Abstract Subchronic phencyclidine (subPCP) treatment induces schizophrenic-like behavior in rodents, including cognitive deficits and increased locomotor sensitivity towards acute administration of ...PCP. Evidence is accumulating that the gut microbiota (GM) influences behavior through modulation of the microbiota–gut–brain axis, and hence, part of the variation within this animal model may derive from variation in the GM. The aims of this study was to investigate first, the duration of subPCP-induced cognitive impairment in the novel object recognition test, and second, the possible effect of subchronic PCP-treatment on the GM, and the association between the GM and the behavioral parameters. The association was further investigated by antibiotic reduction of the GM. Male Lister Hooded rats were dosed twice daily i.p. with either 5 mg/kg PCP or sterile isotonic saline for seven days followed by a seven-day washout period. Rats were tested in the novel object recognition and the locomotor activity assays immediately after, three weeks after, or six weeks after washout, and the fecal GM was analyzed by high throughput sequencing. Antibiotic- and control-treated rats were tested in the same manner following washout. In conclusion, subPCP-treatment impaired novel object recognition up to three weeks after washout, whereas locomotor sensitivity was increased for at least six weeks after washout. Differences in the core gut microbiome immediately after washout suggested subPCP treatment to alter the GM. GM profiles correlated to memory performance. Administration of ampicillin abolished the subPCP-induced memory deficit. It thus seems reasonable to speculate that the GM influences memory performance, contributing to variation within the model.
Stress during rat gestation can elicit depression-like physiological and behavioral responses in the offspring. However, human clinical depression is more prevalent among females than males. ...Accordingly, we examined how repeated variable prenatal stress (PS) alters rat anxiety- and depression-like behavior as well as circadian patterning of motor activity in both male and female offspring. For this purpose, we exposed pregnant Sprague-Dawley rats to multiple stressors during gestational days 13-21. Subsequently, we monitored locomotor and rearing/climbing activities in home-like cages for 24 h and measured anxiety- (elevated plus maze, EPM) and depression-like (forced swim test, FST) behaviors in the offspring at a young adult age. As a stressful event later in life (in addition to PS) may be needed to actually trigger an episode of clinical depression, half of the animals were exposed to an acute stressor (elevated platform) before EPM testing. Dams exposed to the stressor battery had increased plasma corticosterone levels compared with controls. Male PS offspring displayed changes in locomotor and rearing/climbing activity relative to controls. Additionally, anxiety measures in the EPM were affected in control animals after acute stressor exposure, however, this response was blunted in PS offspring. Moreover, FST immobility, as an indicator of depressive-like behavior, was increased in female but not male PS rats. Altogether, our results identify both sex- and circadian phase-specific effects of PS. These findings indicate that the PS rat model reflects multiple clinical depression characteristics, including elevated female vulnerability.
Clinical depression is accompanied by changes in sleep patterning, which is controlled in a circadian fashion. It is thus desirable that animal models of depression mirror such diurnally-specific ...state alterations, along with other behavioral and physiological changes. We previously found several changes in behavior indicative of a depression-like phenotype in offspring of rats subjected to repeated, variable prenatal stress (PNS), including increased locomotor activity during specific periods of the circadian cycle. We, therefore, investigated whether PNS rats also exhibit alterations in sleep/wakefulness behavior around the change from light-to-dark phase. Control and PNS Sprague-Dawley rats were implanted with electrodes for continuous monitoring of electroencephalic activity used to determine behavioral state. The distribution of slow-wave sleep (SWS), rapid eye movement sleep (REMS) and wakefulness was compared for periods before and after lights were turned off, between baseline conditions and after exposure to an acute stressor. Both REMS and SWS amounts were increased in PNS rats relative to control animals in the beginning of the dark phase. REMS changes were due to an increase in REMS bout number, rather than in bout duration. During this circadian time period, we did not find any sex differences in the state changes. These results indicate that PNS affects baseline sleep patterning in both male and female rats around active-phase onset.
Plasma biomarkers for Alzheimer's disease (AD) diagnosis/stratification are a “Holy Grail” of AD research and intensively sought; however, there are no well-established plasma markers.
A ...hypothesis-led plasma biomarker search was conducted in the context of international multicenter studies. The discovery phase measured 53 inflammatory proteins in elderly control (CTL; 259), mild cognitive impairment (MCI; 199), and AD (262) subjects from AddNeuroMed.
Ten analytes showed significant intergroup differences. Logistic regression identified five (FB, FH, sCR1, MCP-1, eotaxin-1) that, age/APOε4 adjusted, optimally differentiated AD and CTL (AUC: 0.79), and three (sCR1, MCP-1, eotaxin-1) that optimally differentiated AD and MCI (AUC: 0.74). These models replicated in an independent cohort (EMIF; AUC 0.81 and 0.67). Two analytes (FB, FH) plus age predicted MCI progression to AD (AUC: 0.71).
Plasma markers of inflammation and complement dysregulation support diagnosis and outcome prediction in AD and MCI. Further replication is needed before clinical translation.
There has recently been marked progress in identifying genetic risk factors for major depression (MD) and bipolar disorder (BD); however, few systematic efforts have been made to elucidate ...heterogeneity that exists within and across these diagnostic taxa. The Affective disorders, Environment, and Cognitive Trait (AFFECT) study presents an opportunity to identify and associate the structure of cognition and symptom-level domains across the mood disorder spectrum in a prospective study from a diverse US population.Participants were recruited from the 23andMe, Inc research participant database and through social media; self-reported diagnosis of MD or BD by a medical professional and medication status data were used to enrich for mood-disorder cases. Remote assessments were used to acquire an extensive range of phenotypes, including mood state, transdiagnostic symptom severity, task-based measures of cognition, environmental exposures, personality traits. In this paper we describe the study design, and the demographic and clinical characteristics of the cohort. In addition we report genetic ancestry, SNP heritability, and genetic correlations with other large cohorts of mood disorders.A total of 48,467 participants were enrolled: 14,768 with MD, 9864 with BD, and 23,835 controls. Upon enrollment, 47% of participants with MD and 27% with BD indicated being in an active mood episode. Cases reported early ages of onset (mean = 13.2 and 14.3 years for MD and BD, respectively), and high levels of recurrence (78.6% and 84.9% with >5 episodes), psychotherapy, and psychotropic medication use. SNP heritability on the liability scale for the ascertained MD participants (0.19-0.21) was consistent with the high level of disease severity in this cohort, while BD heritability estimates (0.16-0.22) were comparable to reports in other large scale genomic studies of mood disorders. Genetic correlations between the AFFECT cohort and other large-scale cohorts were high for MD but not for BD. By incorporating transdiagnostic symptom assessments, repeated measures, and genomic data, the AFFECT study represents a unique resource for dissecting the structure of mood disorders across multiple levels of analysis. In addition, the fully remote nature of the study provides valuable insights for future virtual and decentralized clinical trials within mood disorders.
PDF
