Environmental Oestrogens: Foe or Friend?

Oestrogens act throughout the body and are important "shapers" of development, including of brain sexual differentiation. This has raised concern that environmental oestrogens could affect such processes. However, experience with studies of the male reproductive tract suggests that most environmental oestrogens are too weak to pose such a threat. Conversely, as emerging data suggest that oestrogens have health-beneficial effects on the brain, could environmental oestrogens actually be good for us?     

Fever and sickness behavior: Friend or foe?

Fever has been recognized as an important symptom of disease since ancient times. For many years, fever was treated as a putative life-threatening phenomenon. More recently, it has been recognized as an important part of the body’s defense mechanisms; indeed at times it has even been used as a therapeutic agent. The knowledge of the functional role of the central nervous system in the genesis of fever has greatly improved over the last decade. It is clear that the febrile process, which develops in the sick individual, is just one of many brain-controlled sickness symptoms. Not only will the sick individual appear “feverish” but they may also display a range of behavioral changes, such as anorexia, fatigue, loss of interest in usual daily activities, social withdrawal, listlessness or malaise, hyperalgesia, sleep disturbances and cognitive dysfunction, collectively termed “sickness behavior”. In this review we consider the issue of whether fever and sickness behaviors are friend or foe during: a critical illness, the common cold or influenza, in pregnancy and in the newborn. Deciding whether these sickness responses are beneficial or harmful will very much shape our approach to the use of antipyretics during illness.     

Neural immunity: Friend or foe?

The articles compiled in this special edition of Journal of NeuroVirology target a developing field of investigation seeking to uncover how the immune system affects both the pathogenic process and protection against the ravages of neurodegenerative processes. Whether caused by a microbe, trauma, toxic metabolite, autoimmunity, or part of a wide degenerative process, immune dysfunction commonly affects central nervous system (CNS) disease. All together, the work presented here proved to be a unique undertaking with contributing scientists outside the field of neurovirology. Indeed, multiple disciplines including molecular neuroscience, neuroimmunology, virology, cellular immunology, receptor pharmacology, neuronal electrophysiology, neurochemistry, clinical neurology, and development neurobiology were joined. The basis of this work rests with the hypothesis that brain mononuclear phagocytes (MP; perivascular and brain macrophages and microglia) act as inducers of disease by engaging the immune system to protect, defend, or induce neural injury. Indeed, it is the brain MP that act as scavengers killing microblial pathogens, regulate immune responses through antigen presentation and mobilization of adaptive immune activities, and affect the production of neurotrophic or toxic secretory factors that incite disease processes. For many years, these responses were thought to be reactive to ongoing disease mechanisms with little effects on disease itself, let alone repair. The works compiled in this issue demonstrate quite clearly this is no longer true. Immune responses cannot be directed only against a microbe but also against self-antigens that are expressed in damaged CNS, leading to innate neurotoxic or adaptive anti-self immunity that commonly follow viral infections. Importantly, therapeutic modalities may take advantage of CNS immune responses through vaccination generating neuroprotection. Together, these articles serve to bring together common neuroimmune links between highly divergent diseases (for example, Parkinson's and Alzheimer's disease and human immunodeficiency virus type-one dementia). In the end, I hope this work will serve as discussion points for future collaborations and began to break down the barriers of disease, enabling targeted research activities toward what we have in common.     

Progesterone – Friend or foe?

Estradiol is the “prototypic” sex hormone of women. Yet, women have another sex hormone, which is often disregarded: Progesterone. The goal of this article is to provide a comprehensive review on progesterone, and its metabolite allopregnanolone, emphasizing three key areas: biological properties, main functions, and effects on mood in women. Recent years of intensive research on progesterone and allopregnanolone have paved the way for new treatment of postpartum depression. However, treatment for premenstrual syndrome and premenstrual dysphoric disorder as well as contraception that women can use without risking mental health problems are still needed. As far as progesterone is concerned, we might be dealing with a two-edged sword: while its metabolite allopregnanolone has been proven useful for treatment of PPD, it may trigger negative symptoms in women with PMS and PMDD. Overall, our current knowledge on the beneficial and harmful effects of progesterone is limited and further research is imperative.     

Pervasive Developmental Disorders and Autism Spectrum Disorders: Are These Disorders One and the Same?

The concept of pervasive developmental disorders (PDD) and autism spectrum disorders (ASD) closely resemble each other. Both ICD-10 and DSM-IV use the term PDD. The authors surveyed the perception of PDD/ASD and attitudes toward terminology. The subjects of this study were 205 medical/social-welfare professionals working in fields relating to developmental disorders. Questionnaires were mailed to site investigators at the collaborating institutes. With regard to what the scope of ASD and PDD encompasses, the answers were almost equally divided among three views: ASD and PDD are the same, PDD is wider in scope and ASD is wider. The terms PDD and autism were used in slightly different ways depended upon the situation. Our results demonstrate that the parameters of PDD and ASD are unclear and that the terms related to PDD/ASD are often used differently. Further studies are required to develop more clear and reliable diagnostic criteria for PDD.     

Treatments and Services for Neurodevelopmental Disorders on Advocacy Websites: Information or Evaluation?

The Internet has quickly gained popularity as a major source of health-related information, but its impact is unclear. Here, we investigate the extent to which advocacy websites for three neurodevelopmental disorders??cerebral palsy (CP), autism spectrum disorder (ASD) and fetal alcohol spectrum disorder (FASD)??inform stakeholders about treatment options, and discuss the ethical challenges inherent in providing such information online. We identified major advocacy websites for each disorder and assessed website accountability, the number, attributes, and accessibility of treatments described, and the valence of treatment information. With the exception of FASD websites, we found that advocacy websites provide a plethora of information about a wide variety of readily available products and services. Treatment information is primarily targeted at families and is overwhelmingly encouraging, regardless of the type or conventionality of treatments. Many websites acknowledge corporate sponsors. While the majority do not overtly advertise or endorse specific brands, they also do not prominently display disclaimers about the nature and intent of treatment information. Thus, while advocacy websites are organized to serve as information clearinghouses, they implicitly appear to provide endorsement of selected treatments and services. We conclude with recommendations for new partnerships between government-funded health organizations, advocacy and investigators to make more transparent the role of online information in informing treatment options and improving the evaluation of information.     

Can Autism Spectrum Disorders and Social Anxiety Disorders be Differentiated by the Social Responsiveness Scale in Children and Adolescents?

Autism spectrum disorder (ASD) as well as social phobia (SP), and selective mutism (SM) are characterised by impaired social interaction. We assessed the validity of the Social Responsiveness Scale (SRS) to differentiate between ASD, and SP/SM. Raw scores were compared in 6–18 year old individuals with ASD (N = 60), SP (N = 38), SM (N = 43), and typically developed (N = 42). Sensitivity and specificity were examined. The three disorders showed overlapping SRS scores. Especially in boys with SM (ROC–AUC = .81), presence of ASD was overestimated by the SRS. A combination of three disorder specific questionnaires resulted in marginally improved diagnostic accuracy. For the clinically very relevant differential diagnosis of SP/SM, SRS results must be interpreted with caution.     

Altered Brain Reward Circuits in Eating Disorders: Chicken or Egg?

The eating disorders anorexia nervosa (AN) and bulimia nervosa (BN) are severe psychiatric disorders with high mortality. Our knowledge about the neurobiology of eating disorders is very limited, and the question remains whether alterations in brain structure or function in eating disorders are state related, remnants of the illness or premorbid traits. The brain reward system is a relatively well-characterized brain circuitry that plays a central role in the drive to eat and individuals with current or past eating disorders showed alterations in those pathways compared to controls. Here we propose that structural and functional alterations in the insula and frontal cortex, including orbitofrontal and cingulate regions, areas that contribute to reward and anxiety processing, could predispose to developing an eating disorder and that adaptive changes in those circuits in response to malnutrition or repeated binge eating and purging could further promote illness behavior, hinder recovery and contribute to relapse.     

Cannabinoids, opioids and eating behavior: the molecular face of hedonism?

Obesity represents nowadays one of the most devastating health threats. Published reports even project a decline in life expectancy of US citizens due to the rapidly increasing prevalence of obesity. This alarming increase is intimately linked with recent changes of environment and lifestyle in western countries. In this context, the rewarding or even addictive properties of popular food may represent one of the most serious obstacles to overcome for an effective anti-obesity therapy. Therefore, in addition to molecular networks controlling energy homeostasis, now researchers are starting to define central nervous mechanisms governing hedonic and addictive components of food intake. A recently emerging body of data suggests that the endogenous cannabinoid and opioid systems both represent key circuits responding to the rewarding value of food. This review focuses on the role of these two systems for the homeostatic and hedonic aspects of eating behavior and includes their anatomical and functional interactions. Independent from the degree to which eating can be considered an addiction, cannabinoid and opioid receptor antagonists are promising anti-obesity drugs, since they are targeting both hedonic and homeostatic components of energy balance control.     

Cannabinoids and the immune system: potential for the treatment of inflammatory diseases?

Since the discovery of the cannabinoid receptors and their endogenous ligands, significant advances have been made in studying the physiological function of the endocannabinoid system. The presence of cannabinoid receptors on cells of the immune system and anecdotal and historical evidence suggesting that cannabis use has potent immuno-modulatory effects, has led to research directed at understanding the function and role of these receptors within the context of immunological cellular function. Studies from chronic cannabis smokers have provided much of the evidence for immunomodulatory effects of cannabis in humans, and animal and in vitro studies of immune cells such as T cells and macrophages have also provided important evidence. Cannabinoids can modulate both the function and secretion of cytokines from immune cells. Therefore, cannabinoids may be considered for treatment of inflammatory disease. This review article will highlight recent research on cannabinoids and how they interact with the immune system and also their potential use as therapeutic agents for a number of inflammatory disorders.     

Unsecured Intracranial Aneurysms and Induced Hypertension in Cerebral Vasospasm: Is Induced Hypertension Safe?

Background  

Induced hypertension is an established therapy to treat cerebral vasospasm (CVS) following subarachnoid hemorrhage (SAH) to prevent delayed ischemic deficits. Currently, there is minimal evidence available assessing the risk of induced hypertension in the presence of unsecured aneurysms. The aim of this study was to investigate the impact of induced hypertension on the rupturing of unsecured aneurysms in treating CVS.