Disruption of NMDA receptor-mediated regulation of PPI in the maternal immune activation model of schizophrenia is restored by 17ß-estradiol and raloxifene.

Maternal immune activation (MIA) during pregnancy is known to increase the risk of development of schizophrenia in the offspring. Sex steroid hormone analogues have been proposed as potential antipsychotic treatments but the mechanisms of action involved remain unclear. Estrogen has been shown to alter N-methyl-d-aspartate (NMDA) receptor binding in the brain. We therefore studied the effect of chronic treatment with 17ß-estradiol, its isomer, 17α-estradiol, and the selective estrogen receptor modulator, raloxifene, on MIA-induced psychosis-like behaviour and the effect of the NMDA receptor antagonist, MK-801. Pregnant rats were treated with saline or the viral mimetic, poly(I:C), on gestational day 15. Adult female offspring were tested for changes in baseline prepulse inhibition (PPI) and the effects of acute treatment with MK-801 on PPI and locomotor activity. Poly(I:C) offspring had significantly lower baseline PPI compared to control offspring, and this effect was prevented by 17ß-estradiol and raloxifene, but not 17α-estradiol. MK-801 reduced PPI in control offspring but had no effect in poly(I:C) offspring treated with vehicle. Chronic treatment with 17ß-estradiol and raloxifene restored the effect of MK-801 on PPI. There were no effects of MIA or estrogenic treatment on MK-801 induced locomotor hyperactivity. These results show that MIA affects baseline PPI as well as NMDA receptor-mediated regulation of PPI in female rats, and strengthen the view that estrogenic treatment may have antipsychotic effects.

Sex differences in neuronal oscillatory activity and memory in the methylazoxymethanol acetate model of schizophrenia.

The methylazoxymethanol acetate (MAM) rodent model is used to study aspects of schizophrenia. However, numerous studies that have employed this model have used only males, resulting in a dearth of knowledge on sex differences in brain function and behaviour. The purpose of this study was to determine whether differences exist between male and female MAM rats in neuronal oscillatory function within and between the prefrontal cortex (PFC), ventral hippocampus (vHIP) and thalamus, behaviour, and in proteins linked to schizophrenia neuropathology. We showed that female MAM animals exhibited region-specific alterations in theta power, elevated low and high gamma power in all regions, and elevated PFC-thalamus high gamma coherence. Male MAM rats had elevated beta and low gamma power in PFC, and elevated vHIP-thalamus coherence. MAM females displayed impaired reversal learning whereas MAM males showed impairments in spatial memory. Glycogen synthase kinase-3 (GSK-3) was altered in the thalamus, with female MAM rats displaying elevated GSK-3α phosphorylation. Male MAM rats showed higher expression and phosphorylation GSK-3α, and higher expression of GSK-ß. Sex-specific changes in phosphorylated Tau levels were observed in a region-specific manner. These findings demonstrate there are notable sex differences in behaviour, oscillatory network function, and GSK-3 signaling in MAM rats, thus highlighting the importance of inclusion of both sexes when using this model to study schizophrenia.

Particulate matter (PM10) exacerbates on MK-801-induced schizophrenia-like behaviors through the inhibition of ERK-CREB-BDNF signaling pathway.

Particulate matter (PM), released into the air by a variety of natural and human activities, is a key indicator of air pollution. Although PM is known as the extensive health hazard to affect a variety of illness, few studies have specifically investigated the effects of PM10 exposure on schizophrenic development. In the present study, we aimed to investigate the impact of PM10 on MK-801, N-methyl-D-aspartate (NMDA) receptor antagonist, induced schizophrenia-like behaviors in C57BL/6 mouse. Preadolescent mice were exposed PM10 to 3.2 mg/m3 concentration for 4 h/day for 2 weeks through a compartmentalized whole-body inhalation chamber. After PM10 exposure, we conducted behavioral tests during adolescence and adulthood to investigate longitudinal development of schizophrenia. We found that PM10 exacerbated schizophrenia-like behavior, such as psychomotor agitation, social interaction deficits and cognitive deficits at adulthood in MK-801-induced schizophrenia animal model. Furthermore, the reduced expression levels of brain-derived neurotrophic factor (BDNF) and the phosphorylation of BDNF related signaling molecules, extracellular signal-regulated kinase (ERK) and cAMP response element-binding protein (CREB), were exacerbated by PM10 exposure in the adult hippocampus of MK-801-treated mice. Thus, our present study demonstrates that exposure to PM10 in preadolescence exacerbates the cognitive impairment in animal model of schizophrenia, which are considered to be facilitated by the decreased level of BDNF through reduced ERK-CREB expression.

Clinical experiences of guided tapering of antipsychotics for patients with schizophrenia- a case series.

BACKGROUND: 80% of patients value information on treatment options as an important part of recovery, further patients with a history of psychotic episodes feel excluded from decision making about their antipsychotic treatment, and on top of that, mental health staff is prone to be reluctant to support shared decision making and medication tapering for patients with schizophrenia. This case series aims to demonstrate the tapering of antipsychotic medication and how guided tapering affects the patient's feeling of autonomy and psychiatric rehabilitation. CASE PRESENTATION: We present six patients diagnosed with schizophrenia (International Classification of Mental and Behavioral Disorders- 10th Edition codes F20.0-5, F20.7-9) who underwent professionally guided tapering in our clinic. The clinic aims to guide the patients to identify the lowest possible dose of antipsychotic medication in a safe setting to minimise the risk of severe relapse. Two patients completely discontinued their antipsychotic medication, two suffered a relapse during tapering, one chose to stop the tapering at a low dose, and one patient with treatment resistant schizophrenia, which is still tapering down. CONCLUSIONS: Reducing the antipsychotic dose increased emotional awareness in some patients (n = 4) helping them to develop better strategies to handle stress and increased feelings of recovery. Patients felt a greater sense of autonomy and empowerment during the tapering process, even when discontinuation was not possible. Increased awareness in patients and early intervention during relapse may prevent severe relapse. IMPACT AND IMPLICATIONS: Some patients with schizophrenia might be over medicated, leading to unwanted side effects and the wish to reduce their medication. The patients in our study illustrate how guided tapering of antipsychotic medication done jointly with the patient can lead to improved emotional awareness and the development of effective symptom management strategies. This may in turn lead to a greater sense of empowerment and identity and give life more meaning, supporting the experience of personal recovery.

Chronic MK-801 administration provokes persistent deficits in social memory in the prairie vole (Microtus ochrogaster): A potential animal model for social deficits of schizophrenia.

The prairie vole (Microtus ochrogaster) is a rodent species that has been used extensively to study biological aspects of human social bonding. Nevertheless, this species has not been studied in the context of modeling social deficits characteristic of schizophrenia. Building on studies in rodents that show that sub-chronic administration of an NMDA receptor antagonist induces persistent behavioral and neurological characteristics of schizophrenia, we administered MK-801 (0.2 mg/kg, daily, for 7 days) or physiological saline to young adult (45 days old) virgin male voles. At 69 days of age, we paired these males with virgin females. 24 h later, we assessed the males' social investigation of each female across the first 5 min of a three-hour preference test, and side-by-side contact with each female during the last hour of the test. Unlike saline-treated males, MK-801-treated males did not preferentially investigate the unfamiliar female, indicating a deficit in social memory. Although males of both groups preferentially spent time with their female partner, regression analysis revealed that deficits in social memory predicted lower partner preference in MK-801-treated males. We interpret these results in the context of recent studies of the natural history of the prairie vole as well as in the context of cognitive deficits in schizophrenia and propose that the social component of episodic memory might influence an individual's capacity to form and maintain long-term social bonds.

Safety and Tolerability of Starting Aripiprazole Lauroxil With Aripiprazole Lauroxil NanoCrystal Dispersion in 1 Day Followed by Aripiprazole Lauroxil Every 2 Months Using Paliperidone Palmitate Monthly as an Active Control in Patients With Schizophrenia: A Post Hoc Analysis of a Randomized Controlled Trial.

Background: Aripiprazole lauroxil (AL) 1064 mg every 2 months following initiation using the AL NanoCrystal Dispersion formulation (ALNCD) plus 30-mg oral aripiprazole was efficacious and well tolerated in a 25-week, randomized, double-blind phase 3 trial in adults with acute schizophrenia. This post hoc analysis further characterized the safety of AL 1064 mg administered every 2 months and that of active control paliperidone palmitate (PP) 156 mg monthly based on occurrence, timing, and severity of adverse events (AEs) associated with antipsychotic medications.Methods: This study was conducted between November 2017 and March 2019. AL or PP was initiated during an inpatient stay of ≥ 2 weeks with transition to outpatient treatment thereafter. Rates of AEs of clinical interest, including injection site reactions (ISRs), motor AEs, sedation, hypotension, prolactin level increase, weight gain, and suicidal ideation/behavior, were summarized through weeks 4, 9, and 25 for each treatment.Results: Of 200 patients who received ≥ 1 dose of study treatment, 99 (49.5%) completed the study (AL, 57%; PP, 43%). Mean (SD) baseline Positive and Negative Syndrome Scale total scores were 94.1 (9.04) and 94.6 (8.41) in the AL and PP treatment groups, respectively. AEs were reported by 69/99 (70%) patients administered AL and 72/101 (71%) administered PP; most AEs were mild or moderate in severity. ISRs (AL, 18.2%; PP, 26.7%) occurred primarily on days 1 and 8. All akathisia/restlessness AEs (AL, 10.1%; PP, 11.9%) occurred during the first 4 weeks; <10% of patients (either treatment) experienced hypotension, sedation, or suicidal ideation/behavior events. Weight gain of ≥ 7% from baseline occurred in 9.3% of AL- and 23.8% of PP-treated patients. Median prolactin concentrations changed by -4.60 and -3.55 ng/mL among AL-treated males and females, respectively, and did not exceed 2 times normal levels in any AL-treated patients. In PP-treated patients, changes were 21.20 and 80.40 ng/mL and concentrations exceeded 2 times normal in 38% and 88% of males and females, respectively.Conclusions: No new early- or late-emerging safety concerns were observed through 25 weeks of treatment with AL 1064 mg every 2 months following initiation using ALNCD plus 30-mg oral aripiprazole. Results were consistent with known safety profiles of AL and PP and support the safety of AL 1064 mg every 2 months initiated using ALNCD plus 30-mg oral aripiprazole.Trial Registration: ClinicalTrials.gov identifier: NCT03345979.

Effect of Lurasidone on Social Functioning in Schizophrenia: Post Hoc Analysis of the JEWEL Study.

Objective: To evaluate the effects of lurasidone on social functioning in schizophrenia over the course of a 6-week, double-blind, placebo-controlled study and a subsequent 12-week open-label extension study.Methods: A total of 478 patients with schizophrenia (per DSM-IV-TR criteria) randomized to either lurasidone 40 mg/d (n = 245) or placebo (n = 233) in the initial 6-week double-blind study (initiated May 2016, completed November 2018) were included in the analysis. Longer-term changes were examined in a sample of 146 patients who received lurasidone, and 141 who received placebo, during the 6-week study and received flexibly dosed (40-80 mg/d) lurasidone during the 12-week extension phase. The 4-item Positive and Negative Syndrome Scale (PANSS) prosocial subscale was used to examine changes in social functioning.Results: At week 6 of the double-blind phase, lurasidone-treated patients had significantly greater improvement on the PANSS prosocial subscale compared to placebo-treated patients (P < .01, effect size at week 6 = 0.33). Significant differences from placebo were also evident at week 2 (P < .05), week 4 (P < .001), and week 5 (P < .01). Across the 12-week extension phase, patients who received lurasidone during both the 6-week double-blind phase and the 12-week open-label phase continued to show successive decreases in scores on the 4-item PANSS prosocial subscale (score change of -3.0 from double-blind baseline to week 6; mean score change of -4.2 from double-blind baseline to week 12 of the extension phase).Conclusions: In patients with schizophrenia treated with lurasidone, social functioning improved relative to placebo during a 6-week double-blind study and continued to improve over the course of 12 weeks of extension treatment with lurasidone. Effects of lurasidone on social functioning appear to be comparable to what has been reported for other atypical antipsychotics.Trial Registration: EudraCT Numbers: 2016-000060-42 and 2016-000061-23.

Radix Bupleuri aqueous extract attenuates MK801-induced schizophrenia-like symptoms in mice: Participation of intestinal flora.

Schizophrenia (SCZ) is a psychotic mental disorder characterized by cognitive, behavioral, and social impairments. However, current pharmacological treatment regimens are subpar in terms of effectiveness. This study aimed to investigate the function of Radix Bupleuri aqueous extract in SCZ in mouse models. The SCZ mouse model was established by MK-801 injection and feeding of Radix Bupleuri aqueous extract or combined antibiotics. Radix Bupleuri aqueous extract significantly improved the aberrant behaviors and neuronal damage in SCZ mice, upregulated SYP and PSD-95 expression and BDNF levels in hippocampal homogenates, down-regulated DA and 5-HT levels, and suppressed microglial activation in SCZ mice. Moreover, Radix Bupleuri aqueous extract improved the integrity of the intestinal tract barrier. The 16 S rRNA sequencing of feces showed that Radix Bupleuri extract modulated the composition of gut flora. Lactobacillus abundance was decreased in SCZ mice and reversed by Radix Bupleuri aqueous extract administration which exhibited a significant negative correlation with IL-6, IL-1ß, DA, and 5-HT, and a significant positive correlation with BDNF levels in hippocampal tissues. The abundance of Parabacteroides and Alloprevotella was increased in SCZ mice. It was reversed by Radix Bupleuri aqueous extract administration, which exhibited a positive correlation with IL-6, IL-1ß, and 5-HT and a negative correlation with BDNF. In conclusion, Radix Bupleuri aqueous extract attenuates the inflammatory response in hippocampal tissues and modulates neurotransmitter levels, exerting its neuroprotective effect in SCZ. Meanwhile, the alteration of intestinal flora may be involved in this process, which is expected to be an underlying therapeutic option in treating SCZ.

Potential impact on mental health in patients with treatment-resistant schizophrenia - clozapine augmentation with long-acting parenteral antipsychotics: a case series.

INTRODUCTION: The rate of pharmacoresistance among in patients diagnosed with schizophrenia is around 30%. Clozapineis the drug of choice for these patients; however, an adequate response to treatment doesn't always occur. One of the possible augmentation approaches, specifically for non-adherent patients, is the administration of long-acting parenteral antipsychotics. Our goal was to evaluate previous experiences of administering a combination of the atypical antipsychotic clozapine and long-acting injectable antipsychotics to pharmacoresistant patients at the Department of Psychiatry the Czech Republic and to assess the safety and effectiveness of such administration. METHODS: A retrospective evaluation of patient case studies was conducted for those who were hospitalized in the Ward for the therapy of Psychotic disorders between 2016 and 2020 and had a medication history of combining clozapine and depot antipsychotics. RESULTS: Over half of the patients had no illness relapses during the observed period. The clinical manifestation of adverse effects from combination therapy appears low in our patient sample, primarily involving mild and pharmacologically manageable side effects (tachycardia). Only one of the cases recorded neutropenia, which led to discontinuation of clozapine; the patient was maintained on long-acting injectable antipsychotics medication. CONCLUSION: From our findings, it can be inferred that augmenting clozapine with depot antipsychotics is a potential therapeutic intervention that pharmacoresistant patients could benefit from. However, it is essential to emphasize that this therapeutic approach should only be administered after carefully considering the patient's existing treatment. It should be strictly individualized based on the treating physician's or clinical pharmacist's sufficient professional experience.

Comparative estimation of the effects of antihypertensive medications on schizophrenia occurrence: a multinational observational cohort study.

BACKGROUND: The association between antihypertensive medication and schizophrenia has received increasing attention; however, evidence of the impact of antihypertensive medication on subsequent schizophrenia based on large-scale observational studies is limited. We aimed to compare the schizophrenia risk in large claims-based US and Korea cohort of patients with hypertension using angiotensin-converting enzyme (ACE) inhibitors versus those using angiotensin receptor blockers (ARBs) or thiazide diuretics. METHODS: Adults aged 18 years who were newly diagnosed with hypertension and received ACE inhibitors, ARBs, or thiazide diuretics as first-line antihypertensive medications were included. The study population was sub-grouped based on age (> 45 years). The comparison groups were matched using a large-scale propensity score (PS)-matching algorithm. The primary endpoint was incidence of schizophrenia. RESULTS: 5,907,522; 2,923,423; and 1,971,549 patients used ACE inhibitors, ARBs, and thiazide diuretics, respectively. After PS matching, the risk of schizophrenia was not significantly different among the groups (ACE inhibitor vs. ARB: summary hazard ratio [HR] 1.15 [95% confidence interval, CI, 0.99-1.33]; ACE inhibitor vs. thiazide diuretics: summary HR 0.91 [95% CI, 0.78-1.07]). In the older subgroup, there was no significant difference between ACE inhibitors and thiazide diuretics (summary HR, 0.91 [95% CI, 0.71-1.16]). The risk for schizophrenia was significantly higher in the ACE inhibitor group than in the ARB group (summary HR, 1.23 [95% CI, 1.05-1.43]). CONCLUSIONS: The risk of schizophrenia was not significantly different between the ACE inhibitor vs. ARB and ACE inhibitor vs. thiazide diuretic groups. Further investigations are needed to determine the risk of schizophrenia associated with antihypertensive drugs, especially in people aged > 45 years.

A Kpna1-deficient psychotropic drug-induced schizophrenia model mouse for studying gene-environment interactions.

KPNA1 is a mediator of nucleocytoplasmic transport that is abundantly expressed in the mammalian brain and regulates neuronal differentiation and synaptic function. De novo mutations in Kpna1 have been identified using genome-wide association studies in humans with schizophrenia; however, it remains unclear how KPNA1 contributes to schizophrenia pathogenesis. Recent studies have suggested a complex combination of genetic and environmental factors that are closely related to psychiatric disorders. Here, we found that subchronic administration of phencyclidine, a psychotropic drug, induced vulnerability and behavioral abnormalities consistent with the symptoms of schizophrenia in Kpna1-deficient mice. Microarray assessment revealed that the expression levels of dopamine d1/d2 receptors, an RNA editing enzyme, and a cytoplasmic dynein component were significantly altered in the nucleus accumbens brain region in a gene-environment (G × E) interaction-dependent manner. Our findings demonstrate that Kpna1-deficient mice may be useful as a G × E interaction mouse model for psychiatric disorders and for further investigation into the pathogenesis of such diseases and disorders.

Therapeutic-like activity of cannabidiolic acid methyl ester in the MK-801 mouse model of schizophrenia: Role for cannabinoid CB1 and serotonin-1A receptors.

Schizophrenia is a psychotic disorder with an increasing prevalence and incidence over the last two decades. The condition presents with a diverse array of positive, negative, and cognitive impairments. Conventional treatments often yield unsatisfactory outcomes, especially with negative symptoms. We investigated the role of prefrontocortical (PFC) N-methyl-D-aspartate receptors (NMDARs) in the pathophysiology and development of schizophrenia. We explored the potential therapeutic effects of cannabidiolic acid (CBDA) methyl ester (HU-580), an analogue of CBDA known to act as an agonist of the serotonin-1A receptor (5-HT1AR) and an antagonist of cannabinoid type 1 receptor (CB1R). C57BL/6 mice were intraperitoneally administered the NMDAR antagonist, dizocilpine (MK-801, .3 mg/kg) once daily for 17 days. After 7 days, they were concurrently given HU-580 (.01 or .05 µg/kg) for 10 days. Behavioural deficits were assessed at two time points. We conducted enzyme-linked immunosorbent assays to measure the concentration of PFC 5-HT1AR and CB1R. We found that MK-801 effectively induced schizophrenia-related behaviours including hyperactivity, social withdrawal, increased forced swim immobility, and cognitive deficits. We discovered that low-dose HU-580 (.01 µg/kg), but not the high dose (.05 µg/kg), attenuated hyperactivity, forced swim immobility and cognitive deficits, particularly in female mice. Our results revealed that MK-801 downregulated both CB1R and 5-HT1AR, an effect that was blocked by both low- and high-dose HU-580. This study sheds light on the potential antipsychotic properties of HU-580, particularly in the context of NMDAR-induced dysfunction. Our findings could contribute significantly to our understanding of schizophrenia pathophysiology and offer a promising avenue for exploring the therapeutic potential of HU-580 and related compounds in alleviating symptoms.

Exploring peripheral biomarkers of response to simvastatin supplementation in schizophrenia.

Schizophrenia is one of the most debilitating mental disorders, and its diagnosis and treatment present significant challenges. Several clinical trials have previously evaluated the effectiveness of simvastatin, a lipid-lowering medication, as a novel add-on treatment for schizophrenia. However, treatment effects varied highly between patients and over time. In the present study, we aimed to identify biomarkers of response to simvastatin in recent-onset schizophrenia patients. To this end, we profiled relevant immune and metabolic markers in patient blood samples collected in a previous clinical trial (ClinicalTrials.gov: NCT01999309) before simvastatin add-on treatment was initiated. Analysed sample types included serum, plasma, resting-state peripheral blood mononuclear cells (PBMCs), as well as PBMC samples treated ex vivo with immune stimulants and simvastatin. Associations between the blood readouts and clinical endpoints were evaluated using multivariable linear regression. This revealed that changes in insulin receptor (IR) levels induced in B-cells by ex vivo simvastatin treatment inversely correlated with in vivo effects on cognition at the primary endpoint of 12 months, as measured using the Brief Assessment of Cognition in Schizophrenia scale total score (standardised ß ± SE = -0.75 ± 0.16, P = 2.2 × 10-4, Q = 0.029; n = 21 patients). This correlation was not observed in the placebo group (ß ± SE = 0.62 ± 0.39, P = 0.17, Q = 0.49; n = 14 patients). The candidate biomarker explained 53.4 % of the variation in cognitive outcomes after simvastatin supplementation. Despite the small sample size, these findings suggest a possible interaction between the insulin signalling pathway and cognitive effects during simvastatin therapy. They also point to opportunities for personalized schizophrenia treatment through patient stratification.

Associations of the Gut Microbiome With Treatment Resistance in Schizophrenia.

Importance: There is growing interest in the role of gut microbiome composition in schizophrenia. However, lifestyle factors are often neglected, and few studies have investigated microbiome composition in treatment-resistant schizophrenia. Objective: To explore associations between the gut microbiome and schizophrenia diagnosis, treatment resistance, clozapine response, and treatment-related adverse effects while adjusting for demographic and lifestyle factors. Design, Setting, and Participants: In this case-control study of adults aged 20 to 63 years, stool samples and data on demographic characteristics, lifestyle, and medication use were collected and gut microbiome measures obtained using shotgun metagenomics. Participants with a schizophrenia diagnosis were referred through psychiatric inpatient units and outpatient clinics. Data were collected for 4 distinct groups: control individuals without a psychiatric diagnosis (past or present), individuals with treatment-responsive schizophrenia taking nonclozapine antipsychotic medications, clozapine-responsive individuals with treatment-resistant schizophrenia, and clozapine-nonresponsive individuals with treatment-resistant schizophrenia. Participants were recruited between November 2020 and November 2021. Control individuals were recruited in parallel through posters and online advertisements and matched for age, sex, and body mass index (BMI) to the individuals with schizophrenia. Participants were excluded if taking antibiotics in the past 2 months, if unable to communicate in English or otherwise follow study instructions, were pregnant or planning to become pregnant, or had any concomitant disease or condition making them unsuited to the study per investigator assessment. Data were analyzed from January 2022 to March 2023. Main Outcomes and Measures: Omics relationship matrices, α and ß diversity, and relative abundance of microbiome features. Results: Data were collected for 97 individuals (71 [74%] male; mean [SD] age, 40.4 [10.3] years; mean [SD] BMI, 32.8 [7.4], calculated as weight in kilograms divided by height in meters squared). Significant microbiome associations with schizophrenia were observed at multiple taxonomic and functional levels (eg, common species: b2, 30%; SE, 13%; adjusted P = .002) and treatment resistance (eg, common species: b2, 27%; SE, 16%; adjusted P = .03). In contrast, limited evidence was found for microbiome associations with clozapine response, constipation, or metabolic syndrome. Significantly decreased microbial richness was found in individuals with schizophrenia compared to control individuals (t95 = 4.25; P < .001; mean [SD] for control individuals, 151.8 [32.31]; mean [SD] for individuals with schizophrenia, 117.00 [36.2]; 95% CI, 18.6-51.0), which remained significant after a covariate and multiple comparison correction. However, limited evidence was found for differences in ß diversity (weighted UniFrac) for schizophrenia diagnosis (permutational multivariate analysis of variance [PERMANOVA]: R2, 0.03; P = .02), treatment resistance (R2, 0.02; P = .18), or clozapine response (R2, 0.04; P = .08). Multiple differentially abundant bacterial species (19) and metabolic pathways (162) were found in individuals with schizophrenia, which were primarily associated with treatment resistance and clozapine exposure. Conclusions and Relevance: The findings in this study are consistent with the idea that clozapine induces alterations to gut microbiome composition, although the possibility that preexisting microbiome differences contribute to treatment resistance cannot be ruled out. These findings suggest that prior reports of microbiome alterations in individuals with chronic schizophrenia may be due to medication or lifestyle factors and that future studies should incorporate these variables in their design and interpretation.

Effects of the PAM of mGluR2, JNJ-46356479, on brain apoptotic protein levels in a mouse model of schizophrenia.

Current treatment for schizophrenia (SZ) ameliorates the positive symptoms, but is inefficient in treating the negative and cognitive symptoms. The SZ glutamatergic dysfunction hypothesis has opened new avenues in the development of novel drugs targeting the glutamate storm, an inducer of progressive neuropathological changes. Positive allosteric modulators of metabotropic glutamate receptor 2 (mGluR2), such as JNJ-46356479 (JNJ), reduce the presynaptic release of glutamate, which has previously been demonstrated to attenuate glutamate- and dopamine-induced apoptosis in human neuroblastoma cell cultures. We hypothesised that JNJ treatment would modify the brain levels of apoptotic proteins in a mouse model of ketamine (KET)-induced schizophrenia. We analysed the levels of proapoptotic (caspase-3 and Bax) and antiapoptotic (Bcl-2) proteins by western blot in the prefrontal cortex and hippocampus of JNJ-treated mice. JNJ attenuated apoptosis in the brain by partially restoring the levels of the antiapoptotic Bcl-2 protein, which is significantly reduced in animals exposed to KET. Additionally, a significant inverse correlation was observed between proapoptotic protein levels and behavioural deficits in the mice. Our findings suggest that JNJ may attenuate brain apoptosis in vivo, as previously described in cell cultures, providing a link between neuropathological deficits and SZ symptomatology.

Relationship between C-reactive protein and antipsychotics levels in schizophrenic patients infected with COVID-19.

In the context of the COVID-19, inflammation emerges as a prominent characteristic. C-reactive protein (CRP) serves as a commonly employed marker for the evaluation of inflammation. This study aimed to examine the correlation between CRP levels and antipsychotic drug concentrations in patients diagnosed with SCZ during the COVID-19 pandemic. A total of 186 SCZ patients were included in this study, which utilized electronic medical records. The collected data encompassed SCZ diagnoses based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria, respiratory symptoms, and treatments. Laboratory assessments involved the measurement of CRP levels and monitoring of blood drug concentrations. The most prevalent symptoms observed in the patient cohort were fever (59.14%), cough (52.15%), fatigue (45.7%), sore throat (46.24%), runny nose (28.49%), and stuffy nose (25.27%). The levels of CRP during the infection period were significantly higher compared to both the prophase and anaphase of infection (all p < 0.001). The serum levels of clozapine, olanzapine, aripiprazole, quetiapine, and risperidone were elevated during the infection period (all p < 0.001). During the anaphase of infection, patients exhibited higher serum levels of clozapine, olanzapine, and risperidone (all p < 0.001) compared to the infection period, but there was no significant change in serum levels of aripiprazole and quetiapine. Multiple regression analysis revealed a statistically significant positive correlation (P < 0.0001) between CRP and clozapine concentration. In light of the COVID-19 pandemic, it is crucial to adjust the dosage based on drug serum concentration to prevent intoxication or adverse drug reactions.

Activation of prefrontal parvalbumin interneurons ameliorates working memory deficit even under clinically comparable antipsychotic treatment in a mouse model of schizophrenia.

One of the critical unmet medical needs in schizophrenia is the treatment for cognitive deficits. However, the neural circuit mechanisms of them remain unresolved. Previous studies utilizing animal models of schizophrenia did not consider the fact that patients with schizophrenia generally cannot discontinue antipsychotic medication due to the high risk of relapse. Here, we used multi-dimensional approaches, including histological analysis of the prelimbic cortex (PL), LC-MS/MS-based in vivo dopamine D2 receptor occupancy analysis for antipsychotics, in vivo calcium imaging, and behavioral analyses of mice using chemogenetics to investigate neural mechanisms and potential therapeutic strategies for working memory deficit in a chronic phencyclidine (PCP) mouse model of schizophrenia. Chronic PCP administration led to alterations in excitatory and inhibitory synapses, specifically in dendritic spines of pyramidal neurons, vesicular glutamate transporter 1 (VGLUT1) positive terminals, and parvalbumin (PV) positive GABAergic interneurons located in layer 2-3 of the PL. Continuous administration of olanzapine, which achieved a sustained therapeutic window of dopamine D2 receptor occupancy (60-80%) in the striatum, did not ameliorate these synaptic abnormalities and working memory deficit in the chronic PCP-treated mice. We demonstrated that chemogenetic activation of PV neurons in the PL, as confirmed by in vivo calcium imaging, ameliorated working memory deficit in this model even under clinically comparable olanzapine treatment which by itself inhibited only PCP-induced psychomotor hyperactivity. Our study suggests that targeting prefrontal PV neurons could be a promising therapeutic intervention for cognitive deficits in schizophrenia in combination with antipsychotic medication.

Behavioral and transcriptional effects of repeated electroconvulsive seizures in the neonatal MK-801-treated rat model of schizophrenia.

RATIONALE: Electroconvulsive therapy (ECT) is an effective treatment modality for schizophrenia. However, its antipsychotic-like mechanism remains unclear. OBJECTIVES: To gain insight into the antipsychotic-like actions of ECT, this study investigated how repeated treatments of electroconvulsive seizure (ECS), an animal model for ECT, affect the behavioral and transcriptomic profile of a neurodevelopmental animal model of schizophrenia. METHODS: Two injections of MK-801 or saline were administered to rats on postnatal day 7 (PN7), and either repeated ECS treatments (E10X) or sham shock was conducted daily from PN50 to PN59. Ultimately, the rats were divided into vehicle/sham (V/S), MK-801/sham (M/S), vehicle/ECS (V/E), and MK-801/ECS (M/E) groups. On PN59, prepulse inhibition and locomotor activity were tested. Prefrontal cortex transcriptomes were analyzed with mRNA sequencing and network and pathway analyses, and quantitative real-time polymerase chain reaction (qPCR) analyses were subsequently conducted. RESULTS: Prepulse inhibition deficit was induced by MK-801 and normalized by E10X. In M/S vs. M/E model, Egr1, Mmp9, and S100a6 were identified as center genes, and interleukin-17 (IL-17), nuclear factor kappa B (NF-κB), and tumor necrosis factor (TNF) signaling pathways were identified as the three most relevant pathways. In the V/E vs. V/S model, mitophagy, NF-κB, and receptor for advanced glycation end products (RAGE) pathways were identified. qPCR analyses demonstrated that Igfbp6, Btf3, Cox6a2, and H2az1 were downregulated in M/S and upregulated in M/E. CONCLUSIONS: E10X reverses the behavioral changes induced by MK-801 and produces transcriptional changes in inflammatory, insulin, and mitophagy pathways, which provide mechanistic insight into the antipsychotic-like mechanism of ECT.

A randomized, prospective, active-controlled study comparing intramuscular long-acting paliperidone palmitate versus oral antipsychotics in patients with schizophrenia at risk of violent behavior.

OBJECTIVE: Paliperidone palmitate (PP) is an effective long-acting antipsychotic injection, but its impact on the behavior of schizophrenia patients with dangerous tendencies requires further investigation. This study aims to explore the effects of long-term antipsychotic treatment on this population in the community. METHODS: This 49-week, randomized controlled trial was conducted across 21 communities in Wuhan and enrolled 134 schizophrenia patients at risk for violent behavior. With a fixed block size of 10, participants were randomly assigned to receive either intramuscular PP 1-month formulation (PP1M) or oral antipsychotic medication (OAP) at a 1:1 ratio. Changes in patients' risk for violent/aggressive behavior, family burden, social, and cognitive functioning were measured using VRAPP, MOAS, PANSS, FBS, PSP, and RBANS scales from baseline to endpoint. Longitudinal data from multiple repeated measures were analyzed using linear mixed-effects models. RESULTS: The study protocol was completed by 77.6% of the patients overall. Significant improvements were observed in the risk assessment scores, MOAS total score, PANSS total score, PSP total score, and FBS total score of patients in the PP1M group from baseline to the end of treatment (all P < 0.05). Importantly, compared to patients in the OAP group, the improvements in these measures were also significantly greater in the PP1M group. Commonly observed AEs, such as hyperprolactinemia (70.3% vs. 62.65%) and muscle tension (45.3% vs. 57.8%), were considered to be the PP-related AEs. Nonetheless, the differences between the two groups did not reach statistical significance, and no new safety concerns emerged. CONCLUSIONS: Our study suggests that PP long-acting injection (LAI) is a safe and effective treatment option for community-dwelling schizophrenia patients with impulsive violence and risky behaviors.