Maternal stress prior to conception impairs memory and decreases right dorsal hippocampal volume and basilar spine density in the prefrontal cortex of adult male offspring

GR/Ahi1 regulates WDR68-DYRK1A binding and mediates cognitive impairment in prenatally stressed offspring

Accumulating research shows that prenatal exposure to maternal stress increases the risk of behavioral and mental health problems for offspring later in life. However, how prenatal stress affects offspring behavior remains unknown. Here, we found that prenatal stress (PNS) leads to reduced Ahi1, decreased synaptic plasticity and cognitive impairment in offspring. Mechanistically, Ahi1 and GR stabilize each other, inhibit GR nuclear translocation, promote Ahi1 and WDR68 binding, and inhibit DYRK1A and WDR68 binding. When Ahi1 deletion or prenatal stress leads to hyperactivity of the HPA axis, it promotes the release of GC, leading to GR nuclear translocation and Ahi1 degradation, which further inhibits the binding of Ahi1 and WDR68, and promotes the binding of DYRK1A and WDR68, leading to elevated DYRK1A, reduced synaptic plasticity, and cognitive impairment. Interestingly, we identified RU486, an antagonist of GR, which increased Ahi1/GR levels and improved cognitive impairment and synaptic plasticity in PNS offspring. Our study contributes to understanding the signaling mechanisms of prenatal stress-mediated cognitive impairment in offspring.

Stress-Activated Protein Kinase JNK Modulates Depression-like Behaviors in Mice

Stress is considered as a major cause of depression. C-Jun N-terminal kinase (JNK) is a member of the stress-induced mitogen activated protein (MAP) kinase family which is often activated through phosphorylation. Clinical studies and animal experiments have found that abnormal phosphorylation/activation of JNK exists in the occurrence of various psychiatric diseases. Recently, several studies linked JNK kinase activity to depression. However, whether excessive activation of JNK activity is directly responsible for the occurrence of depression and the underlying mechanisms remain unclear. Here, we constructed a conditional transgenic mouse which is specifically expressing MKK7-JNK1 (CAJNK1) in the central nervous system. CAJNK1 mice showed activation of JNK and lead to depression-like behavior in mice. Transcriptome analysis indicates reduced expression of synaptic-associated genes in CAJNK1 mice brains. Consistently, we found abnormal dendritic spine development and PSD95 downregulation in CAJNK1 hippocampal neurons. Our studies provide compelling evidence that activation of JNK as an intrinsic factor leading to depression-like behavior in mice provides direct clues for targeting the JNK activity as a potential therapeutic strategy for depression.

Maternal adverse childhood experiences and infant subcortical brain volume

Background

A large body of research supports the deleterious effects of adverse childhood experiences (ACEs) on disease susceptibility and health for both the exposed individual and the next generation. It is likely that there is an intergenerational transmission of risk from mother to child; however, the mechanisms through which such risk is conferred remain unknown. The current study evaluated the association between maternal ACEs, neonatal brain development of the amygdala and hippocampus, and later infant negative emotionality at six months of age.

Methods

The sample included 85 mother-infant dyads (44 female infants) from a longitudinal study. Maternal ACEs were assessed with the Adverse Childhood Experiences Questionnaire (ACE-Q) and neonatal hippocampal and amygdala volume was assessed using structural magnetic resonance imaging (MRI). Infant negative emotionality was assessed at 6 months using the Infant Behavior Questionnaire (IBQ).

Results

Multivariate analyses demonstrated that maternal ACEs were associated with bilateral amygdala volume (F(2,78) = 3.697,p = .029). Specifically, higher maternal ACEs were associated with smaller left (β = -0.220, t(79) = -2.661, p = .009, R² = 0.494, and right (β = -0.167, t(79) = -2.043, p = .044, R² = 0.501) amygdala volume. No significant association between maternal ACEs and bilateral hippocampal volume (F(2,78) = 0.215,p = .0807) was found. Follow-up regression analyses demonstrated that both high maternal ACEs and smaller left amygdala volume were associated with higher infant negative emotionality at six months of age (β = .232, p = .040, R² = 0.094, and β = -0.337, p = .022, R² = 0.16, respectively) although statistically significant mediation of this effect was not observed (Indirect effect = 0.0187, 95% CI [-0.0016-0.0557]).

Conclusions

Maternal ACEs are associated with both newborn amygdala volume and subsequent infant negative emotionality. These findings linking maternal adverse childhood experiences and infant brain development and temperament provide evidence to support the intergenerational transmission of adversity from mother to child.

Effect of early-life stress or fluoxetine exposure on later-life conditioned taste aversion learning in Sprague-Dawley rats

In rodents, early-life exposure to environmental stress or antidepressant medication treatment has been shown to induce similar long-term consequences on memory- and depression-related behavior in adulthood. To expand on this line of work, we evaluated how juvenile exposure to chronic variable stress (CVS) or the selective serotonin reuptake inhibitor fluoxetine (FLX) influences conditioned taste aversion (CTA) learning in adulthood. To do this, in Experiment 1, we examined how adolescent CVS alone (postnatal day [PND] 35-48), or with prenatal stress (PNS) history (PNS + CVS), influenced the acquisition and extinction of CTA in adult male Sprague Dawley rats. Specifically, at PND70+ (adulthood), rats were presented with 0.15 % saccharin followed by an intraperitoneal (i.p.) injection of lithium chloride (LiCl) to induce visceral malaise. A total of four saccharin (conditioned stimulus) and LiCl (unconditioned stimulus) pairings occurred across the CTA acquisition phase. Next, saccharin was presented without aversive consequences, and intake was measured across consecutive days of the extinction phase. No differences in body weight gain across the experimental days, rate of CTA acquisition, or extinction of CTA, were observed among the experimental groups (control, n = 7; CVS, n = 12; PNS + CVS, n = 9). In Experiment 2, we evaluated if early-life FLX exposure alters CTA learning in adulthood. Specifically, adolescent stress naïve male and female rats received FLX (0 or 20 mg/kg/i.p) once daily for 15 consecutive days (PND35-49). During antidepressant exposure, FLX decreased body weight gain in both male (n = 7) and female rats (n = 7), when compared to respective controls (male control, n = 8; female control, n = 8). However, juvenile FLX exposure decreased body weight-gain in adult male, but not female, rats. Lastly, adolescent FLX history had no effect on CTA acquisition or extinction in adulthood (PND70), in neither male nor female rats. Together, the data indicate that juvenile FLX exposure results in a long-term decrease of body weight-gain in a male-specific manner. Yet, independent of sex, neither early-life stress nor FLX exposure alters CTA learning in adulthood.

Exposure to War Prior to Conception: Maternal Emotional Distress Forecasts Sex-Specific Child Behavior Problems

Objectives: Exposure to maternal stress during the prenatal period adversely affects child outcomes. Recent investigations have shifted to an even earlier period, the preconception period, to better understand the role of this formative period in human health and disease. We investigated the links between maternal emotional distress following preconception exposure to war, and child outcomes at age 10. Material and Methods: Before becoming pregnant, mothers were exposed to missile bombardment on the north of Israel in the 2006 war. Mothers who conceived within 12 months after the war were recruited and compared to mothers who conceived during the same period but lived in Israel but outside missile range. During the initial assessment, mothers completed a questionnaire on emotional distress. At 10 years of age, mothers and children (N = 68) reported on child socio-emotional outcomes. Results: Multiple regression analyses revealed that, in girls, higher maternal emotional distress following preconception war exposure predicted more internalizing and externalizing behavior problems, and more behavior regulation problems. In boys, maternal emotional distress was not significantly related to outcomes. Conclusion: Maternal emotional distress following preconception exposure to war forecasts sex-specific child behavioral problems as reported by the mother and the child. Though the results warrant cautious interpretation because of the relatively small sample size and differential attrition, our findings add to the small but growing body of research on the consequences of maternal stress exposure prior to conception for the next generation.