Circadian rhythmicity in schizophrenia male patients with and without substance use disorder comorbidity

Circadian rhythmicity is associated to clinical variables that play an important role in both schizophrenia (SZ) and substance use disorders (SUD), although the characteristics of the coexistence of these two diagnoses (SZ +) remain mostly unknown. Hence, we studied a sample of 165 male patients divided in three groups each of 55, according to their diagnoses (SZ + , SZ, and SUD), as well as a healthy control (HC; n = 90) group. Alongside with sociodemographic and clinical variables, circadian rhythms were registered through a sleep-wake data structured interview, a circadian typology questionnaire, and distal skin temperature (DST) using the Thermochron iButton every 2 min during 48 h. Analyses showed that SZ + and SZ patients presented a longer sleep (delay in wake-up time) and mostly an intermediate circadian typology, while SUD patients slept less hours, displaying a morning typology. The DST showed the highest daily activation and stability for the SUD group, even when compared with the HC group. The presence of schizophrenia (SZ + and SZ) was related to a DST pattern with a reduced amplitude determined by a wakefulness impairment, which was more pronounced for SZ patients whose sleep period was adequate. The assessment of circadian rhythms in under treatment male patients with SZ should be focused on the diurnal period as a possible marker of either treatment adherence or patient's recovery, irrespective of the presence of a comorbid SUD. Further research with additional objective measures may provide knowledge transferable to therapeutic strategies and could be useful to establish possible endophenotypes in the future.

The European intercomparison of in-vivo monitoring laboratories: the EIVIC-2020 project

The EIVIC project was launched in 2020, and the main goal was the organisation of a European intercomparison of in-vivo monitoring laboratories dealing with direct measurements of gamma-emitting radionuclides incorporated into the body of exposed workers. This project was organised jointly by members of EURADOS Working Group 7 on internal dosimetry (WG7), the Federal Office for Radiation Protection (BfS, Germany) and the Radioprotection and Nuclear Safety Institute (IRSN, France). The objective was to assess the implementation of individual-monitoring requirements in EU Member States on the basis of in-vivo measurements and to gain insight into the performance of in-vivo measurements using whole-body counters. In this context, a total of 41 in-vivo monitoring laboratories from 21 countries, together with JRC (EC) and IAEA participated. The results were submitted in terms of activity (Bq) of the radionuclides identified inside phantoms that were circulated to all participants. The measured data were compared with reference activity values to evaluate the corresponding bias according to the standards ISO 28218 and ISO 13528. In general, the results of the different exercises are good, and most facilities are in conformity with the criteria for the bias and z-scores in the ISO standards. Furthermore, information about technical and organisational characteristics of the participating laboratories was collected to test if they had a significant influence on the reported results.

Influence of light at night on allergic diseases: a systematic review and meta-analysis

BACKGROUND

Allergic diseases impose a significant global disease burden, however, the influence of light at night exposure on these diseases in humans has not been comprehensively assessed. We aimed to summarize available evidence considering the association between light at night exposure and major allergic diseases through a systematic review and meta-analysis.

METHODS

We completed a search of six databases, two registries, and Google Scholar from inception until December 15, 2023, and included studies that investigated the influence of artificial light at night (ALAN, high vs. low exposure), chronotype (evening vs. morning chronotype), or shift work (night vs. day shift work) on allergic disease outcomes (asthma, allergic rhinitis, and skin allergies). We performed inverse-variance random-effects meta-analyses to examine the association between the exposures (ALAN exposure, chronotype, or shiftwork) and these allergic outcomes. Stratification analyses were conducted by exposure type, disease type, participant age, and geographical location along with sensitivity analyses to assess publication bias.

RESULTS

We included 12 publications in our review. We found that exposure to light at night was associated with higher odds of allergic diseases, with the strongest association observed for ALAN exposure (OR: 1.88; 95% CI: 1.04 to 3.39), followed by evening chronotype (OR: 1.35; 95% CI: 0.98 to 1.87) and exposure to night shift work (OR: 1.33; 95% CI: 1.06 to 1.67). When analyses were stratified by disease types, light at night exposure was significantly associated with asthma (OR: 1.62; 95% CI: 1.19 to 2.20), allergic rhinitis (OR: 1.89; 95% CI: 1.60 to 2.24), and skin allergies (OR: 1.11; 95% CI: 1.09 to 1.91). We also found that the association between light at night exposure and allergic diseases was more profound in youth (OR: 1.63; 95% CI: 1.07 to 2.48) than adults (OR: 1.30; 95% CI: 1.03 to 1.63). Additionally, we observed significant geographical variations in the association between light at night exposure and allergic diseases.

CONCLUSIONS

Light at night exposure was associated with a higher prevalence of allergic diseases, both in youth and adults. More long-term epidemiological and mechanistic research is required to understand the possible interactions between light at night and allergic diseases.

Neuropsychological functioning of patients with major depression or bipolar disorder comorbid to substance use disorders: A systematic review

Major depression disorder (MDD) and bipolar disorder (BD) are usual comorbidities in patients with substance use disorders (SUD), a condition known as dual disorder (DD). MDD, BD and SUD are associated with cognitive impairment, potentially leading to a greater functional impairment in the context of DD.

OBJECTIVES

To review the existing data on the cognitive impairment in DD patients with comorbid MDD or BD, considering the influence of the depressive symptomatology.

METHODS

Following the PRISMA protocol 19 studies were selected from the last 17 years, 13 of which focused on BD, five on MDD and one included both diagnoses.

RESULTS

Studies based in BD+SUD showed that the most affected cognitive domains were attention and executive functions, but not all of them found a greater impairment due to the comorbidity. While fewer studies were found for depression, MDD+SUD works point to a similar impairment cognitive pattern. Furthermore, depression improvement could be associated to better cognitive performance.

LIMITATIONS

More standardized research is needed regarding the influence of depression on cognitive performance of DD patients, especially on those with comorbid MDD. Factors such as main substance, abstinence, or MDD/BD-related variables should be considered. Unstudied factors, like gender or circadian rhythms, are proposed to improve knowledge in this area.

CONCLUSIONS

Current studies suggest that DD could potentiate cognitive impairment in BD, MDD and SUD. However, additional research is needed to improve the understanding of comorbidity to apply more individualized therapies in the treatment of these patients, considering the interference of their neurocognitive functioning.

Patients with Schizophrenia Showed Worse Cognitive Performance than Bipolar and Major Depressive Disorder in a Sample with Comorbid Substance Use Disorders

Comorbidity of substance use disorders (SUD) and severe mental illness (SMI) is highly frequent in patients, the most common diagnoses being schizophrenia (SZ), bipolar disorder (BD) and major depressive disorder (MDD). Since comorbidity has its own clinical features, and neurocognitive functioning is not always similar to psychiatric symptoms the present study explores the cognitive performance of patients with dual disorders. A neuropsychological battery of tests was used to assess 120 under treatment male patients, 40 for each group considered (SZ + SUD, BD + SUD and MDD + SUD) who were mainly polyconsumers. Significant differences (with premorbid IQ as a covariate) were found among the groups, with SZ + SUD having a worse performance in attention, verbal learning, short term memory and recognition. The consideration of a global Z score for performance evidenced an impaired neurocognitive pattern for SZ + SUD compared with BD + SUD and MDD + SUD. According to norms, all patients showed difficulties in verbal learning, short-term memory and recognition. Our research indicated that the neurocognitive functioning of dual disorder patients was influenced by the comorbid SMI, with SZ + SUD presenting major difficulties. Future studies should thoroughly explore the role of such difficulties as indicators or endophenotypes for dual schizophrenia disorders, and their usefulness for prevention and treatment.

Premorbid functioning in schizophrenia spectrum disorders with comorbid substance use: A systematic review

Premorbid functioning has been related with several clinical features and prognosis of schizophrenia spectrum disorders. Comorbidity with substance use is highly prevalent and usually hinders clinical improvement in this kind of psychiatric disorders. This systematic review analyzes the differences in the premorbid functioning of subjects with a schizophrenia spectrum disorder with substance use (SSD+, dual psychosis) or without it (SSD-). A systematic review (PRISMA guidelines), including search in electronic databases (MEDLINE, Web of Science, and Cochrane Library), was performed. 118 published works were considered of which only 20 met our inclusion criteria. Although there is a great variability in methodologies, diagnoses included, and substances used, studies using the Premorbid Functioning Scale to assess the academic and/or social domains found that SSD+ subjects had a poorer academic but better social premorbid functioning than those with SSD-. Current evidence is not conclusive, so additional studies are required to integrate intervening factors in order to clarify the clinical implications of premorbid functioning to improve the course and therapeutic response of patients.

Circadian Functioning and Quality of Life in Substance Use Disorder Patients With and Without Comorbid Major Depressive Disorder

Aim: Although a relationship between circadian disruption and development of several psychiatric disorders, such as major depressive disorder (MDD) and substance use disorder (SUD), has been observed, knowledge on this area is scarce yet. Therefore, this study aims to analyze the circadian functioning and quality of life (QOL) in SUD patients with and without comorbid MDD, two highly prevalent clinical entities with difficult therapeutic management. Methods: One hundred sixty-three male patients under treatment, 81 with SUD and 82 with SUD comorbid major depressive disorder (SUD + MDD), were evaluated. For the circadian functioning assessment, we calculated Social Jet Lag (SJL) and used the reduced Morningness-Eveningness Questionnaire (rMEQ) and the Pittsburgh Sleep Quality Index (PSQI). QOL was measured using the shortened version of the World Health Organization's Quality of Life Questionnaire (WHOQOL-BREF). We collected sociodemographic and clinical variables to evaluate their possible influence on the circadian functioning. Intergroup differences among the variables were examined by different analyses of covariance (ANCOVA and MANCOVA). The possible relationships of quantitative clinical variables with rMEQ, PSQI, and WHOQOL-BREF were explored using bivariate correlation analysis. Results: Lower SJL appears in the SUD + MDD group compared with SUD. The intermediate-type was more prevalent in the SUD group, while a higher percentage of morning-type patients was found in the SUD + MDD. Sleep quality (including latency and daytime dysfunction) was worse for SUD + MDD patients than for SUD even after controlling age and age of SUD onset variables. Last, QOL was poorer in patients with SUD + MDD and, for them, psychological health had a negative relationship with SJL and severity of depression. Conclusions: Our data support and extend previous findings indicating that SUD + MDD is associated with worse clinical characteristics, more sleep problems, and poorer QOL than SUD patients. These results underline the importance of a precise assessment of these measurements in future studies conducted in SUD patients with/without MDD comorbidity that could be considered from a therapeutic point of view.

Health-Related Quality of Life in Male Patients under Treatment for Substance Use Disorders with and without Major Depressive Disorder: Influence in Clinical Course at One-Year Follow-Up

Health-related quality of life (HRQoL) assessment has interest as an indicator of degree of affectation and prognosis in mental disorders. HRQoL is impaired in both Substance Use Disorder (SUD) and Major Depressive Disorder (MDD), two conditions highly prevalent, although less studied when both are coexisting (SUD + MDD). Hence, we decided to explore HRQoL with the SF-36 survey in a sample of 123 SUD and 114 SUD + MDD patients (51 symptomatic and 63 asymptomatic of depressive symptoms) under treatment. We performed analyses to examine HRQoL among groups, and its predictive value at 3-, 6- and 12-month follow-ups through regression models. Patients with SUD + MDD had worse HRQoL than SUD patients and population norms. For Mental Health, Vitality, and General Health dimensions, lower scores were observed for SUD + MDD regardless the presence/absence of depressive symptoms. For Physical Functioning and Health Change, depressive symptomatology and not the comorbidity of SUD + MDD diagnoses explained HRQoL limitations. At 3-, 6- and 12-month follow-ups we observed two predictors of relapses, General Health for asymptomatic SUD + MDD, and Physical Functioning for SUD. Improving HRQoL in SUD + MDD may be targeted during patient's treatment; future studies should explore the influence of HRQoL on patient's prognosis taking into account the presence/absence of depressive symptomatology.

The Influence of Placebo Effect on Craving and Cognitive Performance in Alcohol, Caffeine, or Nicotine Consumers: A Systematic Review

OBJECTIVE

The present systematic review aims to analyze the evidence about the influence of placebo effect on craving and cognitive performance in alcohol, caffeine, and nicotine consumers.

METHODS

Relevant studies were identified via Pubmed, Web of Science, and Scopus databases (up to March 2020). Only those papers published between 2009 and 2019 were searched.

RESULTS

Of the 115 preliminary papers, 8 studies of database search and 9 of the manual search were finally included in this review. Findings showed that while alcohol expectancies increased craving, caffeine and nicotine expectancies tend to decrease it. Alcohol expectancies caused similar or slower reaction time when alcohol was not consumed, impairments on inhibitory control (especially after alcohol consumption) and similar post-error slowing. The effect of caffeine and nicotine on reaction time has not been elucidated yet, however, caffeine expectancies have been shown to improve accuracy and the attentional filtering of distracting stimuli.

CONCLUSIONS

Alcohol, caffeine, and nicotine expectancies play an important role on craving. Although expectancies produce an effect on cognitive performance, caffeine and nicotine beliefs show an ambiguous impact on reaction time. Only the influence of alcohol expectancies on reaction time has been clarified. Furthermore, caffeine beliefs enhance accuracy.

METHODOLOGY AT CIEMAT WHOLE BODY COUNTER FOR IN VIVO MONITORING OF RADIOIODINE IN THE THYROID OF EXPOSED POPULATION IN CASE OF NUCLEAR EMERGENCY

Iodine-131 is one of the main concerns from the point of view of radiological protection in a short term after a nuclear accident. The WBC Laboratory of CIEMAT has developed a methodology for in vivo monitoring of radioiodine in the thyroid of exposed individuals in case of emergency. Thyroid-neck phantoms of different sizes are required for calibrating the detection systems in appropriate counting geometries for the measurement of exposed population. A Low-Energy Germanium (LEGe) detector and a Fastscan Counter were calibrated using a set of thyroid phantoms fabricated by CIEMAT. Each neck phantom consists of a Lucite cylinder with a vial source of 131I. Counting efficiencies depending on age and thyroid sizes were obtained to be used to determine the activity of 131I in internally contaminated people. DL of 131I varies with the age, being in the range of 5-8 Bq for the LEGe detector and 26-42 Bq for the Fastscan. Detection of intakes resulting in Committed Effective doses far below 1 mSv are guaranteed for thyroid monitoring in a few days after the accidental exposure assuming a scenario of acute inhalation or ingestion of 131I by members of the public.

Effects of para-methoxyamphetamine (PMA) on agonistic encounters between male mice

Para-methoxyamphetamine (PMA) is a synthetic drug chemically similar to the recreational drug 3,4-methylenedioxy-methamphetamine (MDMA or "ecstasy") and often replaces MDMA in tablets that show an "ecstasy" logo. PMA displays a higher toxic potential than MDMA, but the behavioral profile of PMA has been scarcely studied in animal models. Here we evaluated the effects of PMA (2, 4, 8, and 12 mg/kg, i.p.) on agonist encounters between male mice using an ethopharmacological approach, the isolation-induced aggression model. Likewise, since PMA and MDMA share common mechanisms of action, we compared the behavioral profile of PMA with that induced by MDMA (8 mg/kg, i.p.) which behavioral effects in this model are well characterized. Individually housed mice were exposed to anosmic standard opponents 30 min after drug administration. The encounters were videotaped and evaluated using an ethologically based analysis. PMA (all doses) significantly reduced offensive behaviors (threat and attack), however, a detailed behavioral analysis suggests that the observed antiaggressive effect seems to be unspecific, showing a complex dose-dependent behavioral profile. Thus, antiaggresive actions observed after the administration of the lowest dose were accompanied by increases in social investigation, avoidance/flee behaviors and non-social explorations, together with a reduction of digging behavior. This pattern reflects both approach-contact behaviors and avoidance-flee behaviors. From 4 mg/kg to 12 mg/kg, the increase in social investigation previously observed disappears, and there is a slight increase in immobility, together with a different behavioral pattern that suggests anxiogenic effects of PMA, similar to those reported after the administration of MDMA. The higher doses of PMA exhibit a behavioral profile very similar to that observed in animals treated with MDMA, with the exception of the immobility produced by PMA. These findings show for the first time the non-specific antiaggressive profile of PMA in the model of aggression induced by isolation in male mice.

Personality Profile and Clinical Correlates of Patients With Substance Use Disorder With and Without Comorbid Depression Under Treatment

Background: Among patients with substance use disorder (SUD), major depressive disorder (MDD) is highly prevalent. Even though, personality plays an important role in treatment outcomes for individuals with SUD and SUD + MDD, few studies have explored personality characteristics in these samples. This study aims to describe personality for patients with SUD taking into account the comorbid MDD, using the Alternative Five Factor Model (AFFM). We also aim to compare SUD + MDD patients with population norms and to elucidate possible personality clinical correlates. Methods: For our study, 116 male patients undergoing for SUD treatment were divided in two groups: SUD only (N = 58) and SUD + MDD (N = 58). To examine personality, we used the Zuckerman-Kuhlman Personality Questionnaire and multiple analyses of covariance were performed to identify differences. In a first analysis, age was introduced as a covariate whereas in a second analysis the continuous variables that showed to have a discriminant value for the groups were added as covariates. Variables predicting the presence of dual diagnosis and personality clinical correlates were analyzed by logistic and linear regression models, respectively. We observed that patients with SUD + MDD show distinctive personality characteristics compared with patients with SUD only and population norms. Results: According to the AFFM, SUD + MDD patients are characterized by higher Neuroticism-Anxiety (positively associated to depressive symptoms) and Impulsivity; and by lower Parties and Friends. Moreover, the probability of having a dual depressive disorder was represented by the amount of medications and substances used. The preference for hard work and the energy self-reported levels (Work Activity trait) are linked to these clinical variables rather than to the presence/absence of a dual depressive disorder. Conclusions: Even when controlling clinical variables related to a higher probability of having a dual depressive disorder, the Neuroticism-Anxiety is a personality trait that strongly differentiates between SUD only and SUD + MDD patients. Further investigation is needed to explore the role of this personality trait as endophenotype in dual depressive men. Our results underline the importance of a dimensional understanding of personality and its clinical correlates among patients with SUD + MDD; this approach could provide us information on specific treatment strategies to improve the prognosis of patients.

Coping strategies related to treatment in substance use disorder patients with and without comorbid depression

Coping strategies exert an important influence in the development and course of both substance use disorder (SUD) and major depressive disorder (MDD) and its treatment outcomes. We examined the coping strategies related to treatment in SUD and SUD-MDD patients and their associations with clinical characteristics. Forty SUD and 40 SUD-MDD males, each group composed by 20 therapeutic community and 20 ambulatory treatment patients, were assessed through the Coping Strategies Inventory and clinical characteristics questionnaires. SUD-MDD patients scored higher in Disengagement strategies such as Social Withdrawal and lower in Engagement ones such as Problem Solving, Cognitive Restructuring and Social Support, as well as in self-perceived capacity for coping. No differences for treatment were found. SUD and, specially, SUD-MDD patients scored higher than norms in maladaptive strategies. Time of abstinence, age of onset and severity of SUD were related to maladaptive coping. SUD and SUD-MDD patients are prone to employ Disengagement coping strategies and SUD-MDD patients coping repertory is more maladaptive than the SUD ones. Likewise, clinical characteristics associated to maladaptive coping might differ by diagnosis and modality of treatment in male patients. These findings could be considered for the treatment design and to improve the recovery and prevent relapses.

Neurobiological underpinnings and modulating factors in schizophrenia spectrum disorders with a comorbid substance use disorder: A systematic review

Recently there is a growing interest in the interaction of schizophrenia spectrum disorders (SSD) and substance use disorders (SUD), a condition named dual schizophrenia spectrum disorders (SSD+). While previous research has focused on clinical and cognitive aspects, little is known about the impact of comorbidity in the brain structure and functions. Evidence suggests that dual diagnosis patients, including SSD+, show a better neurocognitive functioning during the first years of illness, followed by a serious long-term decline. The initial search retrieved 94 articles, 12 were excluded for being redundant and 49 for not fulfilling the selection criteria. Thirty-three structural and functional neuroimaging studies that compare SSD and SSD+ patients were included. Both groups exhibited more brain alterations, in comparison to only SUD patients and healthy controls. SSD+ patients are less cognitively and emotionally impaired than non-dual SSD, but worse than healthy controls. The neurobiological alterations are prominent in SSD+ after five years of illness or longer. Moreover, SUD characteristics are important modulating factors, contrary to clinical severity or specific SSD diagnosis.

Executive Functioning in Men with Schizophrenia and Substance Use Disorders. Influence of Lifetime Suicide Attempts

Background

Lifetime suicide attempts in patients with comorbidity between psychotic disorders and Substance Use Disorder (SUD), known as dual diagnosis, was associated with a worse clinical and cognitive state, poor prognosis and premature death. However, to date no previous study has examined the cognitive performance of these patients considering as independent the presence or absence of lifetime suicide attempts.

Methods

We explore executive functioning differences between suicide attempters and non-attempters in dual schizophrenia (DS) patients and the possible related factors for both executive performance and current suicide risk. Fifty DS male patients in remission of SUD and clinically stables, 24 with and 26 without lifetime suicide attempts, were evaluated. We considered Z scores for all neuropsychological tests and a composite summary score for both premorbid IQ and executive functioning.

Results

DS patients showed low performance in set-shifting, planning and problem solving tasks. Those with suicide attempts presented lower composite summary scores, together with worse problem solving skills and decision-making, compared with non-attempters. However, after controlling for alcohol dependence, only differences in decision-making remained. Executive functioning was related to the premorbid intelligence quotient, and several clinical variables (duration, severity, months of abstinence and relapses of SUD, global functioning and negative symptoms). A relationship between current suicide risk, and first-degree relatives with SUD, insight and positive symptoms was also found.

Conclusions

Our results suggest that problem solving and, especially, decision-making tasks might be sensitive to cognitive impairment of DS patients related to presence of lifetime suicide attempts. The assessment of these executive functions and cognitive remediation therapy when necessary could be beneficial for the effectiveness of treatment in patients with DS. However, further research is needed to expand our findings and overcome some limitations of this study.

Personality Traits Related to Binge Drinking: A Systematic Review

The pattern of alcohol consumption in the form of binge drinking (BD) or heavy episodic drinking has increased notably worldwide in recent years, especially among adolescent and young people, being currently recognized as a global health problem. Although only a minority of binge drinkers will develop a substance use disorder, BD may have negative personal and social consequences in the short and medium term. The objective of this article is to review the findings on personality traits related to binge drinkers and to emphasize the aspects that should be examined in order to make progress in this area. The main characteristics of personality related to the practice of BD, regardless of the theoretical model used, are high Impulsivity and high Sensation seeking, as well as Anxiety sensitivity, Neuroticism (Hopelessness), Extraversion and low Conscientiousness. The data obtained may have theoretical implications to elucidate the endophenotype of BD, but they are especially useful for their preventive applications. Integration into prevention programs of emotional self-control skills, decision-making, social skills, and strategies to manage negative emotions will minimize the risk factors or consequences of BD associated with personality and will improve their effectiveness. In the future, it is necessary to harmonize a common measurement instrument for the assessment of personality, develop longitudinal studies with large samples that also integrate biological and neurocognitive measurements, and determine the reciprocal relationship between personality and BD together with its modulating variables, as well as the possible cultural differences.

Circadian rhythmicity in substance use disorder male patients with and without comorbid depression under ambulatory and therapeutic community treatment

Although there have been described alterations of circadian rhythmicity both in patients with substance use disorder (SUD) and patients with major depressive disorder (MDD), the circadian characteristics of SUD patients with comorbid MDD (SUD-MDD) are unknown. Likewise, the possible influence of the different modalities of treatments (ambulatory or therapeutic community) upon the circadian rhythmicity of SUD patients has not been characterized. Therefore, this study analyzes the circadian rhythmic profiles of SUD and SUD-MDD patients under ambulatory and therapeutic community treatment. The sample was composed of 40 SUD and 40 SUD-MDD men, aged 22-55 yrs, under treatment and with abstinence for at least three months (including each group 20 ambulatory and 20 from therapeutic community). Patients completed a sociodemographic, clinical and sleep-wake schedules interview, the Composite Scale of Morningness, and wore on the wrist an ambulatory device known as iButton® Thermochron DS1921H, which registered their distal skin temperature every two minutes for 48 hours. All the groups showed a tendency to morningness without differences among them in concordance with their sleep-wake schedules. With regard to distal skin temperature circadian rhythm, SUD patients showed higher values than SUD-MDD in amplitude, relative amplitude, percentage rhythm, and first harmonic power, and lower minimum temperature in 10 consecutive hours (p < .043, in all cases). Therapeutic community group values were lower in minimum temperature and higher in amplitude, relative amplitude, and 12 harmonic accumulated power (p < .028, in all cases) as compared to ambulatory ones. Moreover, all groups showed higher Rayleigh vector and rhythm stability as compared to normative population (p < .043, in both cases). The circadian rhythmic differences observed for diagnosis and type of treatment are indicative of a higher circadian rhythmicity robustness in SUD and therapeutic community patients as compared to SUD-MDD and ambulatory ones, respectively. Although drug consumption exerts a negative effect on the circadian rhythmicity, our results (high amplitude and rhythm stability) are indicative of an adequate circadian functioning as well as of an adjustment to the light-dark cycle in both diagnosis and type of treatment which may constitute a marker of the adherence to treatment and recovery status.

THE CHALLENGE OF CIEMAT INTERNAL DOSIMETRY SERVICE FOR ACCREDITATION ACCORDING TO ISO/IEC 17025 STANDARD, FOR IN VIVO AND IN VITRO MONITORING AND DOSE ASSESSMENT OF INTERNAL EXPOSURES

The accreditation of an Internal Dosimetry Service (IDS) according to ISO/IEC 17025 Standard is a challenge. The aim of this process is to guarantee the technical competence for the monitoring of radionuclides incorporated in the body and for the evaluation of the associated committed effective dose E(50). This publication describes the main accreditation issues addressed by CIEMAT IDS regarding all the procedures involving good practice in internal dosimetry, focussing in the difficulties to ensure the traceability in the whole process, the appropriate calculation of detection limit of measurement techniques, the validation of methods (monitoring and dose assessments), the description of all the uncertainty sources and the interpretation of monitoring data to evaluate the intake and the committed effective dose.

EFFICIENCY STUDY OF A LEGe DETECTOR SYSTEM FOR THE ASSESSMENT OF 241Am IN SKULL AT CIEMAT WHOLE BODY COUNTER

(241)Am incorporation due to an incident or chronic exposure causes an internal dose, which can be evaluated from the total activity of this isotope in the skeleton several months after the intake. For this purpose, it is necessary to perform in vivo measurements of this bone-seeker radionuclide in appropriate counting bone geometries with very low attenuation of surrounded tissue and to extrapolate to total activity in the skeleton (ICRP 89, Basic anatomical and physiological data for use in radiological protection: reference values. 2001. 265). The work here presented refers to direct measurements of americium in the Cohen skull phantom at the CIEMAT Whole Body Counter (WBC) using low-energy germanium (LEGe) detectors inside a shielding room. The main goal was to determinate the most adequate head counting geometry for the in vivo detection of americium in the bone. The calibration of the in vivo LEGe system was performed with four detectors with 2 cm of distance to Cohen phantom. Two geometries were measured, on junction of frontal to parietal bones and frontal bone. The efficiencies are very similar in both geometries, the preferred counting geometry is the most comfortable for the person, with the LEGe detectors in the highest part of the frontal bone, near the junction with the parietal bone, CIEMAT WBC participated in a skull intercomparison exercise organised by WG7 of EURADOS (European Radiation Dosimetry Group e.V.). Efficiencies using three different skull phantoms were obtained. Measurements were performed for different head counting positions, four of them in the plane of symmetry and others over the temporal bone. The detector was placed in parallel with the calibration phantom at a distance of 1 cm. The main gamma emission of (241)Am, 59.5 keV (36 %), was used for comparing efficiency values. The lower efficiency was obtained over the frontal and occipital bones. Measurement with one LEGe detector over the parietal bone is the most efficient. The activity of each skull phantom was calculated using CIEMAT head calibration. Results of the EURADOS intercomparison are presented here for discussion.

Estudio de la instigación social en un modelo de agresión inducida por aislamiento: efectos de la administración de JNJ16259685, un antagonista de receptores mGlu1

La instigación social intensifica la conducta agresiva permitiendo observar niveles más extremos de agresión. Estudios recientes indican que el receptor metabotrópico del glutamato mGlu1 está implicado en la regulación de la conducta agresiva en un modelo de agresión inducida por aislamiento. El objetivo de este trabajo fue evaluar los efectos de la administración de un antagonista del receptor mGlu1 (JNJ16259685) sobre la conducta agresiva normal e intensificada utilizando instigación social en un modelo animal de agresión inducida por aislamiento. Varios grupos de animales aislados fueron expuestos a 5 minutos de instigación social, recibiendo la mitad de ellos JNJ16259685 (0.5 mg/kg, ip) o vehículo. Las interacciones agonísticas de 10 min de duración se realizaron en un área neutral 30 min después de la inyección. Dichos encuentros fueron grabados en vídeo para el posterior análisis etológico de diez categorías conductuales. La instigación redujo la latencia de ataque, y aumentó la frecuencia y duración de los ataques frente a los animales no instigados. La administración de JNJ16259685 redujo de forma significativa la conducta agresiva en ambos casos, sugiriendo la implicación del receptor mGlu1 en la modulación de la agresión normal e intensificada.

Effects of MPEP, a selective metabotropic glutamate mGlu5 ligand, on sleep and wakefulness in the rat

Metabotropic glutamate receptors (mGlu) have been implicated in the regulation of physiological and behavioral processes. Pharmacological evidence involves group I mGlu receptors in the regulation of emotional states and antagonism of these receptors has been proposed as a novel class of anxiolytic drugs having also antidepressant effects. Here, the effects of mGlu5 receptor selective modulation on sleep and wake states are explored. 32 male Wistar rats were implanted with electrodes for recording sleep and wake states. 2-Methyl-6-(phenylethynyl)pyridine hydrochloride (MPEP hydrochloride, 5, 10, and 20 mg/kg, i.p.), a potent, selective and systemically active mGlu5 receptor negative allosteric modulator, or vehicle was administered 1 h after the beginning of the light period. Sleep recordings were conducted for 3 h. MPEP (5, 10, and 20 mg/kg) significantly suppressed rapid eye movement (REM) sleep, decreasing the number of episodes and mean episode duration, and increased its latency. A reduction of light and deep slow wave sleep (SWS) latency was observed in the groups receiving 10 or 20 mg/kg, increasing latency to first wakefulness episode. 10 mg/kg of MPEP also increased non rapid eye movement sleep (NREM). The present results suggest that mGlu5 receptors might be involved in sleep regulation, more specifically in REM sleep, and drugs that block these receptors could potentially benefit the treatment of pathologies were REM sleep is enhanced.

Effects of (+) SKF 10,047, a sigma-1 receptor agonist, on anxiety,tested in two laboratory models in mice

Recently, sigma-1 receptor modulators have been considered drugs with an interesting therapeutic potential for the treatment of anxiety. However, there is no clear information in preclinical studies about the possible effects of sigma-1 ligands on anxiety in experimental animal models. Therefore, the present study examined the effects of (+)SKF 10,047 (2-8 mg/kg, ip), a sigma-1 agonist, on anxiety, tested in two classical laboratory models (social interaction test and elevated plus maze). (+)SKF 10,047 (8 mg/kg) produced a significant decrease of social investigation in the "social interaction test", whereas in the "elevated plus maze", the drug (4 and 8 mg/kg) provoked a significant reduction in the number of entries into open arms, as well as in the time spent in this area, as compared with the control group, without affecting motor activity. Overall, these findings indicate that (+)SKF 10,047 exhibits an anxiogenic-like profile in mice. It is suggested that anxiogenic effects of this sigma-1 ligand could be related to its potent ability to modulate diverse neurotransmitter systems involved in anxiety regulation.

EURADOS intercomparison on measurements and Monte Carlo modelling for the assessment of americium in a USTUR leg phantom

A collaboration of the EURADOS working group on 'Internal Dosimetry' and the United States Transuranium and Uranium Registries (USTUR) has taken place to carry out an intercomparison on measurements and Monte Carlo modelling determining americium deposited in the bone of a USTUR leg phantom. Preliminary results and conclusions of this intercomparison exercise are presented here.

Effects of (RS)-3,4-DCPG, a mixed AMPA antagonist/mGluR8 agonist, on aggressive behavior in mice

INTRODUCTION

Ionotropic and metabotropic (mGlu) receptors of glutamate have been suggested to be involved in the modulation of aggression. Thus, recent studies found reduced aggression in AMPA-type glutamate receptor GluR-A subunit-deficient mice. Likewise, mGlu1 and 5 receptors have also been implicated in aggression regulation. (RS)-3,4-DCPG is a mixed antagonist of AMPA receptors and an agonist of mGluR8. The AMPA antagonist activity of this compound is determined by its R isomer while the S isomer is responsible for its mGluR8 agonistic properties.

METHODS

We analyzed the effects of (RS)-3,4-DCPG (5, 10 and 20mg/kg, ip) on agonistic encounters between male mice. Individually housed mice were exposed to anosmic opponents 30 min after drug administration. Ten min of dyadic interactions were staged between a singly housed and an anosmic mouse in a neutral area. The encounters were videotaped and the accumulated time allocated by subjects to 10 broad behavioral categories was estimated using an ethologically based analysis.

RESULTS AND CONCLUSIONS

The results indicated that (RS)-3,4-DCPG produced no significant behavioral changes, suggesting that antagonism of AMPA receptors by the R isomer and stimulation of mGluR8 by the S isomer do not act synergistically on aggression in the racemic form of 3,4-DCPG.

Behavioural profile of selective ligands for mGlu7 and mGlu8 glutamate receptors in agonistic encounters between mice

Evidence is accumulating for a role of glutamate transmission in aggression modulation. Recent studies indicate that glutamate metabotropic receptors (mGlu1 and mGlu5) are involved in the regulation of aggressive behaviour. However, to date, the possible role of mGlu7 and mGlu8 receptors has not been explored. In this work, we analyze the effect of acute administration of AMN082 (0.5-4 mg/kg, ip) and (S)-3,4-DCPG (2.5-10 mg/kg, ip), selective ligands for the mGlu7 and mGlu8 receptors, respectively, on agonistic encounters between male mice. Individually housed mice were exposed to anosmic opponents 60 or 30 min after drug administration. Ten min of dyadic interactions were staged between a singly housed and an anosmic mouse in a neutral area. The encounters were videotaped and the accumulated time allocated by subjects to ten broad behavioural categories was estimated using an ethologically based analysis. The highest dose of AMN082 (4 mg/kg) significantly reduced offensive behaviours (threat and attack), as compared with the control group, without depressing motility, whereas (S)-3,4-DCPG did not produce significant behavioural changes. Overall, these results suggest that mGlu7 receptors (but not mGlu8) may be implicated in the modulation of aggression.

Effects of LY379268, A Selective Agonist of mGLu2/3 Receptors, on Isolation-Induced Aggression in Male Mice

Recent studies indicate that glutamate metabotropic receptors (mGlu) 1 and 5 are involved in the regulation of aggressive behaviour. Brain distribution of mGlu2/3 receptors suggests that they may also play important roles in emotional responses, including aggression. This study examines the effects of LY379268 (0.25- 4 mg/kg, ip), a selective agonist of the mGlu2/3 receptors, on agonistic interactions between male mice using an animal model of isolation-induced aggression. Individually housed mice were exposed to anosmic “standard opponents” 30 min after drug administration. Ten min of diadic interactions were staged between a singly housed and an anosmic mouse in a neutral area. The encounters were videotaped and the accumulated time allocated by subjects to ten broad behavioural categories was estimated using an ethologically based analysis. LY379268 (2 mg/kg) significantly reduced attack behaviour, as compared with the control group, without affecting immobility, whereas the highest dose of the drug (4 mg/kg) also decreased offensive behaviours (threat and attack), but with a marked increase of immobility (non-selective effect). These results indicate that mGlu2/3 receptors might be implicated in the modulation of aggression.

Anxiogenic-like effects of gamma-hydroxybutyric acid (GHB) in mice tested in the light-dark box

Gamma-hydroxybutyric acid (GHB) is a drug with abuse potential, popularly known as "liquid ecstasy". It is an endogenous compound of the mammalian brain which satisfies many of the criteria for consideration as a neurotransmitter or neuromodulator. In this study, the effects of acute administration of GHB (40, 80 and 120 mg/kg, ip) on anxiety, tested in the light/dark box, were examined in male mice of the OF.1 strain. Likewise, we compared the behavioural profile of GHB with that induced by mCPP (1 mg/kg, ip), a compound with known anxiogenic actions. GHB-treated mice spent notably less time in the lit area (40 and 80 mg/kg) and more time in the dark area (all doses), whereas the total number of 'rearings', transitions and latency were significantly reduced. A very similar behavioural profile was observed in mCPP-treated animals. Overall, these findings indicate that GHB exhibits anxiogenic-like properties in male mice. It is suggested that the anxiogenic effects of GHB could be related to its ability to modulate GABA and/or dopaminergic receptors.

Effects of SB-205384, a positive modulator of alpha3-subunit-containing GABA-A receptors, on isolation-induced aggression in male mice

GABA-A receptors are involved in the control of aggressive behaviour. Various studies suggest a role for a1-containing GABA-A receptors in modulating aggression. However, the possible involvement of a3 subunit of GABA-A receptors has not been examined. In this study, we analysed the effect of SB-205384 (0.5-4 mg/kg, i.p), a positive modulator of GABA-A receptors containing a3 subunit, on agonistic behaviour elicited by isolation in male mice. Half of the mice were housed during 30 days and employed as experimental or control animals; the remainder were used as <<opponents>> and were temporally rendered anosmic by zinc sulphate. Individually housed mice were exposed to anosmic opponents in a neutral area 30 minutes after the drug administration and encounters were videotaped and evaluated using an ethopharmacologically-based analysis. The results indicated that SB-205384 did not produce any significant behavioural changes, suggesting that GABA-A receptors which contain the a3 subunit may not be involved in the modulation of aggression.

[Novelties in the field of progression factors in chronic kidney disease]

The fight against chronic kidney disease is one of the most relevant aspects of nephrological practice, from both the perspective of clinical activity and research within the field of nephrology. In this brief article, we present in very summarized form some of the aspects in this field in the last year that the authors found of interest. Because the content of the next few pages was necessarily chosen on the basis of the authors' preferences, we assume that many other topics of great interest have been left out of this summary. In any case, we hope that this article will be interesting and useful and also serve as an subject of debate in nephrology forums.

Incidence of Beijing genotype of Mycobacterium tuberculosis in Elche, Spain: A 13-year surveillance study

Binary file ES_Abstracts_Final_ECDC.txt matches

Anti-aggressive effects of GHB in OF.1 strain mice: involvement of dopamine D2 receptors

Numerous studies indicate that gamma-hydroxybutyric acid (GHB) influences the endogenous dopamine system. Both GHB and most dopaminergic D(2) receptor antagonists are effective anti-aggressive agents in animal models. The present study aimed to investigate the effects of GHB on agonistic behaviour and to implicate D(2) dopamine receptor on these behaviours. For this purpose, the effects of GHB (80, 120 and 160 mg/kg, IP) and tiapride (60 mg/kg) administered alone or in combination were examined on agonistic behaviour elicited by 'isolation' in male mice. Individually housed mice were exposed to anosmic "standard opponents" 30 min after drug administration, and the encounters were videotaped and evaluated using an ethologically based analysis. The administration of 80 and 120 mg/kg of GHB reduced threat without impairing motor activity, but the administration of 160 mg/kg of GHB or the co-administration of GHB+tiapride (a selective D(2) receptor antagonist) significantly reduced threat and attack but concomitantly increased immobility. The co-administration of GHB+tiapride had different effects to those observed by the administration of these drugs separately. It is concluded that the anti-aggressive effect of GHB appears to be mediated, at least in part, by D(2) dopamine receptors. This anti-dopaminergic activity is an indirect effect, probably induced by the activation of GHB receptors of low affinity, and in this way, this compound would reduce levels of dopamine without blockading of D(2) postsynaptic dopamine receptors.

Monte Carlo based voxel phantoms for in vivo internal dosimetry

The purpose of this communication is to describe briefly the computer programs developed to generate the MCNP input file corresponding to any segmented tomographic data and its application to the calibration procedures for in vivo internal dosimetry. The method has been applied to the determination of 241Am in bone by measurement in skull and knee using MCNP voxel models of a real human head and knee based on the tomographic Voxelman and Arms Down phantoms developed by Zubal et al. at Yale University.

Assessment of the internal dose of 241Am in bone by in vivo measurements of activity deposited in knee

In case of chronic exposure or long time after an acute intake of (241)Am as a consequence of an incident, the assessment of internal dose might be realised by estimating the total activity content of this element in the skeleton. For this purpose, a new methodology has been developed at the Whole Body Counting Laboratory of CIEMAT. In vivo measurements of this bone-seeker radionuclide in the knee are performed using four low energy germanium detectors inside a shielded room. The sensitivity study of this technique resulted in a minimum detectable activity of 7 Bq, for a counting time of 1800 s. Extrapolation to the total activity in the bone has been carried out by taking into account that the bone content of the knee calibration phantom is equivalent to 10.7% of the whole skeleton mass. The results of in vivo measurements of population and the procedure for internal dose evaluation are presented here.

Antiaggressive effects of MPEP, a selective antagonist of mGlu5 receptors, in agonistic interactions between male mice

mGlu5 receptors are highly concentrated in limbic brain structures involved in motivational and emotional behaviours. This study describes the effects of 2-methyl-6-(phenylethylnyl)pyridine (MPEP; 5, 10, 15, 20 and 25 mg/kg, ip), a selective antagonist of the mGlu5 receptors, on agonistic behaviour elicited by isolation in male mice. Individually housed mice were exposed to anosmic opponents in a neutral area 30 min after drug administration. Besides other behaviours, the aggressive (threat and attack) and exploratory behaviours were evaluated during 10 min using an ethologically based analysis. MPEP produced a behavioural profile characterized by a notable decrement of offensive behaviours, accompanied by a significant increase of exploratory behaviours (nonsocial exploration and social investigation). These findings suggest a role for mGlu5 receptors in aggression modulation.

[Update on gamma-hydroxybutyric acid]

AIMS

The article offers an updated review of the main pharmacological aspects of gamma-hydroxybutyric acid (GHB), as well as its clinical and behavioural effects.

DEVELOPMENT

A number of pharmacological, neurochemical and electrophysiological studies have clearly shown that endogenous GHB plays a role as a neurotransmitter and/or neuromodulator in the central nervous system (CNS). GHB displays specific synthesis, release and reuptake mechanisms, as well as particular binding sites that suggest the existence of a central GHBergic system. This substance, popularly known as 'liquid ecstasy', is also a potentially abusable drug; if administered for prolonged periods of time it can lead to dependence and withdrawal symptoms after the patient stops taking it. Its chief behavioural actions include sedation/sleepiness, induction of absence seizures, catalepsy or reduced aggression, among others. Some of these effects appear to be related to an interaction that has been reported to exist between the GHBergic system and the dopaminergic and GABAergic receptors in the CNS. From the clinical point of view, its use has been approved in some countries to treat the narcoleptic syndrome, and it has also been considered for possible use in the treatment of alcohol or opiate abuse. Finally, recent studies conducted with laboratory animals suggest the existence of a possible neurotoxic effect following prolonged administration in abusable dosages.

CONCLUSIONS

GHB is an extraordinarily interesting compound. It acts as a neurotransmitter/neuromodulator in the CNS. It is also an abusable recreational drug and may also be used to treat a number of different pathological conditions, the most important of which is narcolepsy. The possible development of neurotoxicity following prolonged administration, however, imposes considerable limitations on its usefulness in clinical contexts.

Effects of selective dopamine D4 receptor antagonist, L-741,741, on sleep and wakefulness in the rat

The influence of the dopamine system upon sleep/wake states is not fully understood. To date, the role of dopamine D4 receptor has not been studied. The aim of this work is to study the influence of dopamine D4 receptor upon sleep/wake states in male rats. Male Wistar rats were implanted with electroencephalography and electromyography electrodes for sleep recording. Sleep/wake times were compared in rats first treated with control solution (vehicle) and the day after treated with a potent and highly selective D4 dopamine receptor antagonist. L-741,741 (1.5, 3, 6 mg/kg) or vehicle solution (10% DMSO in saline) was administered intraperitoneally at the beginning of the light period. Subsequently, 3 h of polysomnography were recorded and sleep-wake parameters evaluated. For statistical comparisons, Wilcoxon ranges test was performed. L-741,741 (1.5 mg/kg) only increased Light Slow Wave Sleep (SWS). 3 mg/kg enhanced Quiet Waking (QW) increasing number of episodes, whereas Active Waking (AW) was reduced decreasing mean episode duration. 6 mg/kg reduced number of episodes of Deep SWS and increased its latency. Light SWS was decreased reducing number of episodes and their duration. Total time spent asleep was reduced and time spent in AW was increased. REM latency was increased. These results suggest a role for D4 receptors in the regulation of wake and sleep.

Anxiolytic-like activity of SB-205384 in the elevated plus-maze test in mice

Recent studies point to a major role for alpha2-containing GABA-A receptors in modulating anxiety. However, the possible implication of GABA-A receptors containing the alpha3 subunit on anxiety is less known. The aim of this study was to examine the effects of SB-205384 (0.5-4 mg/kg, i.p.), an alpha3 subunit positive modulator of GABA-A receptor, on anxiety tested in the elevated plus-maze in male mice, using classical and ethological parameters. Mice treated with SB-205384 showed an increase in the frequency of entries and the time spent in open arms, as well as a reduction in the time spent in closed arms, as compared with the control group. A notable increase of "head-dipping" unprotected and a reduction of "stretched-attend posture" protected was also evident. These findings indicate that SB-205384 exhibits an anxiolytic-like profile in the elevated plus-maze test, suggesting that GABA-A receptors which contain the alpha3 subunit might be involved in regulation of anxiety.

Effects of (+)SKF 10047, a sigma-1 selective agonist, on isolation-induced aggression in male mice

sigma-1 Receptors have been identified in numerous brain regions, including areas such as hypothalamus and amygdala, which have long been linked to the regulation of aggression. However, there is no clear information with respect to the possible effects of sigma-1 ligands on aggressive behavior in laboratory animals. Consequently, the present study examined the effects of (+)SKF 10047 (0.5-6 mg/kg, i.p.), a sigma-1 prototypical agonist, on isolation-induced aggression in male mice, using an ethopharmacological approach. Individually housed mice were exposed to anosmic "standard opponents" 30 min after drug administration. Ten minutes of diadic interactions were staged between a singly housed and an anosmic mouse in a neutral area. The encounters were videotaped, and the accumulated time allocated by subjects to 10 broad behavioral categories was estimated using an ethologically based analysis. Results showed that (+)SKF 10047 (6 mg/kg) produced a significant reduction of offensive behaviors, without affecting immobility. Social investigation behaviors were also slightly increased after drug treatment (2-6 mg/kg). These results suggest a role for sigma-1 receptors in aggression modulation in mice.

Effects of selective neuronal nitric oxide synthase inhibition on sleep and wakefulness in the rat

The role played by the unconventional messenger Nitric Oxide (NO) upon the sleep-wake cycle remains controversial. Evidence suggests a positive role of NO on Slow Wave Sleep (SWS) and Paradoxical Sleep (PS) regulation, favoring sleep. However, other studies have found a role of NO upon wakefulness and alertness, inhibiting sleep. Divergences have been explained in part because of the use of different inhibitors of nitric oxide synthases (NOS). The aim of this study is to analyse the effects of a highly selective neuronal NOS inhibitor (3-Bromo7-Nitroindazole) on sleep-wake states in rats. Male Wistar rats were stereotaxically prepared for polysomnography. 3-Bromo-7-Nitroindazole (10, 20, 40 mg/kg, i.p.) dissolved in DMSO 10% filled with saline, or vehicle (DMSO 10% in saline) was administered at the beginning of the light period. Three hours of polygraphic recordings were evaluated for stages of vigilance. Results show dose-dependent effects of 3-Bromo7-Nitroindazole upon sleep: 10 mg/kg decreases duration and number of episodes of deep SWS, increasing duration of light SWS. 20 mg/kg decreased duration of light and deep SWS, while active and quiet wake increased. Deep SWS and PS latency increased. Number of episodes of PS decreased, as well as number of cycles of sleep and time spent asleep. 40 mg/kg reduced duration of deep SWS and increased mean episode duration of light SWS. Therefore, sleep states are affected by selective inhibition of nNOS, reducing in all cases deep SWS. These results support the hypothesis that nitric oxide, produced by nNOS, is involved in sleep processes, favoring sleep.

Behavioral profile of SB 269970, a selective 5-HT(7) serotonin receptor antagonist, in social encounters between male mice

The 5-HT(7) receptor is targeted by several antipsychotics, such as pimozide or clozapine, which have demonstrated antiaggressive properties in laboratory animal models. Likewise, 'in situ' hybridization and autoradiography studies have revealed moderate to high densities of 5-HT(7) receptors in limbic areas and hypothalamus, which have long been involved in the control of aggression. However, to date there is no evidence concerning the role of this receptor in the regulation of aggression. This study was designed to examine the effects of SB 269970 (1, 2, 4, 8, 16 and 32 mg/kg, i.p.), a selective 5-HT(7) receptor antagonist, on agonistic behavior elicited by isolation in mice. Individually housed mice were exposed to anosmic standard opponents 15 min after drug administration and encounters were videotaped and evaluated using an ethopharmacologically-based analysis. The results indicated that SB 269970 did not produce any significant behavioral changes, suggesting that 5-HT(7) receptors might not be involved in the modulation of aggression. Further studies with other selective ligands for these receptors are needed to confirm these findings.