Biobehavioral Interactions Between Stress and Alcohol

Targeting corticotropin-releasing hormone receptor type 1 (Crhr1) neurons: validating the specificity of a novel transgenic Crhr1-FlpO mouse

Corticotropin-releasing hormone (CRH) signaling through its cognate receptors, CRHR1 and CRHR2, contributes to diverse stress-related functions in the mammalian brain. Whereas CRHR2 is predominantly expressed in choroid plexus and blood vessels, CRHR1 is abundantly expressed in neurons in discrete brain regions, including the neocortex, hippocampus and nucleus accumbens. Activation of CRHR1 influences motivated behaviors, emotional states, and learning and memory. However, it is unknown whether alterations in CRHR1 signaling contribute to aberrant motivated behaviors observed, for example, in stressful contexts. These questions require tools to manipulate CRHR1 selectively. Here we describe and validate a novel Crhr1-FlpO mouse. Using bacterial artificial chromosome (BAC) transgenesis, we engineered a transgenic mouse that expresses FlpO recombinase in CRHR1-expressing cells. We used two independent methods to assess the specificity of FlpO to CRHR1-expressing cells. First, we injected Crhr1-FlpO mice with Flp-dependent viruses expressing fluorescent reporter molecules. Additionally, we crossed the Crhr1-FlpO mouse with a transgenic Flp-dependent reporter mouse. CRHR1 and reporter molecules were identified using immunocytochemistry and visualized via confocal microscopy in several brain regions in which CRHR1 expression and function is established. Expression of Flp-dependent viral constructs was highly specific to CRHR1-expressing cells in all regions examined (over 90% co-localization). In accord, robust and specific expression of the Flp-dependent transgenic reporter was observed in a reporter mouse, recapitulating endogenous CRHR1 expression. The Crhr1-FlpO mouse enables selective genetic access to CRHR1-expressing cells within the mouse brain. When combined with Cre-lox or site-specific recombinases, the mouse facilitates intersectional manipulations of CRHR1-expressing neurons.

Moderating effects of smoking and drinking on the relationship between biological rhythm and psychological health and gender differences among adolescents

OBJECTIVES

To determine whether smoking and drinking moderate the correlation between biological rhythm and mental health and the role of gender differences in these moderating effects.

METHODS

Adolescents from three cities, all twelve middle schools (N = 7,986), named Shenzhen, Nanchang and Shenyang in China, were asked to complete a standardized questionnaire including the details of biological rhythm, psychological health, and the status of smoking and drinking. The PROCESS program was used to analyze whether smoking and drinking moderated the relationship between biological rhythm and psychological health.

RESULTS

The analyses revealed poorer psychological health and greater likelihood of smoking and drinking in participants with higher scores for biological rhythm disorder (P < 0.001). Specifically, smoking and drinking accelerated the relationship between biological rhythm and psychological health in the total sample (B = 0.05, P < 0.05; B = 0.06, P < 0.001) and only the subgroup of girls (B = 0.09, P < 0.05; B = 0.12, P < 0.001), respectively.

CONCLUSIONS

As the findings suggest, attention should be given to smoking, drinking and gender-specific approaches employed to alleviate the psychological disorders of adolescents with biological rhythm disorders.

Impact of Mephedrone on Fear Memory in Adolescent Rats: Involvement of Matrix Metalloproteinase-9 (MMP-9) and N-Methyl-D-aspartate (NMDA) Receptor

Treatment of Post-Traumatic Stress Disorder (PTSD) is complicated by the presence of drug use disorder comorbidity. Here, we examine whether conditioned fear (PTSD model) modifies the rewarding effect of mephedrone and if repeated mephedrone injections have impact on trauma-related behaviors (fear sensitization, extinction, and recall of the fear reaction). We also analyzed whether these trauma-induced changes were associated with exacerbation in metalloproteinase-9 (MMP-9) and the GluN2A and GluN2B subunits of N-methyl-D-aspartate (NMDA) glutamate receptor expression in such brain structures as the hippocampus and basolateral amygdala. Male adolescent rats underwent trauma exposure (1.5 mA footshock), followed 7 days later by a conditioned place preference training with mephedrone. Next, the post-conditioning test was performed. Fear sensitization, conditioned fear, anxiety-like behavior, extinction acquisition and relapse were then assessed to evaluate behavioral changes. MMP-9, GluN2A and GluN2B were subsequently measured. Trauma-exposed rats subjected to mephedrone treatment acquired a strong place preference and exhibited impairment in fear extinction and reinstatement. Mephedrone had no effect on trauma-induced MMP-9 level in the basolateral amygdala, but decreased it in the hippocampus. GluN2B expression was decreased in the hippocampus, but increased in the basolateral amygdala of mephedrone-treated stressed rats. These data suggest that the modification of the hippocampus and basolateral amygdala due to mephedrone use can induce fear memory impairment and drug seeking behavior in adolescent male rats.

The analysis of alcohol consumption during the severe acute respiratory syndrome Coronavirus 2 Italian lockdown

BACKGROUND

The SARS-CoV-2 lockdown resulted in deep changes of lifestyles, promoting in many people the onset of psychological symptoms generally associated with drug and alcohol abuse. The aim of this study was to assess the variation of alcohol drinking habits in a sample of Italian citizens during lockdown and to identify the psychosocial factors surrounding it.

METHODS

An online anonymous questionnaire was created and submitted from April 9 to April 28, 2020. Questions were related to personal psychosocial details and alcohol drinking habits during the lockdown, including Alcohol Use Disorders Identification Test (AUDIT C) questions.

RESULTS

On a total of 1234 surveys the increase of both anxiety and fear was largely detected (63% and 61% respectively). The 18% increased alcohol consumption during the lockdown and it showed a significant correlation with anxiety and fear experienced (both P<0.001). The relative risk for 7 to 9 and more than 10 drinks per day consumption were directly linked to these symptoms (P<0.001). The most involved categories of participants showed this harmful association were self-employed workers and participants who live alone, subject aged 30-50 with high level of instruction or students, and not occupied people in the age range 18-19 (all P<0.001). Additionally, the subset of the study population that showed low alcohol consumption before the lockdown has demonstrated the worsening of alcohol assumption during the quarantine (P<0.0001).

CONCLUSIONS

Several psychosocial factors are involved in determining the increase of alcohol consumption during lockdown and need the healthcare support to avoid awful impact on human life.

Effect of whole body cryotherapy on low back pain and release of endorphins and stress hormones in patients with lumbar spine osteoarthritis

Introduction

Low back pain (LBP) is the most common ailment in patients with lumbar spine osteoarthritis (OA). There are many methods to treat LBP, such as manual therapy, osteopathy, massage, physical exercise, and physical therapy. The most effective of these are manual therapy and exercises combined with physical procedures, such as whole body cryotherapy (WBCT). Whole body cryotherapy can induce various hormonal adaptations in patients with OA. This is probably the body’s reaction to cold and stress. The purpose of the study was to evaluate the impact of WBCT on β-endorphins, cortisol and adrenaline release, as well as on LBP in patients with OA of the lumbar spine.

Material and methods

The study group consisted of 30 patients with lumbar spine OA who underwent a series of WBCT combined with therapeutic exercises. Before and after the therapy each patient was examined using a visual analogue scale (VAS) and blood samples were collected for laboratory determinations (ELISA).

Results

After WBCT, the decrease in LBP measured by VAS was statistically significant (p < 0.0001). The mean value of blood β-endorphin level increased after the therapy but the difference was statistically insignificant (p = 0.10). The mean value of the plasma level of cortisol after treatment increased and the difference was statistically significant (p = 0.0009). The plasma level of adrenalin after treatment increased slightly, but the difference was statistically insignificant (p = 0.08).

Conclusions

Whole body cryotherapy combined with therapeutic exercises had a positive effect on LBP reduction in patients with OA. On the basis of these changes, processes that take place in the nervous and endocrine systems are a response to the stimuli of cold and stress. The mechanism of action of extremely low temperatures on the human body is still not fully understood.

Sex differences in stress-induced alcohol intake: a review of preclinical studies focused on amygdala and inflammatory pathways

Clinical studies suggest that women are more likely than men to relapse to alcohol drinking in response to stress; however, the mechanisms underlying this sex difference are not well understood. A number of preclinical behavioral models have been used to study stress-induced alcohol intake. Here, we review paradigms used to study effects of stress on alcohol intake in rodents, focusing on findings relevant to sex differences. To date, studies of sex differences in stress-induced alcohol drinking have been somewhat limited; however, there is evidence that amygdala-centered circuits contribute to effects of stress on alcohol seeking. In addition, we present an overview of inflammatory pathways leading to microglial activation that may contribute to alcohol-dependent behaviors. We propose that sex differences in neuronal function and inflammatory signaling in circuits centered on the amygdala are involved in sex-dependent effects on stress-induced alcohol seeking and suggest that this is an important area for future studies.

Voluntary alcohol binge-drinking in adolescent C57Bl6 mice induces delayed appearance of behavioural defects in both males and females

Adolescence is a developmental period characterized by significant changes in brain architecture and behaviour. The immaturity of the adolescent brain is associated with heightened vulnerability to exogenous agents, including alcohol. Alcohol is the most consumed drug among teenagers, and binge‐drinking during adolescence is a major public health concern. Studies have suggested that adolescent alcohol exposure may interfere with the maturation of frontal brain regions and lead to long‐lasting behavioural consequences. In this study, by using a slightly modified version of the Drinking in the Dark paradigm, adolescent C57Bl6 mice reach high blood alcohol concentration after voluntary binge‐drinking. In order to assess short‐ and long‐term consequences of adolescent alcohol exposure (AAE), a battery of behavioural tests was performed during late adolescence and during adulthood. We showed that AAE had no short‐term effect on young mice behaviour but rather increased anxiety‐ and depressive‐like behaviours, as well as alcohol consumption during adulthood. Moreover, alcohol binge‐drinking during adolescence dramatically decreased recognition memory performances and behavioural flexibility in both adult males and females. Furthermore, we showed that voluntary consumption of alcohol during adolescence did not trigger any major activation of the innate immune system in the prefrontal cortex. Together, our data suggest that voluntary alcohol binge‐drinking in adolescent mice induces a delayed appearance of behavioural impairments in adulthood.

Solitary Nitric Oxide Signaling Mediates Mild Stress-Induced Anxiety and Norepinephrine Release in the Bed Nucleus of the Stria Terminalis during Protracted Ethanol Withdrawal

Ethanol withdrawal (EtOHW) alters the pattern of neurohormonal and behavioral response toward internal and external stimuli, which mediates relapse to alcohol use even after a long period of abstinence. Increased noradrenergic signaling from the nucleus tractus solitarius (NTS) to the bed nucleus of the stria terminalis (BNST) during EtOHW underlies withdrawal-induced anxiety, while nitric oxide synthase (NOS) inhibitors injected into the periaqueductal area attenuate EtOHW-induced anxiety. Therefore, this study investigated the involvement of NOS within the NTS in anxiety and increased norepinephrine (NE) release in the BNST during protracted EtOHW in rats exposed to a mild stress. Rats were intraperitoneally administered 3 g/kg/day EtOH for 21 days followed by 28 days of withdrawal, and on the 28^th day of withdrawal, the rats were subjected to restraint stress for 7 minutes. The elevated plus maze test was employed to evaluate anxiety-like behavior in rats, and in vivo microdialysis was used to measure the extracellular NE level in the BNST. In elevated plus maze tests, EtOHW rats but not EtOH-naive rats exhibited anxiety-like behavior when challenged with 7-minute mild restraint stress, which was, respectively, mitigated by prior intra-NTS infusion of the nitric oxide scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO), nonselective NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME), or selective neuronal NOS (nNOS) inhibitor 7-nitroindazole (7-NI). Each of these agents also decreased the plasma corticosterone levels in EtOHW rats. In in vivo microdialysis, prior intra-NTS infusion of carboxy-PTIO, L-NAME, or 7-NI attenuated the mild stress-induced NE release in the BNST of EtOHW rats. Additionally, EtOHW rats showed increased solitary nNOS gene and protein expression. Moreover, the anxiolytic effect of intra-NTS administration of 7-NI was abolished by subsequent intra-NTS administration of sodium nitroprusside. These results suggest that elevation of solitary nitric oxide signaling derived from nNOS mediates stress-precipitated anxiety and norepinephrine release in the BNST during protracted EtOHW.

Repeated ethanol exposure following avoidance conditioning impairs avoidance extinction and modifies conditioning-associated prefrontal dendritic changes in a mouse model of post-traumatic stress disorder

Treatment of post-traumatic stress disorder is complicated by the presence of alcohol use disorder comorbidity. Little is known about the underlying brain mechanisms. We have recently shown, in mice, that the post-traumatic stress disorder-like phenotype is characterised by the increase and decrease in total dendritic number and length in the prelimbic and infralimbic areas of the medial prefrontal cortex, respectively. Here, we examined whether repeated ethanol exposure would exacerbate these changes and whether this would be associated with difficulty to extinguish passive avoidance behaviour, as an indicator of treatment resistance. We also analysed whether other known trauma-associated changes, like increased or decreased corticosterone and decreased brain-derived neurotrophic factor levels, would also be exacerbated. Male mice underwent trauma exposure (1.5-mA footshock), followed, 8 days later, by a conditioned place preference training with ethanol. Tests for fear sensitization, passive avoidance, anxiety-like behaviour, extinction acquisition and relapse susceptibility were used to assess behaviour changes. Plasma corticosterone and brain-derived neurotrophic factor levels and prefrontal dendritic changes were subsequently measured. Trauma-susceptible mice exposed to ethanol acquired a strong place preference and behaved differently from those not exposed to ethanol, with delayed avoidance extinction and higher avoidance relapse vulnerability. Ethanol potentiated trauma-associated dendritic changes in the prelimbic area and suppressed trauma-associated dendritic changes in the infralimbic area. However, ethanol had no effect on trauma-induced increased corticosterone and decreased brain-derived neurotrophic factor levels. These data suggest that the modification of prefrontal trauma-related changes, due to alcohol use, can characterise, and probably support, treatment-resistant post-traumatic stress disorder.

Determination of cortisol in hair using UHPLC-MS/MS: application to patients admitted for ethanol dependence treatment

Aim: Cortisol hair levels can be used to evaluate chronic stress status. In this context, an improved UHPLC-MS/MS assay for the determination of cortisol in hair was developed and validated. Materials & methods: Hair was extracted with methanol for 4 h at 25°C. Chromatographic run time was 5.5 min. The assay was linear in the range of 1-250 pg mg-1. Precision was 3.6-12.2% and accuracy 97.1-103.8%. The method was applied in hair from 19 volunteers admitted at a rehabilitation clinic, with ethanol consumption classified using ethyl glucuronide hair levels. Conclusion: Abstinent/chronic moderate ethanol consumers had significantly lower cortisol hair levels than chronic excessive consumers. This is the first study evaluating cortisol hair levels in ethanol abuse patients using an objective marker for ethanol consumption.

Telemedicine during the SARS-Cov-2 pandemic lockdown: Monitoring stress and quality of sleep in patients with epilepsy

SARS-CoV-2 pandemic heavily hit the western healthcare system saturating the hospital beds in wards and clogging the emergency departments. To avoid the collapse of Italian hospitals, office visits to outpatients were limited to emergencies and the general population went in a lockdown state. Physicians had to approach new problems in the management of chronic patients who could not leave their homes. In our experience as epilepsy clinic, the use of telemedicine was of crucial importance for monitoring our patients: phone call during lockdown let us monitor the stability of our 38 patients and psychometric parameters and habits that could influence seizures frequency. In particular, we found that in our patients, sleep quality was low resulting in high daily sleepiness and associated high stress levels. Secondly, we found an increase in daily screen hours and an association with daily sleepiness. In conclusion, we report our experience in managing people with epilepsy during the lockdown, underlining the utility of telemedicine as a valid monitoring tool and the necessity of a psychometric and behavioral screening.

Interaction of chronic intermittent ethanol and repeated stress on structural and functional plasticity in the mouse medial prefrontal cortex

Stress is a risk factor that plays a considerable role in the development and maintenance of alcohol (ethanol) abuse and relapse. Preclinical studies examining ethanol-stress interactions have demonstrated elevated ethanol drinking, cognitive deficits, and negative affective behaviors in mice. However, the neural adaptations in prefrontal cortical regions that drive these aberrant behaviors produced by ethanol-stress interactions are unknown. In this study, male C57BL/6J mice were exposed to chronic intermittent ethanol (CIE) and repeated forced swim stress (FSS). After two cycles of CIE x FSS, brain slices containing the prelimbic (PrL) and infralimbic (IfL) cortex were prepared for analysis of adaptations in dendritic spines and synaptic plasticity. In the PrL cortex, total spine density was increased in mice exposed to CIE. Immediately following induction of long-term potentiation (LTP), the fEPSP slope was increased in the PrL of CIE x FSS treated mice, indicative of a presynaptic adaptation on post-tetanic potentiation (PTP). In the IfL cortex, CIE exposure regardless of FSS experience resulted in an increase in spine density. FSS alone or when combined with CIE exposure increased PTP following LTP induction. Repeated FSS episodes increased IfL cortical paired-pulse facilitation, a second measure of presynaptic plasticity. In summary, CIE exposure resulted in structural adaptations while repeated stress exposure drove metaplastic changes in presynaptic function, demonstrating distinct morphological and functional changes in PrL and IfL cortical neurons. Thus, the structural and functional adaptations may be one mechanism underlying the development of excessive drinking and cognitive deficits associated with ethanol-stress interactions.

The Prevalence of Depression, Anxiety and Stress and Their Associated Factors in College Students

AIM

To estimate the prevalence of symptoms of depression, anxiety, stress and associated factors in a population of college students.

METHOD

Cross-sectional study of psychological distress measured through the Depression, Anxiety and Stress Scale (DASS-21) in a sample of 1074 college students.

RESULTS

We found a moderate prevalence of depression (18.4%), anxiety (23.6%) and stress (34.5%) symptoms in our study population. Being <21, having problematic Internet use behavior, smoking, presenting insomnia and having a low self-esteem were independently associated with symptoms of depression, anxiety and stress. Being a woman, living with their family, having a stable partner, consuming alcohol frequently and having poor nutritional habits were significantly associated with symptoms of stress; lacking a stable partner was significantly associated with depressive symptoms; and frequent consumption of alcohol was significantly associated with symptoms of anxiety.

CONCLUSION

We found a moderate prevalence of depression, anxiety and stress symptoms in our population. Interventions aimed at promoting mental health among college students should be implemented.

Bidirectional Control of Alcohol-drinking Behaviors Through Locus Coeruleus Optoactivation

The relationship between stress and alcohol-drinking behaviors has been intensively explored; however, neuronal substrates and neurotransmitter dynamics responsible for a causal link between these conditions are still unclear. Here, we optogenetically manipulated locus coeruleus (LC) norepinephrine (NE) activity by applying distinct stimulation protocols in order to explore how phasic and tonic NE release dynamics control alcohol-drinking behaviors. Our results clearly demonstrate contrasting behavioral consequences of LC-NE circuitry activation during low and high frequency stimulation. Specifically, applying tonic stimulation during a standard operant drinking session resulted in increased intake, while phasic stimulation decreased this measure. Furthermore, stimulation during extinction probe trials, when the lever press response was not reinforced, did not significantly alter alcohol-seeking behavior if a tonic pattern was applied. However, phasic stimulation substantially suppressed the number of lever presses, indicating decreased alcohol seeking under the same experimental condition. Given the well-established correlative link between stress and increased alcohol consumption, here we provide the first evidence that tonic LC-NE activity plays a causal role in stress-associated increases in drinking.

COVID-19 Confinement and Health Risk Behaviors in Spain

The World Health Organization (WHO) has declared a world pandemic due to COVID-19. In response, most affected countries have enacted measures involving compulsory confinement and restrictions on free movement, which likely influence citizens' lifestyles. This study investigates changes in health risk behaviors (HRBs) with duration of confinement. An online cross-sectional survey served to collect data about the Spanish adult population regarding health behaviors during the first 3 weeks of confinement. A large sample of participants (N = 2,741) (51.8% women; mean age 34.2 years [SD 13.0]) from all Spanish regions completed the survey. Binomial logistic regressions adjusted for socioeconomic characteristics (i.e., gender, age, civil status, education, and occupation), body mass index (BMI), previous HRBs, and confinement context (i.e., solitude and exposure to COVID-19) were conducted to investigate associations between the number of weeks confined and a set of six HRBs (physical activity, alcohol consumption, fresh fruit and vegetable consumption, smoking, screen exposure, and sleep hours). When adjusted, we observed significantly lower odds of experiencing a higher number of HRBs than before confinement overall in a time-dependent fashion: OR 0.63; 95% CI: 0.49-0.81 for the second and OR 0.47; 95% CI: 0.36-0.61 for the third week of confinement. These results were equally consistent in all age and gender subgroup analyses. The present study indicates that changes toward a higher number of HRBs than before confinement, as well as the prevalence of each HRB except screen exposure, decreased during the first 3 weeks of COVID-19 confinement, and thus the Spanish adult population may have adapted to the new situational context by gradually improving their health behaviors.