Time of exposure to social defeat stress during childhood and adolescence and redox dysregulation on long-lasting behavioral changes, a translational study

Apoptosis-induced decline in hippocampal microglia mediates the development of depression-like behaviors in adult mice triggered by unpredictable stress during adolescence

Depression triggered by harmful stress during adolescence is a common problem that can affect mental health. To date, the mechanisms underlying this type of depression remain unclear. One mechanism for the promotion of depression by chronic stress in adulthood is the loss of hippocampal microglia. Since deleterious stress in adolescence also activates microglia, we investigated the dynamic changes of microglia in the hippocampus in mice exposed to chronic unpredictable stress (CUS) in adolescence. Our results showed that 12 days of CUS stimulation in adolescence induced typical depression-like behaviors in adult mice, which were accompanied by a significant decrease and dystrophy of microglia in the dentate gyrus of the hippocampus. Further analysis showed that this decrease in microglia was mediated by the initial response of microglia to unpredictable stress in the dentate gyrus of the hippocampus and their subsequent apoptosis. Blocking the initial response of microglia to unpredictable stress by pretreatment with minocycline was able to prevent apoptosis and microglial decline as well as the development of depression-like behaviors in adult mice induced by adolescent CUS. Moreover, administration of lipopolysaccharide (LPS) or macrophage-colony stimulatory factor (M-CSF), two drugs that reversed microglia decline in the dentate gyrus, ameliorated the depression-like behaviors induced by CUS stimulation in adolescence. These findings reveal a novel mechanism for the development of depression-like behaviors in animals triggered by deleterious stress in adolescence and suggest that reversing microglial decline in the hippocampus may be a hopeful strategy for the treatment of depression triggered by deleterious stress in adolescence.

Exploratory study evaluating the relationships between perinatal adversity, oxidative stress, and infant neurodevelopment across the first year of life

Early childhood adversity increases risk for negative lifelong impacts on health and wellbeing. Identifying the risk factors and the associated biological adaptations early in life is critical to develop scalable early screening tools and interventions. Currently, there are limited, reliable early childhood adversity measures that can be deployed prospectively, at scale, to assess risk in pediatric settings. The goal of this two-site longitudinal study was to determine if the gold standard measure of oxidative stress, F2-Isoprostanes, is potentially a reliable measure of a physiological response to adversity of the infant and mother. The study evaluated the independent relationships between F2-Isoprostanes, perinatal adversity and infant neurocognitive development. The study included mother-infant dyads born >36 weeks' gestation. Maternal demographic information and mental health assessments were utilized to generate a perinatal cumulative risk score. Infants' development was assessed at 6 and 12 months and both mothers and infants were assayed for F2-isoprostane levels in blood and urine, respectively. Statistical analysis revealed that cumulative risk scores correlated with higher maternal (p = 0.01) and infant (p = 0.05) F2-isoprostane levels at 6 months. Infant F2-isoprostane measures at 2 months were negatively associated with Mullen Scales of Early Learning Composite scores at 12 months (p = 0.04). Lastly, higher cumulative risk scores predicted higher average maternal F2-isoprostane levels across the 1-year study time period (p = 0.04). The relationship between perinatal cumulative risk scores and higher maternal and infant F2-isoprostanes at 6 months may reflect an oxidative stress status that informs a sensitive period in which a biomarker can be utilized prospectively to reveal the physiological impact of early adversity.

Correlation between childhood trauma experience and depressive symptoms among young adults: The potential mediating role of loneliness

BACKGROUND

It is widely recognized that childhood trauma poses a significant risk of developing depressive symptoms. However, the underlying mediation mechanism between childhood trauma and depressive symptoms requires further exploration.

OBJECTIVE

This study focuses on exploring whether loneliness may act as a potential mediator between childhood trauma and depressive symptoms.

PARTICIPANTS AND SETTING

We analyzed a large sample of college students (N = 7293). Participants completed online questionnaires in the WeChat group.

METHODS

Childhood trauma, depressive symptoms, and loneliness were evaluated using the Childhood Trauma Questionnaire-Short Form (CTQ-SF), the Patient Health Questionnaire-9 (PHQ-9), and the University of California Los Angeles Loneliness Scale (UCLA-LS) respectively. The linear regression method was applied to explore the mediating role.

RESULTS

Gender, relationship with family, and left-behind experience are all substantial depressive symptoms risk factors. Childhood trauma was shown to be highly related to depressive symptoms, and this relationship was potentially mediated by loneliness.

CONCLUSIONS

Our research indicates that treating loneliness in those who have undergone childhood trauma may help prevent or treat depressive symptoms. Therefore, loneliness should be taken into consideration while treating and preventing depressive symptoms.

Adverse childhood experiences in patients with schizophrenia: related factors and clinical implications

The relationship between adverse childhood experiences (ACEs) and the development of psychotic symptoms is not well understood. Therefore, this study aimed to investigate the frequency and distribution of ACEs among patients with schizophrenia and their potential correlation with symptomatology and personality pathology. We conducted a cross-sectional study involving 571 patients with schizophrenia in Shanghai, China. Symptomatology was assessed using the Positive and Negative Symptoms Scale (PANSS) and personality pathology was assessed using the Personality Diagnostic Questionnaire Fourth Edition Plus (PDQ-4+). ACEs were assessed using the Child Trauma Questionnaire-Short Form (CTQ-SF). ACEs were highly prevalent, with 80.8% of the patients with schizophrenia reporting at least one ACE. The three most common types of ACE were physical neglect (69.8%), emotional neglect (28.2%), and emotional abuse (22.9%). For specific ACE, emotional abuse was significantly associated with PD traits, whereas emotional and physical neglect types of ACE was significantly associated with negative symptoms. A higher level of physical abuse was more commonly reported by men, younger individuals, and those with a higher level of antisocial PD traits. Higher levels of physical neglect were associated with more severe negative symptoms. ACEs are commonly observed in patients with schizophrenia. Therefore, it is strongly recommended that this clinical population be provided with a comprehensive assessment and individualized intervention for those exposed to specific ACEs.

Oleoylethanolamide restores stress-induced prepulse inhibition deficits and modulates inflammatory signaling in a sex-dependent manner

RATIONALE

Social stress contributes to the development of depressive and anxiety symptomatology and promotes pro-inflammatory signaling in the central nervous system. In this study, we explored the effects of a lipid messenger with anti-inflammatory properties - oleoylethanolamide (OEA) - on the behavioral deficits caused by social stress in both male and female mice.

METHODS

Adult mice were assigned to an experimental group according to the stress condition (control or stress) and treatment (vehicle or OEA, 10 mg/kg, i.p.). Male mice in the stress condition underwent a protocol consisting of four social defeat (SD) encounters. In the case of female mice, we employed a procedure of vicarious SD. After the stress protocol resumed, anxiety, depressive-like behavior, social interaction, and prepulse inhibition (PPI) were assessed. In addition, we characterized the stress-induced inflammatory profile by measuring IL-6 and CX3CL1 levels in the striatum and hippocampus.

RESULTS

Our results showed that both SD and VSD induced behavioral alterations. We found that OEA treatment restored PPI deficits in socially defeated mice. Also, OEA affected differently stress-induced anxiety and depressive-like behavior in male and female mice. Biochemical analyses showed that both male and female stressed mice showed increased levels of IL-6 in the striatum compared to control mice. Similarly, VSD female mice exhibited increased striatal CX3CL1 levels. These neuroinflammation-associated signals were not affected by OEA treatment.

CONCLUSIONS

In summary, our results confirm that SD and VSD induced behavioral deficits together with inflammatory signaling in the striatum and hippocampus. We observed that OEA treatment reverses stress-induced PPI alterations in male and female mice. These data suggest that OEA can exert a buffering effect on stress-related sensorimotor gating behavioral processing.