Interpretative phenomenological analysis of the collaboration among healthcare professionals in the nursing home setting.

Background: The theory of planned behavior (TPB) postulates that behavioral performance is guided by the intention to perform that behavior, influenced by attitudes, subjective norms, and perceived behavioral control. This framework can be applied to studying interprofessional collaboration among healthcare professionals to enhance patient safety and public health within nursing homes. Objectives: This study aimed to explore the roles of physicians, pharmacists, and nurses in the interprofessional collaboration process while identifying facilitators and barriers to effective collaboration among healthcare professionals. Methods: A qualitative interpretative phenomenological analysis (IPA) was carried out. Individual semi-structured interviews were conducted with 19 healthcare professionals. Qualitative data were then integrated and analyzed through the lens of the TPB. Findings: The IPA revealed the ten following themes, considered as both facilitators and barriers to interprofessional collaboration among healthcare professionals in the nursing home setting: communication, roles and responsibilities, willingness and recognition of collaboration's importance, mutual knowledge, trust, confidence, support from decision-makers, protocols, and technology were considered as facilitators while distance was considered as a barrier. Conclusion: Enhancing pharmacist-physician collaboration and refining pharmacist-nurse collaboration were essential goals. Intention for collaboration was influenced by attitudes (such as communication and mutual understanding), subjective norms (including support from decision-makers), and perceived behavioral control (such as confidence and adherence to protocols and technology). Addressing these factors could improve collaboration, enhancing residents' quality of life and professionals' sense of achievement.

Vaccine hesitancy for the COVID-19 vaccine booster dose among nursing home staff fully vaccinated with the primary vaccination course in Belgium.

In Belgium, nursing home (NH) staff (NHS) and residents were prioritised for the initial COVID-19 vaccination and successive booster doses. The vaccination campaign for the first booster started in September 2021 in Belgian NH. Our first study about vaccine hesitancy towards the COVID-19 vaccine in Belgian NHS already showed a degree of fear for the primary vaccination course (T1). This new study aims to evaluate vaccine hesitancy to get the first booster (T2) in a population of fully vaccinated (with two doses) NHS. A random stratified sample of NHS who received the primary vaccination course (N = 954) completed an online questionnaire on COVID-19 booster hesitancy (between 25/11/2021 and 22/01/2022). NHS who hesitated or refused the booster were asked for the main reason for their hesitation/refusal. Overall, 21.0 % of our population hesitated before, were still hesitating or refused the booster, NHS that were not hesitant at T1 being 5.7 times less likely to hesitate to get the first booster dose (Adjusted OR 0.179, 95 % CI: 0.120, 0.267). Although there was a slight reduction (23.5 % to 20.1 %) in the proportion of NHS who hesitated/refused vaccination at T1 compared to T2 (p = 0.034), the fear of unknown effects was the principal reason for hesitation/refusal, already mentioned in our first study. NHS were not reassured concerning their initial fears. Given the likelihood that booster vaccinations will be necessary over the coming years, a communication strategy specific to NHS should be implemented.

The DAWN antivirals trial: process evaluation of a COVID-19 trial in general practice.

BACKGROUND: The DAWN antivirals trial was a multicentric, randomised placebo-controlled trial evaluating antiviral medication for COVID-19 in general practice. The trial was prematurely terminated because of insufficient recruitment. AIM: To explore which factors contributed to the premature termination. DESIGN & SETTING: General practice in Belgium. METHOD: Patients were randomised to camostat or placebo (patients and physicians blinded) between June 2021 and July 2022; a third arm evaluating molnupiravir (open label) was opened in March 2022. The outcome assessor was blinded for all comparisons except for the patient reported outcomes in case of molnupiravir. The authors analysed available trial data and evaluated trial context, implementation, and mechanisms of impact based on semi-structured interviews with trial stakeholders. RESULTS: The trial recruited 44 participants; 19 were allocated to camostat (median age 55 years), 8 to molnupiravir (median age 60 years), and 17 to placebo (median age 56 years). There were no serious adverse events in either group. Most difficulties were related to the pandemic context: disruption to routine clinical services; multiple changes to the service model for COVID-19 patients; overwhelmed clinical staff; delays of trial medication; and staff shortages in the sponsor and clinical team. In addition, regulatory approval processes were lengthy and led to additional study procedures. It was felt that the trial started too late, when vaccinations had already begun. CONCLUSION: The DAWN antivirals trial was stopped prematurely. Although many barriers were related to the pandemic itself, hurdles such as a small and inexperienced sponsor and clinical teams, delays in regulatory processes, and research capacity in routine settings could be overcome by established research infrastructure and standardisation of processes.

Validation of a rapid SARS-CoV-2 antibody test in general practice.

OBJECTIVES: To validate a rapid serological test (RST) for SARS-CoV-2 antibodies used in seroprevalence studies in healthcare providers, including primary healthcare providers (PHCPs) in Belgium. DESIGN: A phase III validation study of the RST (OrientGene) within a prospective cohort study. SETTING: Primary care in Belgium. PARTICIPANTS: Any general practitioner (GP) working in primary care in Belgium and any other PHCP from the same GP practice who physically manages patients were eligible in the seroprevalence study. For the validation study, all participants who tested positive (376) on the RST at the first testing timepoint (T1) and a random sample of those who tested negative (790) and unclear (24) were included. INTERVENTION: At T2, 4 weeks later, PHCPs performed the RST with fingerprick blood (index test) immediately after providing a serum sample to be analysed for the presence of SARS-CoV-2 immunoglobulin G antibodies using a two-out-of-three assay (reference test). PRIMARY AND SECONDARY OUTCOME MEASURES: The RST accuracy was estimated using inverse probability weighting to correct for missing reference test data, and considering unclear RST results as negative for the sensitivity and positive for the specificity. Using these conservative estimates, the true seroprevalence was estimated both for T2 and RST-based prevalence values found in a cohort study with PHCPs in Belgium. RESULTS: 1073 paired tests (403 positive on the reference test) were included. A sensitivity of 73% (a specificity of 92%) was found considering unclear RST results as negative (positive). For an RST-based prevalence at T1 (13.9), T2 (24.9) and T7 (70.21), the true prevalence was estimated to be 9.1%, 25.9% and 95.7%, respectively. CONCLUSION: The RST sensitivity (73%) and specificity (92%) make an RST-based seroprevalence below (above) 23% overestimate (underestimate) the true seroprevalence. TRIAL REGISTRATION NUMBER: NCT04779424.

Prevalence of SARS-CoV-2 antibodies among Belgian nursing home residents and staff during the primary COVID-19 vaccination campaign.

BACKGROUND: Nursing home residents (NHR) and staff have been disproportionally affected by the COVID-19 pandemic and were therefore prioritised in the COVID-19 vaccination strategy. However, frail older adults, like NHR, are known to have decreased antibody responses upon vaccination targeting other viral antigens. OBJECTIVES: As real-world data on vaccine responsiveness, we assessed the prevalence of SARS-CoV-2 antibodies among Belgian NHR and staff during the primary COVID-19 vaccination campaign. METHODS: In total, we tested 1629 NHR and 1356 staff across 69 Belgian NHs for the presence of SARS-CoV-2 IgM/IgG antibodies using rapid tests. We collected socio-demographic and COVID-19-related medical data through questionnaires. Sampling occurred between 1 February and 24 March 2021, in a randomly sampled population that received none, one or two BNT162b2 vaccine doses. RESULTS: We found that during the primary vaccination campaign with 59% of the study population fully vaccinated, 74% had SARS-CoV-2 antibodies. Among fully vaccinated individuals only, fewer residents tested positive for SARS-CoV-2 antibodies (77%) than staff (98%), suggesting an impaired vaccine-induced antibody response in the elderly, with lowest seroprevalences observed among infection naïve residents. COVID-19 vaccination status and previous SARS-CoV-2 infection were predictors for SARS-CoV-2 seropositivity. Alternatively, age ≥ 80 years old, the presence of comorbidities and high care dependency predicted SARS-CoV-2 seronegativity in NHR. CONCLUSION: These findings highlight the need for further monitoring of SARS-CoV-2 immunity upon vaccination in the elderly population, as their impaired humoral responses could imply insufficient protection against COVID-19. TRIAL REGISTRATION: This study was retrospectively registered on ClinicalTrials.gov (NCT04738695).

Declining Prevalence of SARS-CoV-2 Antibodies among Vaccinated Nursing Home Residents and Staff Six Months after the Primary BNT162b2 Vaccination Campaign in Belgium: A Prospective Cohort Study.

In the SCOPE study, we monitored SARS-CoV-2 antibodies in a national sample of residents and staff from Belgian nursing homes. Here, we report the seroprevalence among infected and infection-naive residents and staff after the primary COVID-19 vaccination campaign. Among 1554 vaccinated nursing home residents and 1082 vaccinated staff from 69 nursing homes in Belgium, we assessed the proportion having SARS-CoV-2 antibodies approximately two (April 2021), four (June 2021), and six months (August 2021) after a two-dose regimen of the BNT162b2 vaccine. We measured the seroprevalence using SARS-CoV-2 antibody rapid tests and collected socio-demographic and COVID-19 medical data using an online questionnaire. Two months after vaccination (baseline), we found a seroprevalence of 91% (95% CI: 89-93) among vaccinated residents and 99% (95% CI: 98-99) among vaccinated staff. Six months after vaccination, the seroprevalence significantly decreased to 68% (95% CI: 64-72) among residents and to 89% (95% CI; 86-91) among staff (p < 0.001). The seroprevalence was more likely to decrease among infection-naive residents, older residents, or residents with a high care dependency level. These findings emphasize the need for close monitoring of nursing home residents, as a substantial part of this population fails to mount a persistent antibody response after BNT162b2 vaccination.

Prevalence, incidence and longevity of antibodies against SARS-CoV-2 among primary healthcare providers in Belgium: a prospective cohort study with 12 months of follow-up.

OBJECTIVES: To estimate the prevalence, incidence and longevity of antibodies against SARS-CoV-2 among primary healthcare providers (PHCPs). DESIGN: Prospective cohort study with 12 months of follow-up. SETTING: Primary care in Belgium. PARTICIPANTS: Any general practitioner (GP) working in primary care in Belgium and any other PHCP from the same GP practice who physically manages (examines, tests, treats) patients were eligible. A convenience sample of 3648 eligible PHCPs from 2001 GP practices registered for this study (3044 and 604 to start in December 2020 and January 2021, respectively). 3390 PHCPs (92,9%) participated in their first testing time point (2820 and 565, respectively) and 2557 PHCPs (70,1%) in the last testing time point (December 2021). INTERVENTIONS: Participants were asked to perform a rapid serological test targeting IgM and IgG against the receptor binding domain of SARS-CoV-2 and to complete an online questionnaire at each of maximum eight testing time points. PRIMARY AND SECONDARY OUTCOME MEASURES: The prevalence, incidence and longevity of antibodies against SARS-CoV-2 both after natural infection and after vaccination. RESULTS: Among all participants, 67% were women and 77% GPs. Median age was 43 years. The seroprevalence in December 2020 (before vaccination availability) was 15.1% (95% CI 13.5% to 16.6%), increased to 84.2% (95% CI 82.9% to 85.5%) in March 2021 (after vaccination availability) and reached 93.9% (95% CI 92.9% to 94.9%) in December 2021 (during booster vaccination availability and fourth (delta variant dominant) COVID-19 wave). Among not (yet) vaccinated participants the first monthly incidence of antibodies against SARS-CoV-2 was estimated to be 2.91% (95% CI 1.80% to 4.01%). The longevity of antibodies is higher in PHCPs with self-reported COVID-19 infection. CONCLUSIONS: This study confirms that occupational health measures provided sufficient protection when managing patients. High uptake of vaccination resulted in high seroprevalence of SARS-CoV-2 antibodies in PHCPs in Belgium. Longevity of antibodies was supported by booster vaccination and virus circulation. TRIAL REGISTRATION NUMBER: NCT04779424.

Mapping the current knowledge in syndemic research applied to men who have sex with men: A scoping review.

Men who have sex with Men (MSM) represent a population affected by numerous health conditions. Syndemic theory has been used as a framework to study the health of MSM for nearly 20 years. However, the literature is plagued by a lack of consensus regarding what constitutes a synergy in a syndemic and recent reviews have shown that most of the papers published thus far have failed to demonstrate a synergy nor describe the bio-social interaction needed to account for a true syndemic. Moreover, to our knowledge, none of the existing reviews have focused specifically on MSM. This scoping review aims to fill this gap by mapping in detail how syndemic research on MSM has been conducted. A systematic database search was conducted between 2020 and 2021 and 115 studies were included. Our findings showed a lack of diversity regarding the location, design, subpopulation, and outcomes studied. In addition, the syndemic conditions, as well as their measurement, were not focused enough to ensure the robustness and reproducibility of the findings. Furthermore, our results support previous reviews showing a lack of empirical data to support disease interaction in syndemic research applied to MSM. Our review offers some important recommendations to help move the field forward in future work and describes some promising methodological advances.

Vaccine Hesitancy towards the COVID-19 Vaccine in a Random National Sample of Belgian Nursing Home Staff Members.

In Belgium, nursing home staff (NHS) and residents were prioritised for COVID-19 vaccination. However, vaccine hesitancy may have impacted vaccination rates. In this study, a random stratified sample of NHS (N = 1142), vaccinated and unvaccinated, completed an online questionnaire on COVID-19 vaccine hesitancy (between 31 July and 15 November 2021). NHS who hesitated or refused the vaccine were asked for the main reason for their hesitation/refusal. Those who hesitated, but eventually accepted vaccination, were asked why they changed their minds. Overall, 29.5% of all respondents hesitated before accepting vaccination, were still hesitating, or refused vaccination. Principal reasons were fear of unknown future effects (55.1% of vaccinated participants that hesitated and 19.5% who refused), fear of side-effects (12.7% of vaccinated participants that hesitated and 12.2% who refused), and mistrust in vaccination (10.5% of vaccinated participants that hesitated and 12.2% who refused). For vaccinated participants who hesitated initially, protecting the vulnerable was the main reason they changed their minds. Given this degree of fear and proposals to mandate vaccination among healthcare workers, communicating with NHS on the safety and efficacy of the vaccine should be prioritised.

Prevalence and incidence of antibodies against SARS-CoV-2 among primary healthcare providers in Belgium during 1 year of the COVID-19 epidemic: prospective cohort study protocol.

INTRODUCTION: National SARS-CoV-2 seroprevalence data provide essential information about population exposure to the virus and help predict the future course of the epidemic. Early cohort studies have suggested declines in levels of antibodies in individuals associated with, for example, illness severity, age and comorbidities. This protocol focuses on the seroprevalence among primary healthcare providers (PHCPs) in Belgium. PHCPs manage the vast majority of (COVID-19) patients and therefore play an essential role in the efficient organisation of healthcare. Currently, evidence is lacking on (1) how many PHCPs get infected with SARS-CoV-2 in Belgium, (2) the rate at which this happens, (3) their clinical spectrum, (4) their risk factors, (5) the effectiveness of the measures to prevent infection and (6) the accuracy of the serology-based point-of-care test (POCT) in a primary care setting. METHODS AND ANALYSIS: This study will be set up as a prospective cohort study. General practitioners (GPs) and other PHCPs (working in a GP practice) will be recruited via professional networks and professional media outlets to register online to participate. Registered GPs and other PHCPs will be asked at each testing point (n=9) to perform a capillary blood sample antibody POCT targeting IgM and IgG against the receptor-binding domain of SARS-CoV-2 and complete an online questionnaire. The primary outcomes are the prevalence and incidence of antibodies against SARS-CoV-2 in PHCPs during a 12-month follow-up period. Secondary outcomes include the longevity of antibodies against SARS-CoV-2. ETHICS AND DISSEMINATION: Ethical approval has been granted by the ethics committee of the University Hospital of Antwerp/University of Antwerp (Belgian registration number: 3002020000237). Alongside journal publications, dissemination activities include the publication of monthly reports to be shared with the participants and the general population through the publicly available website of the Belgian health authorities (Sciensano). TRIAL REGISTRATION NUMBER: NCT04779424.

Mapping the current knowledge in syndemic research applied to men who have sex with men: a scoping review protocol.

INTRODUCTION: Men who have sex with men (MSM) are disproportionally affected by a number of health conditions that are associated with violence, stigma, discrimination, poverty, unemployment or poor healthcare access. In recent years, syndemic theory provided a framework to explore the interactions of these health disparities on the biological and social levels. Research in this field has been increasing for the past 10 years, but methodologies have evolved and sometimes differed from the original concept. The aim of this paper is to provide an overview of the existing literature on syndemic theory applied to MSM in order to identify knowledge gaps, inform future investigations and expand our understanding of the complex interactions between avoidable health conditions in a vulnerable population. METHODS AND ANALYSIS: The proposed scoping review will follow the methodological framework developed by Arksey and O'Malley with subsequent enhancements by Levac et al, Colquhoun et al and Peters et al as well as the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping review. A systematic search of MEDLINE, PsycInfo, Scopus, Cochrane Central Register of Controlled Trials and ProQuest Sociological Abstracts will be conducted. Reference lists of the included studies will be hand-searched for additional studies. Screening and data charting will be achieved using DistillerSR. Data collating, summarising and reporting will be performed using R and RStudio. Tabular and graphical summaries will be presented, alongside an evidence map and a descriptive overview of the main results. ETHICS AND DISSEMINATION: This scoping review does not require ethical approval. Data and code will be made accessible after manuscript submission. Final results will be disseminated through publication in a peer-reviewed journal and collaboration with grassroots Lesbian, Gay, Bisexual, Transgender, Queer, Intersex and Asexual (LGBTQIA+) organisations. REGISTRATION: This protocol was registered on manuscript submission on the Open Science Framework at the following address: https://osf.io/jwxtd; DOI: 10.17605/OSF.IO/JWXTD.

Involvement of brain-derived neurotrophic factor (BDNF) in the long-term memory effects of glucocorticoid stimulation during adolescence/young adulthood.

Brain-derived neurotrophic factor (BDNF) has been implicated in cognition and the effects of chronic stress. We have previously shown in mice that chronic adolescent treatment with corticosterone (CORT), to simulate stress, resulted in spatial memory deficits and markedly elevated levels of the N-methyl-D-aspartate (NMDA) receptor subunit NR2B in adult male BDNF heterozygous mice (BDNF+/-), but not in wildtype controls (WT) or females. The aim of the present study was to further characterize this 'two hit' model, including whether these effects are long-lasting. CORT treatment was delivered in the drinking water from 6 to 9 weeks of age. As previously demonstrated, male BDNF+/- mice treated with CORT presented with a deficit in spatial memory at 11 weeks of age. However, this deficit was not maintained at 15 weeks of age. Conversely, male WT treated with CORT developed a deficit only at 15 weeks of age. There were no significant gene-environment interactions in female mice at any time point. CORT treatment caused a modest, but significant increase in NR2B levels which was independent of genotype. These results show marked age-dependent and sex-dependent effects of CORT on behaviour which are different in BDNF+/- mice than in controls.

Dealing with health literacy at the organisational level, French translation and adaptation of the Vienna health literate organisation self-assessment tool.

BACKGROUND: Efforts to address health literacy should favour a system-based approach with the dual aim both of fostering the material conditions and creating a work culture inside health care organisations that makes it easier for people to use information. The Vienna Health Literate Organisation (V-HLO) self-assessment tool is a German-speaking questionnaire for quality managers of health care organisations. Its objective is to provide a diagnostic of the strengths and weaknesses of the organisation in terms of health literacy. Our goal was to translate and culturally adapt this questionnaire for the French-speaking part of Belgium. METHODS: We followed the Translation, Review, Adjudication, Pretesting, and Documentation (TRAPD) team model for cross-cultural translation of questionnaires. We used cognitive interviews with quality experts to pre-test the translation. RESULTS: Cognitive interviews allowed us to improve the translation by removing certain ambiguities, providing contextual clarifications or rephrasing some items in such a way as to render them more culturally appropriate. Local experts generally judged the tool to be relevant and applicable to their context. The insight gained with regard to their cognitive process when completing the V-HLO allowed us to identify possible barriers to the adoption of the tool (such as difficulties in considering staff literacy as a relevant target for the tool, fear of overwhelming staff, a feeling that some items fell outside the scope of health literacy and lack of attention for integration of services with primary care) and could contribute to the future development of the tool. CONCLUSION: We translated and adapted the V-HLO self-assessment tool for French. The French version of the V-HLO will now be implemented in our local context to assess whether it can make it easier for people to deal with the complexities of health care organisations.

[Health literacy, a lever to make health care systems more equitable? Tools to support professionals and involve institutions]. / La littératie en santé, un levier pour des systèmes de soins plus équitables Des outils pour armer les professionnels et impliquer les institutions.

This article briefly recalls why low levels of health literacy should be considered to constitute a public health issue. It then proposes the concept of health literacy as a possible lever to help health care systems to more effectively take social health inequalities into account. Finally, it provides concrete tools for field workers, both clinicians and quality of care managers, and emphasises the importance of an organizational approach to health literacy.

Chloroplastic and nuclear diversity of wild beets at a large geographical scale: Insights into the evolutionary history of the Beta section.

Historical demographic processes and mating systems are believed to be major factors in the shaping of the intraspecies genetic diversity of plants. Among Caryophyllales, the Beta section of the genus Beta, within the Amaranthaceae/Chenopodiaceae alliance, is an interesting study model with species and subspecies (Beta macrocarpa, Beta patula, Beta vulgaris maritima and B.v. adanensis) differing in geographical distribution and mating system. In addition, one of the species, B. macrocarpa, mainly diploid, varies in its level of ploidy with a tetraploid cytotype described in the Canary Islands and in Portugal. In this study, we analyzed the nucleotide diversity of chloroplastic and nuclear sequences on a representative sampling of species and subspecies of the Beta section (except B. patula). Our objectives were (1) to assess their genetic relationships through phylogenetic and multivariate analyses, (2) relate their genetic diversity to their mating system, and (3) reconsider the ploidy status and the origin of the Canarian Beta macrocarpa.

Gene-environment interaction of reelin and stress in cognitive behaviours in mice: Implications for schizophrenia.

Cognitive deficits are a particularly debilitating symptom group in schizophrenia. We investigated the effect of a 'two hit' combination of two factors implicated in schizophrenia development, reelin deficiency and stress, on cognitive behaviours in mice. Male and female heterozygous reelin mice (HRM) and wild-type (WT) controls received the stress hormone, corticosterone (CORT), during early adulthood to simulate chronic stress. The Y-maze, novel object recognition task (NORT), social interaction task and prepulse inhibition (PPI) were used to assess short-term spatial memory, visual non-spatial memory, social recognition memory and sensory gating, respectively. Reelin protein expression was measured in the prefrontal cortex (PFC) and hippocampus. CORT induced spatial memory deficits in male and female HRM but not in WT controls suggesting increased vulnerability of HRM to the effects of stress on cognition. By contrast, CORT disrupted PPI only in male WT mice, but not in male HRM, suggesting a protective role of reelin deficiency against effects of stress on PPI. Male HRM performed worse in the social recognition memory task compared to wild-type controls, irrespective of CORT treatment. No differences were detected in the NORT. Reelin protein expression was increased in the PFC of female CORT-treated HRM but there were no group differences in the hippocampus. Overall, these findings extend our understanding of the role of reelin-stress interactions in schizophrenia.

Environmental Enrichment Ameliorates Behavioral Impairments Modeling Schizophrenia in Mice Lacking Metabotropic Glutamate Receptor 5.

Schizophrenia arises from a complex interplay between genetic and environmental factors. Abnormalities in glutamatergic signaling have been proposed to underlie the emergence of symptoms, in light of various lines of evidence, including the psychotomimetic effects of NMDA receptor antagonists. Metabotropic glutamate receptor 5 (mGlu5) has also been implicated in the disorder, and has been shown to physically interact with NMDA receptors. To clarify the role of mGlu5-dependent behavioral expression by environmental factors, we assessed mGlu5 knockout (KO) mice after exposure to environmental enrichment (EE) or reared under standard conditions. The mGlu5 KO mice showed reduced prepulse inhibition (PPI), long-term memory deficits, and spontaneous locomotor hyperactivity, which were all attenuated by EE. Examining the cellular impact of genetic and environmental manipulation, we show that EE significantly increased pyramidal cell dendritic branching and BDNF protein levels in the hippocampus of wild-type mice; however, mGlu5 KO mice were resistant to these alterations, suggesting that mGlu5 is critical to these responses. A selective effect of EE on the behavioral response to the NMDA receptor antagonist MK-801 in mGlu5 KO mice was seen. MK-801-induced hyperlocomotion was further potentiated in enriched mGlu5 KO mice and treatment with MK-801 reinstated PPI disruption in EE mGlu5 KO mice only, a response that is absent under standard housing conditions. Together, these results demonstrate an important role for mGlu5 in environmental modulation of schizophrenia-related behavioral impairments. Furthermore, this role of the mGlu5 receptor is mediated by interaction with NMDA receptor function, which may inform development of novel therapeutics.

Corticosterone treatment during adolescence induces down-regulation of reelin and NMDA receptor subunit GLUN2C expression only in male mice: implications for schizophrenia.

Stress exposure during adolescence/early adulthood has been shown to increase the risk for psychiatric disorders such as schizophrenia. Reelin plays an essential role in brain development and its levels are decreased in schizophrenia. However, the relationship between stress exposure and reelin expression remains unclear. We therefore treated adolescent reelin heteroyzogous mice (HRM) and wild-type (WT) littermates with the stress hormone, corticosterone (CORT) in their drinking water (25 mg/l) for 3 wk. In adulthood, we measured levels of full-length (FL) reelin and the N-R6 and N-R2 cleavage fragments in the frontal cortex (FC) and dorsal (DH) and ventral (VH) hippocampus. As expected, levels of all reelin forms were approximately 50% lower in HRMs compared to WT. In male mice, CORT treatment significantly decreased FL and N-R2 expression in the FC and N-R2 and N-R6 levels in the DH. This reelin down-regulation was accompanied by significant reductions in downstream N-methyl-D-aspartate (NMDA) GluN2C subunit levels. There were no effects of CORT treatment in the VH of either of the sexes and only subtle changes in female DH. CORT-induced reelin and GluN2C down-regulation in males was not associated with changes in two GABAergic neuron markers, GAD67 and parvalbumin, or glucocorticoids receptors (GR). These results show that CORT treatment causes long-lasting and selective reductions of reelin form levels in male FC and DH accompanied by changes in NMDAR subunit composition. This sex-specific reelin down-regulation in regions implicated in schizophrenia could be involved in the effects of stress in this disease.