D2 autoreceptor switches CB2 receptor effects on [3H]-dopamine release in the striatum

CB₂ receptors (CB₂R) are expressed in midbrain neurons. To evidence the control of dopamine release in dorsal striatum by CB₂R, we performed experiments of [³H]-dopamine release in dorsal striatal slices. We found a paradoxical increase in K⁺-induced [³H]-dopamine release by CB₂R activation with GW 833972A and JWH 133 two selective agonist. To understand the mechanism involved, we tested for a role of the D₂ autoreceptor in this effect; because in pallidal structures, the inhibitory effect of CB₁ receptors (CB₁R) on GABA release is switched to a stimulatory effect by D₂ receptors (D₂R). We found that the blockade of D₂ autoreceptors with sulpiride prevented the stimulatory effect of CB₂R activation; in fact, under this condition, CB₂R decreased dopamine release, indicating the role of the D₂ autoreceptor in the paradoxical increase. We also found that the effect occurs in nigrostriatal terminals, since lesions with 6-OH dopamine in the middle forebrain bundle prevented CB₂R effects on release. In addition, D₂–CB₂R interaction promoted cAMP accumulation, and the increase in [³H]-dopamine release was prevented by PKA blockade. D₂–CB₂R coprecipitation and proximity ligation assay studies indicated a close interaction of receptors that could participate in the observed effects. Finally, intrastriatal injection of CB₂R agonist induced contralateral turning in amphetamine-treated rats, which was prevented by sulpiride, indicating the role of the interaction in motor behavior. Thus, these data indicate that the D₂ autoreceptor switches, from inhibitory to stimulatory, the CB₂R effects on dopamine release, involving the cAMP → PKA pathway in nigrostriatal terminals.     

PTSD’s risky behavior criterion: Associated risky and unhealthy behaviors and psychiatric correlates in a nationally representative sample

Criterion E2 (“reckless or self-destructive behavior”) was added to the DSM-5 posttraumatic stress disorder (PTSD) criteria to reflect the established association between PTSD and risky and unhealthy behaviors (RUBs); however, previous research has questioned its clinical significance. To determine whether criterion E2 adequately captures reckless/self-destructive behavior, we examined the prevalence and associations of RUBs (e.g., substance misuse, risky sexual behaviors) with criterion E2 endorsement. Further, we examined associations between criterion E2 and psychiatric conditions (e.g., depressive disorders, anxiety disorders) in a population-based sample of trauma-exposed adults. We analyzed data from the 2012–2013 National Epidemiologic Survey on Alcohol and Related Conditions (N = 36,309). The Alcohol Use Disorder and Associated Disabilities Interview Schedule-5 assessed lifetime DSM-5 psychiatric conditions and self-reported RUBs. Among trauma-exposed adults (n = 23,936), multiple logistic regressions examined criterion E2′s associations with RUBs and psychiatric conditions. After adjusting for covariates, all RUBs were associated with E2 endorsement (AOR range: 1.58–3.97; most prevalent RUB among those who endorsed E2: greater substance use than intended [57.0 %]) except binge eating, and E2 endorsement was associated with increased odds of PTSD, bipolar disorder, substance use disorders, and schizotypal, borderline, and antisocial personality disorders (AOR range: 1.65–2.75), and decreased odds of major depressive disorder (AOR = 0.76). Results support the clinical significance of criterion E2 through identifying associated RUBs and distinct correlates. These results may inform screening and intervention strategies for at-risk populations.     

Nutritional and immunological factors in breast milk: A role in the intergenerational transmission from maternal psychopathology to child development

Perinatal psychopathologies affect more than 25% of women during and after their gestational period. These psychiatric disorders can potentially determine important biological variations in their organisms, affecting many different physiological and metabolic pathways. Of relevance, any of these changes occurring in the mother can alter the normal composition of breast milk, particularly the concentration of nutritional and inflammatory components, which play a role in child brain functioning and development. Indeed, there is evidence showing that changes in milk composition can contribute to cognitive impairments and alterations in mental abilities in children. This review aims to shed light on the unique intergenerational role played by breast milk composition, from maternal psychopathologies to child development.     

Amelioration of neurobehavioral and cognitive abilities of F1 progeny following dietary supplementation with Spirulina to protein malnourished mothers

Early life adversities (stress, infection and mal/undernutrition) can affect neurocognitive, hippocampal and immunological functioning of the brain throughout life. Substantial evidence suggests that maternal protein malnutrition contributes to the progression of neurocognitive abnormalities and psychopathologies in adolescence and adulthood in offspring. Maternal malnutrition is prevalent in low and middle resource populations. The present study was therefore undertaken to evaluate the effects of dietary Spirulina supplementation of protein malnourished mothers during pregnancy and lactation on their offspring’s reflex, neurobehavioral and cognitive development. Spirulina is a Cyanobacterium and a major source of protein and is being used extensively as a dynamic nutraceutical against aging and neurodegeneration. Sprague Dawley rats were switched to low protein (8% protein) or normal protein (20% protein) diet for 15 days before conception. Spirulina was orally administered (400 mg/kg/b.wt.) to subgroups of pregnant females from the day of conception throughout the lactational period. We examined several parameters including reproductive performance of dams, physical development, postnatal reflex ontogeny, locomotor behavior, neuromuscular strength, anxiety, anhedonic behavior, cognitive abilities and microglia populations in the F1 progeny. The study showed improved reproductive performance of Spirulina supplemented protein malnourished dams, accelerated acquisition of neurological reflexes, better physical appearance, enhanced neuromuscular strength, improved spatial learning and memory and partly normalized PMN induced hyperactivity, anxiolytic and anhedonic behavior in offspring. These beneficial effects of Spirulina consumption were also accompanied by reduced microglial activation which might assist in restoring the behavioral and cognitive skills in protein malnourished F1 rats. Maternal Spirulina supplementation is therefore proposed as an economical nutraceutical/supplement to combat malnutrition associated behavioral and cognitive deficits.     

Mold inhalation causes innate immune activation,neural, cognitive and emotional dysfunction

Individuals living or working in moldy buildings complain of a variety of health problems including pain, fatigue, increased anxiety, depression, and cognitive deficits. The ability of mold to cause such symptoms is controversial since no published research has examined the effects of controlled mold exposure on brain function or proposed a plausible mechanism of action. Patient symptoms following mold exposure are indistinguishable from those caused by innate immune activation following bacterial or viral exposure. We tested the hypothesis that repeated, quantified doses of both toxic and nontoxic mold stimuli would cause innate immune activation with concomitant neural effects and cognitive, emotional, and behavioral symptoms. We intranasally administered either 1) intact, toxic Stachybotrys spores; 2) extracted, nontoxic Stachybotrys spores; or 3) saline vehicle to mice. As predicted, intact spores increased interleukin-1β immunoreactivity in the hippocampus. Both spore types decreased neurogenesis and caused striking contextual memory deficits in young mice, while decreasing pain thresholds and enhancing auditory-cued memory in older mice. Nontoxic spores also increased anxiety-like behavior. Levels of hippocampal immune activation correlated with decreased neurogenesis, contextual memory deficits, and/or enhanced auditory-cued fear memory. Innate-immune activation may explain how both toxic mold and nontoxic mold skeletal elements caused cognitive and emotional dysfunction.     

Effects of a synbiotic on symptoms,and daily functioning in attention deficit hyperactivity disorder – A double-blind randomized controlled trial

Some prebiotics and probiotics have been proposed to improve psychiatric symptoms in children with autism. However, few studies were placebo-controlled, and there is no study on persons with an attention deficit hyperactivity disorder (ADHD) diagnosis. Our aim was to study effects of Synbiotic 2000 on psychiatric symptoms and functioning in children and adults with ADHD without an autism diagnosis. Children and adults (n = 182) with an ADHD diagnosis completed the nine weeks randomized double-blind parallel placebo-controlled trial examining effects of Synbiotic 2000 on the primary endpoints ADHD symptoms, autism symptoms and daily functioning, and the secondary endpoint emotion regulation, measured using the questionnaires SNAP-IV, ASRS, WFIRS, SCQ, AQ and DERS-16. Levels at baseline of plasma C-reactive protein and soluble vascular cell adhesion molecule-1 (sVCAM-1), central to leukocyte-endothelial cell adhesion facilitating inflammatory responses in tissues, were measured using Meso Scale Discovery. Synbiotic 2000 and placebo improved ADHD symptoms equally well, and neither active treatment nor placebo had any statistically significant effect on functioning or sub-diagnostic autism symptoms. However, Synbiotic 2000, specifically, reduced sub-diagnostic autism symptoms in the domain restricted, repetitive and stereotyped behaviors in children, and improved emotion regulation in the domain of goal-directed behavior in adults. In children with elevated sVCAM-1 levels at baseline as well as in children without ADHD medication, Synbiotic 2000 reduced both the total score of autism symptoms, and the restricted, repetitive and stereotyped behaviors. In adults with elevated sVCAM-1 at baseline, Synbiotic 2000 significantly improved emotion regulation, both the total score and four of the five subdomains. To conclude, while no definite Synbiotic 2000-specific effect was detected, the analysis of those with elevated plasma sVCAM-1 levels proposed a reduction of autism symptoms in children and an improvement of emotion regulation in adults with ADHD.Trial registration number: ISRCTN57795429.     

Applying Health Belief Model to Unveil Employees’ Workplace COVID-19 Protective Behaviors: Insights for the Hospitality Industry

The overwhelming majority of the countries around the globe have witnessed severe cases of the COVID-19 outbreak. Unfortunately, many countries are still beset with such an infectious disease. Despite the fact that there is currently no specific approved cure for this deadly infection, restrictions (e.g., lockdown and border closing) are gradually eased. Meanwhile, businesses are reopening and outdoor leisure activities are about to start again based on strict health, social distancing, and hygiene rules. However, as we still have a long way to reach an ultimate treatment for such deadly virus, changing human behavior sounds the best defense in tackling this challenge till a vaccine is developed for protection against COVID-19. With this realization, using Health Belief Model as the theoretical underpinning, our study endeavors to unveil employees’ adherence to protective health behaviors (PHBs) in the hospitality industry, which is known as a people-focused, labor-intensive, and service-oriented business. This is so crucial since there is a high degree of (frequent) interaction between employees and customers in hotels. Moreover, such establishments are known as areas where customers engage in a variety of activities that make health concerns even more crucial. To achieve the objectives of this research, we used secondary data obtained from one of the largest hotel-related online communities in the world: the ‘Tales from the front desk’. Using template analysis approach, 1680 employees’ comments were examined. The results revealed that hotel employees found themselves at high risk of being infected and several obstacles that impeded their PHBs in the workplace were identified. Our study will provide momentous implications about PHBs against COVID-19 for the hospitality industry.