new therapeutic interventions.

Atypical PKC, PKCλ/ι, activates β-secretase and increases Aβ1-40/42 and phospho-tau in mouse brain and isolated neuronal cells, and may link hyperinsulinemia and other aPKC activators to development of pathological and memory abnormalities in Alzheimer's disease

Hyperinsulinemia activates brain Akt and PKC-λ/ι and increases Aβ1-40/42 and phospho-tau in insulin-resistant animals. Here, we examined underlying mechanisms in mice, neuronal cells, and mouse hippocampal slices. Like Aβ1-40/42, β-secretase activity was increased in insulin-resistant mice and monkeys. In insulin-resistant mice, inhibition of hepatic PKC-λ/ι sufficient to correct hepatic abnormalities and hyperinsulinemia simultaneously reversed increases in Akt, atypical protein kinase C (aPKC), β-secretase, and Aβ1-40/42, and restored acute Akt activation. However, 2 aPKC inhibitors additionally blocked insulin's ability to activate brain PKC-λ/ι and thereby increase β-secretase and Aβ1-40/42. Furthermore, direct blockade of brain aPKC simultaneously corrected an impairment in novel object recognition in high-fat-fed insulin-resistant mice. In neuronal cells and/or mouse hippocampal slices, PKC-ι/λ activation by insulin, metformin, or expression of constitutive PKC-ι provoked increases in β-secretase, Aβ1-40/42, and phospho-thr-231-tau that were blocked by various PKC-λ/ι inhibitors, but not by an Akt inhibitor. PKC-λ/ι provokes increases in brain β-secretase, Aβ1-40/42, and phospho-thr-231-tau. Excessive signaling via PKC-λ/ι may link hyperinsulinemia and other PKC-λ/ι activators to pathological and functional abnormalities in Alzheimer's disease.

Development of an Intact Blood-Brain Barrier in Brain Tissue Transplants is Dependent on the Site of Transplantation

Transplantation of fetal septal forebrain tissue was performed to the anterior chamber of the eye, or intracranially to the rostral hippocampal formation in rats, to evaluate the impact of transplantation site on the development of an intact blood–brain barrier (BBB). The tissue was studied at 1, 2, 3, and 4 wk following transplantation by means of intravenous injection of Trypan blue, which is a vital stain not normally penetrating the BBB, as well as with an antibody specifically directed against the rat BBB, SMI71. In the intraocular septal transplants, there was a significant leakage of Trypan blue 1 wk postgrafting, associated with a few laminin-immunoreactive blood vessels that did not contain any SMI71-immunoreactivity. However, at 2 wk postgrafting, the intraocular grats exhibited an extensive plexus of thin-walled blood vessels expressing SMI71 immunoreactivity and no Trypan blue leakage. Thus, it appeared that a BBB had developed to some degree by 2 wk postgrafting in oculo. In the intracranial grafts, on the other hand, Trypan blue leakage could be seen as long as 3 wk postgrafting, and a dense plexus of blood vessels with SMI71 immunoreactivity was first seen at 4 wk postgrafting. Thus, the development of Trypan blue impermeability was delayed with 1 to 2 wk in the intracranial versus the intraocular grafts. Control experiments using psychological stress in adult rats as a means to transiently disrupt the BBB revealed that an increase in Trypan blue leakage correlated well with the disappearance of SMI71 immunoreactivity. Taken together, these studies demonstrate that the site of transplantation can influence the development of an intact BBB in neural tissue grafts.

Lack of an association or an inverse association between low-density-lipoprotein cholesterol and mortality in the elderly: a systematic review

OBJECTIVE

It is well known that total cholesterol becomes less of a risk factor or not at all for all-cause and cardiovascular (CV) mortality with increasing age, but as little is known as to whether low-density lipoprotein cholesterol (LDL-C), one component of total cholesterol, is associated with mortality in the elderly, we decided to investigate this issue.

SETTING, PARTICIPANTS AND OUTCOME MEASURES

We sought PubMed for cohort studies, where LDL-C had been investigated as a risk factor for all-cause and/or CV mortality in individuals ≥60 years from the general population.

RESULTS

We identified 19 cohort studies including 30 cohorts with a total of 68 094 elderly people, where all-cause mortality was recorded in 28 cohorts and CV mortality in 9 cohorts. Inverse association between all-cause mortality and LDL-C was seen in 16 cohorts (in 14 with statistical significance) representing 92% of the number of participants, where this association was recorded. In the rest, no association was found. In two cohorts, CV mortality was highest in the lowest LDL-C quartile and with statistical significance; in seven cohorts, no association was found.

CONCLUSIONS

High LDL-C is inversely associated with mortality in most people over 60 years. This finding is inconsistent with the cholesterol hypothesis (ie, that cholesterol, particularly LDL-C, is inherently atherogenic). Since elderly people with high LDL-C live as long or longer than those with low LDL-C, our analysis provides reason to question the validity of the cholesterol hypothesis. Moreover, our study provides the rationale for a re-evaluation of guidelines recommending pharmacological reduction of LDL-C in the elderly as a component of cardiovascular disease prevention strategies.

Predator-based psychosocial stress animal model of PTSD: Preclinical assessment of traumatic stress at cognitive, hormonal, pharmacological, cardiovascular and epigenetic levels of analysis

Research on post-traumatic stress disorder (PTSD) is faced with the challenge of understanding how a traumatic experience produces long-lasting detrimental effects on behavior and brain functioning, and more globally, how stress exacerbates somatic disorders, including cardiovascular disease. Moreover, the design of translational research needs to link animal models of PTSD to clinically relevant risk factors which address why only a subset of traumatized individuals develop persistent psychopathology. In this review, we have summarized our psychosocial stress rodent model of PTSD which is based on well-described PTSD-inducing risk factors, including a life-threatening experience, a sense of horror and uncontrollability, and insufficient social support. Specifically, our animal model of PTSD integrates acute episodes of inescapable exposure of immobilized rats to a predator with chronic daily social instability. This stress regimen produces PTSD-like effects in rats at behavioral, cognitive, physiological, pharmacological and epigenetic levels of analysis. We have discussed a recent extension of our animal model of PTSD in which stress exacerbated coronary pathology following an ischemic event, assessed in vitro. In addition, we have reviewed our research investigating pharmacological and non-pharmacological therapeutic strategies which may have value in clinical approaches toward the treatment of traumatized people. Overall, our translational approach bridges the gap between human and animal PTSD research to create a framework with which to enhance our understanding of the biological basis of trauma-induced pathology and to assess therapeutic approaches in the treatment of psychopathology.

Influence of pharmacological manipulations of NMDA and cholinergic receptors on working versus reference memory in a dual component odor span task

Developed as a tool to assess working memory capacity in rodents, the odor span task (OST) has significant potential to advance drug discovery in animal models of psychiatric disorders. Prior investigations indicate OST performance is impaired by systemic administration of N-methyl-d-aspartate receptor (NMDA-r) antagonists and is sensitive to cholinergic manipulations. The present study sought to determine whether an impairment in OST performance can be produced by systemic administration of the competitive NMDA-r antagonist 3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP; 3, 10, 17 mg/kg i.p.) in a unique dual-component variant of the OST, and whether this impairment is ameliorated by nicotine (0.75 mg/kg i.p.). Male Sprague-Dawley rats were trained to asymptotic level of performance on a 24-trial two-comparison incrementing nonmatching to sample OST. In addition, rats were administered a two-comparison olfactory reference memory (RM) task, which was integrated into the OST. The RM task provided an assessment of the effects of drug administration on global behavioral measures, long-term memory and motivation. Several measures of working memory (span, longest run, and accuracy) were dose dependently impaired by CPP without adversely affecting RM. Analysis of drug effects across trial blocks demonstrated a significant impairment of performance even at low memory loads, suggesting a CPP-induced deficit of olfactory short-term memory that is not load-dependent. Although nicotine did not ameliorate CPP-induced impairments in span or accuracy, it did block the impairment in longest run produced by the 10 mg/kg dose of CPP. Overall, our results indicate that performance in our 24 odor two-comparison OST is capacity dependent and that CPP impaired OST working, but not reference, memory.

Influence of daily social stimulation on behavioral and physiological outcomes in an animal model of PTSD

INTRODUCTION

We have shown in previous work that acute episodes of predator exposure occurring in the context of chronic social instability produced PTSD-like sequelae in rats. Our animal model of PTSD contained two components: (1) acute trauma, immobilization of rats in close proximity to a cat twice in 10 days, and (2) chronic social instability, 31 days of randomized housing of cage cohorts. Here we tested the hypothesis that daily social stimulation would block the development of the PTSD-like sequelae.

METHODS

Beginning 24 h after the first cat exposure, adult male rats were given our established PTSD model, alone or in conjunction with daily social stimulation, in which all rats within a group interacted in a large apparatus for 2 h each day for the final 30 days of the PTSD regimen. All behavioral, for example, anxiety, memory, startle testing, and physiological assessments, for example, body growth, organ weights, and corticosterone levels, took place following completion of the psychosocial stress period.

RESULTS

Daily social stimulation blocked the expression of a subset of PTSD-like effects, including predator-based cued fear conditioning, enhanced startle response, heightened anxiety on the elevated plus maze and the stress-induced suppression of growth rate. We also found that social stimulation and psychosocial stress produced equivalent outcomes in some measures, including adrenal and heart hypertrophy, thymus atrophy, and a reduction in poststress corticosterone levels.

CONCLUSIONS

Daily exposure of rats to a highly social environment blocked the development of a subset of trauma-induced sequelae, particularly fear-related outcomes. It is notable that daily social stimulation normalized a subset, but not all, of the PTSD-like effects. We discuss our findings in the context of the literature demonstrating that social stimulation can counteract the adverse effects of traumatic stress on behavioral and physiological measures, as well as to produce its own stress-like outcomes.

Genetic and environmental modulation of neurodevelopmental disorders: Translational insights from labs to beds

Neurodevelopmental disorders (NDDs) are a heterogeneous group of prevalent neuropsychiatric illnesses with various degrees of social, cognitive, motor, language and affective deficits. NDDs are caused by aberrant brain development due to genetic and environmental perturbations. Common NDDs include autism spectrum disorder (ASD), intellectual disability, communication/speech disorders, motor/tic disorders and attention deficit hyperactivity disorder. Genetic and epigenetic/environmental factors play a key role in these NDDs with significant societal impact. Given the lack of their efficient therapies, it is important to gain further translational insights into the pathobiology of NDDs. To address these challenges, the International Stress and Behavior Society (ISBS) has established the Strategic Task Force on NDDs. Summarizing the Panel's findings, here we discuss the neurobiological mechanisms of selected common NDDs and a wider NDD+ spectrum of associated neuropsychiatric disorders with developmental trajectories. We also outline the utility of existing preclinical (animal) models for building translational and cross-diagnostic bridges to improve our understanding of various NDDs.

Dysfunctional or hyperfunctional? The amygdala in posttraumatic stress disorder is the bull in the evolutionary China shop

Our motivation in writing this Review arose not only from the great value in contributing to this special issue of the Journal of Neuroscience Research but also from the desire to express our opinion that the description of the amygdala as "dysfunctional" in posttraumatic stress disorder (PTSD) might not be appropriate. We acknowledge that excessive activation of the amygdala contributes to the cluster of PTSD symptoms, including hypervigilance, intrusive memories, and impaired sleep, that underlies the devastating mental and physical outcomes in trauma victims. The issue that we address is whether the symptoms of PTSD represent an impaired (dysfunctional) or sensitized (hyperfunctional) amygdala status. We propose that the amygdala in PTSD is hyperfunctional rather than dysfunctional in recognition of the fact that the individual has already survived one life-threatening attack and that another may be forthcoming. We therefore consider PTSD to be a state in which the amygdala is functioning optimally if the goal is to ensure a person's survival. The misery caused by a hyperfunctional amygdala in PTSD is the cost of inheriting an evolutionarily primitive mechanism that considers survival more important than the quality of one's life.

Differential effects of sertraline in a predator exposure animal model of post-traumatic stress disorder

Serotonin (5-HT), norepinephrine (NE), and other neurotransmitters are modulated in post-traumatic stress disorder (PTSD). In addition, pro-inflammatory cytokines (PIC) are elevated during the progression of the disorder. Currently, the only approved pharmacologic treatments for PTSD are the selective-serotonin reuptake inhibitors (SSRI) sertraline and paroxetine, but their efficacy in treating PTSD is marginal at best. In combat-related PTSD, SSRIs are of limited effectiveness. Thus, this study sought to analyze the effects of the SSRI sertraline on inflammation and neurotransmitter modulation via a predator exposure/psychosocial stress animal model of PTSD. We hypothesized that sertraline would diminish inflammatory components and increase 5-HT but might also affect levels of other neurotransmitters, particularly NE. PTSD-like effects were induced in male Sprague-Dawley rats (n = 6/group × 4 groups). The rats were secured in Plexiglas cylinders and placed in a cage with a cat for 1 h on days 1 and 11 of a 31-day stress regimen. PTSD rats were also subjected to psychosocial stress via daily cage cohort changes. At the conclusion of the stress regimen, treatment group animals were injected intraperitoneally (i.p.) with sertraline HCl at 10 mg/kg for 7 consecutive days, while controls received i.p. vehicle. The animals were subsequently sacrificed on day 8. Sertraline attenuated inflammatory markers and normalized 5-HT levels in the central nervous system (CNS). In contrast, sertraline produced elevations in NE in the CNS and systemic circulation of SSRI treated PTSD and control groups. This increase in NE suggests SSRIs produce a heightened noradrenergic response, which might elevate anxiety in a clinical setting.

Neurobehavioral, neuropathological and biochemical profiles in a novel mouse model of co-morbid post-traumatic stress disorder and mild traumatic brain injury

Co-morbid mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) has become the signature disorder for returning combat veterans. The clinical heterogeneity and overlapping symptomatology of mTBI and PTSD underscore the need to develop a preclinical model that will enable the characterization of unique and overlapping features and allow discrimination between both disorders. This study details the development and implementation of a novel experimental paradigm for PTSD and combined PTSD-mTBI. The PTSD paradigm involved exposure to a danger-related predator odor under repeated restraint over a 21 day period and a physical trauma (inescapable footshock). We administered this paradigm alone, or in combination with a previously established mTBI model. We report outcomes of behavioral, pathological and biochemical profiles at an acute timepoint. PTSD animals demonstrated recall of traumatic memories, anxiety and an impaired social behavior. In both mTBI and combination groups there was a pattern of disinhibitory like behavior. mTBI abrogated both contextual fear and impairments in social behavior seen in PTSD animals. No major impairment in spatial memory was observed in any group. Examination of neuroendocrine and neuroimmune responses in plasma revealed a trend toward increase in corticosterone in PTSD and combination groups, and an apparent increase in Th1 and Th17 proinflammatory cytokine(s) in the PTSD only and mTBI only groups respectively. In the brain there were no gross neuropathological changes in any groups. We observed that mTBI on a background of repeated trauma exposure resulted in an augmentation of axonal injury and inflammatory markers, neurofilament L and ICAM-1 respectively. Our observations thus far suggest that this novel stress-trauma-related paradigm may be a useful model for investigating further the overlapping and distinct spatio-temporal and behavioral/biochemical relationship between mTBI and PTSD experienced by combat veterans.

Accelerated Resolution Therapy for treatment of pain secondary to symptoms of combat-related posttraumatic stress disorder

BACKGROUND

As many as 70% of veterans with chronic pain treated within the US Veterans Administration (VA) system may have posttraumatic stress disorder (PTSD), and conversely, up to 80% of those with PTSD may have pain. We describe pain experienced by US service members and veterans with symptoms of PTSD, and report on the effect of Accelerated Resolution Therapy (ART), a new, brief exposure-based therapy, on acute pain reduction secondary to treatment of symptoms of PTSD.

METHODS

A randomized controlled trial of ART versus an attention control (AC) regimen was conducted among 45 US service members/veterans with symptoms of combat-related PTSD. Participants received a mean of 3.7 sessions of ART.

RESULTS

Mean age was 41.0 + 12.4 years and 20% were female. Most veterans (93%) reported pain. The majority (78%) used descriptive terms indicative of neuropathic pain, with 29% reporting symptoms of a concussion or feeling dazed. Mean pre-/post-change on the Pain Outcomes Questionnaire (POQ) was -16.9±16.6 in the ART group versus -0.7±14.2 in the AC group (p=0.0006). Among POQ subscales, treatment effects with ART were reported for pain intensity (effect size = 1.81, p=0.006), pain-related impairment in mobility (effect size = 0.69, p=0.01), and negative affect (effect size = 1.01, p=0.001).

CONCLUSIONS

Veterans with symptoms of combat-related PTSD have a high prevalence of significant pain, including neuropathic pain. Brief treatment of symptoms of combat-related PTSD among veterans by use of ART appears to acutely reduce concomitant pain.

Influence of post-traumatic stress disorder on neuroinflammation and cell proliferation in a rat model of traumatic brain injury

Long-term consequences of traumatic brain injury (TBI) are closely associated with the development of severe psychiatric disorders, such as post-traumatic stress disorder (PTSD), yet preclinical studies on pathological changes after combined TBI with PTSD are lacking. In the present in vivo study, we assessed chronic neuroinflammation, neuronal cell loss, cell proliferation and neuronal differentiation in specific brain regions of adult Sprague-Dawley male rats following controlled cortical impact model of moderate TBI with or without exposure to PTSD. Eight weeks post-TBI, stereology-based histological analyses revealed no significant differences between sham and PTSD alone treatment across all brain regions examined, whereas significant exacerbation of OX6-positive activated microglial cells in the striatum, thalamus, and cerebral peduncle, but not cerebellum, in animals that received TBI alone and combined TBI-PTSD compared with PTSD alone and sham treatment. Additional immunohistochemical results revealed a significant loss of CA3 pyramidal neurons in the hippocampus of TBI alone and TBI-PTSD compared to PTSD alone and sham treatment. Further examination of neurogenic niches revealed a significant downregulation of Ki67-positive proliferating cells, but not DCX-positive neuronally migrating cells in the neurogenic subgranular zone and subventricular zone for both TBI alone and TBI-PTSD compared to PTSD alone and sham treatment. Comparisons of levels of neuroinflammation and neurogenesis between TBI alone and TBI+PTSD revealed that PTSD did not exacerbate the neuropathological hallmarks of TBI. These results indicate a progressive deterioration of the TBI brain, which, under the conditions of the present approach, was not intensified by PTSD, at least within our time window and within the examined areas of the brain. Although the PTSD manipulation employed here did not exacerbate the pathological effects of TBI, the observed long-term inflammation and suppressed cell proliferation may evolve into more severe neurodegenerative diseases and psychiatric disorders currently being recognized in traumatized TBI patients.

Animal models in translational studies of PTSD

Understanding the neurobiological mechanisms of post-traumatic stress disorder (PTSD) is of vital importance for developing biomarkers and more effective pharmacotherapy for this disorder. The design of bidirectional translational studies addressing all facets of PTSD is needed. Animal models of PTSD are needed not only to capture the complexity of PTSD behavioral characteristics, but also to address experimentally the influence of variety of factors which might determine an individual's vulnerability or resilience to trauma, e.g., genetic predisposition, early-life experience and social support. The current review covers recent translational approaches to bridge the gap between human and animal PTSD research and to create a framework for discovery of biomarkers and novel therapeutics.

Differential effectiveness of tianeptine, clonidine and amitriptyline in blocking traumatic memory expression, anxiety and hypertension in an animal model of PTSD

Individuals exposed to life-threatening trauma are at risk for developing post-traumatic stress disorder (PTSD), a debilitating condition that involves persistent anxiety, intrusive memories and several physiological disturbances. Current pharmacotherapies for PTSD manage only a subset of these symptoms and typically have adverse side effects which limit their overall effectiveness. We evaluated the effectiveness of three different pharmacological agents to ameliorate a broad range of PTSD-like symptoms in our established predator-based animal model of PTSD. Adult male Sprague-Dawley rats were given 1-h cat exposures on two occasions that were separated by 10 days, in conjunction with chronic social instability. Beginning 24 h after the first cat exposure, rats received daily injections of amitriptyline, clonidine, tianeptine or vehicle. Three weeks after the second cat exposure, all rats underwent a battery of behavioral and physiological tests. The vehicle-treated, psychosocially stressed rats demonstrated a robust fear memory for the two cat exposures, as well as increased anxiety expressed on the elevated plus maze, an exaggerated startle response, elevated heart rate and blood pressure, reduced growth rate and increased adrenal gland weight, relative to the vehicle-treated, non-stressed (control) rats. Neither amitriptyline nor clonidine was effective at blocking the entire cluster of stress-induced sequelae, and each agent produced adverse side effects in control subjects. Only the antidepressant tianeptine completely blocked the effects of psychosocial stress on all of the physiological and behavioral measures that were examined. These findings illustrate the differential effectiveness of these three treatments to block components of PTSD-like symptoms in rats, and in particular, reveal the profile of tianeptine as the most effective of all three agents.

Current status on behavioral and biological markers of PTSD: a search for clarity in a conflicting literature

Extensive research has identified stereotypic behavioral and biological abnormalities in post-traumatic stress disorder (PTSD), such as heightened autonomic activity, an exaggerated startle response, reduced basal cortisol levels and cognitive impairments. We have reviewed primary research in this area, noting that factors involved in the susceptibility and expression of PTSD symptoms are more complex and heterogeneous than is commonly stated, with extensive findings which are inconsistent with the stereotypic behavioral and biological profile of the PTSD patient. A thorough assessment of the literature indicates that interactions among myriad susceptibility factors, including social support, early life stress, sex, age, peri- and post-traumatic dissociation, cognitive appraisal of trauma, neuroendocrine abnormalities and gene polymorphisms, in conjunction with the inconsistent expression of the disorder across studies, confounds attempts to characterize PTSD as a monolithic disorder. Overall, our assessment of the literature addresses the great challenge in developing a behavioral and biomarker-based diagnosis of PTSD.

Brief treatment of co-occurring post-traumatic stress and depressive symptoms by use of accelerated resolution therapy(®)

This uncontrolled prospective cohort study evaluated the use of accelerated resolution therapy (ART) for treatment of comorbid symptoms of post-traumatic stress disorder (PTSD) and major depressive disorder. Twenty-eight adult subjects, mean age of 41 years (79% female, 36% Hispanic), received a mean of 3.7 ± 1.1 ART treatment sessions (range 1-5). ART is a new exposure-based psychotherapy that makes use of eye movements. Subjects completed a range of self-report psychological measures before and after treatment with ART including the 17-item PCL-C checklist (symptoms of PTSD) and 20-item Center for Epidemiologic Studies Depression Scale (CES-D). For the PCL-C, the pre-ART mean (±standard deviation) was 62.5 (8.8) with mean reductions of -29.6 (12.5), -30.1 (13.1), and -31.4 (14.04) at post-ART, 2-month, and 4-month follow-up, respectively (p < 0.0001 for comparisons to pre-ART score). Compared to pre-ART status, this corresponded to standardized effect sizes of 2.37, 2.30, and 3.01, respectively. For the CES-D, the pre-ART mean was 35.1 (8.8) with mean reductions of -20.6 (11.0), -18.1 (11.5), and -15.6 (14.4) at post-ART, 2-month, and 4-month follow-up, respectively (p ≤ 0.0001 compared to Pre-ART score). This corresponded to standardized effect sizes of 1.88, 1.58, and 1.09, respectively. Strong correlations were observed at 2-month and 4-month follow-up for post-treatment changes in PTSD and depression symptom scores (r = 0.79, r = 0.76, respectively, p ≤ 0.0002). No serious treatment-related adverse effects were reported. In summary, ART appears to be a promising brief, safe, and effective treatment for adults with clinically significant comorbid symptoms of PTSD and depression. Future controlled and mechanistic studies with this emerging therapy are warranted, particularly given its short treatment duration, and in light of current heightened emphasis on health care cost constraints.

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

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