Prenatal ethanol exposure leads to persistent anxiety-like behavior during adulthood indicated by reduced horizontal and vertical exploratory behaviors

Chemogenetic inhibition of prefrontal cortex inputs to dorsal raphe reduces anxiety behaviors in male rat model of fetal alcohol spectrum disorder

Prenatal ethanol exposure (PE) causes Fetal Alcohol Spectrum Disorders (FASD), characterized by cognitive, behavioral, and emotional deficits, including anxiety and depression. PE-induced alteration in the function of dorsal raphe nucleus (DRN) serotonin (5-HT) neurons is thought to be major contributing factor for increased anxiety. However, the precise neuronal circuits involved are unknown. Using electrophysiology, optogenetics, chemogenetics, and behavioral approaches, we find that PE preferentially potentiates medial prefrontal cortex (mPFC) glutamatergic inputs, but not lateral habenula (LHb), to DRN 5-HT neurons projecting to mPFC. Additionally, PE also increases the strength of LHb but not mPFC excitatory inputs to DRN 5-HT neurons projecting to central amygdala (Ce). This input and target selective effect of PE was mediated by a circuit-specific increase in nitric oxide (NO) signaling. Importantly, chemogenetic inhibition of mPFC-DRN neuronal circuit blunted anxiety-like behaviors in PE rats. As such, our results unraveled the DRN neuronal circuitries affected by PE, which gate FASD-induced anxiety-like behaviors.

Environmental enrichment reverses prenatal ethanol exposure-induced attention-deficits in rats

Introduction

There is a high prevalence of fetal alcohol spectrum disorders (FASD) in the US and the world, which is caused by prenatal ethanol exposure (PE). Most individuals with FASD show attention deficit hyperactivity disorder (ADHD) -like symptoms. Using a rat model of FASD, we have successfully demonstrated that moderate and heavy PE leads to persistent attention deficits, including augmented impulsivity and impaired sustained attention. Anxiety is another primary symptom of FASD. Anxiety and ADHD are closely associated in clinical studies. However, the causal relationship between anxiety and ADHD is not clear. In the present study, we used the strategy of environmental enrichment to reduce anxiety after PE in rats and investigated if attention deficits could be ameliorated.

Methods

A 2nd-trimester binge-drinking pattern of heavy PE was used. Environmental enrichment consisted of neonatal handling and postweaning complex housing. Action impulsivity and sustained attention were tested in adult males and females using the 2-choice reaction time task.

Results

The results show environmental enrichment effectively ameliorated action impulsivity and improved sustained attention in male and female PE rats. Action impulsivity was also improved in control rats with environmental enrichment. In addition, environmental enrichment improved the efficiency of obtaining rewards in male and female control but not PE rats. Environmental enrichment altered the pattern of reaction time components, favoring slower movement initiation but faster movement.

Discussion

These observations support that environmental enrichment could be an effective strategy in ameliorating ADHD-like symptoms in FASD. The reduced anxiety could contribute to such an effect.

Anxiety and Depression and Sleep Problems Among Patients with Fetal Alcohol Spectrum Disorders

Background/Objectives: Sleep disturbances are common among children with fetal alcohol spectrum disorders (FASD) and are often accompanied by emotional and behavioral challenges. This study aimed to evaluate the relationship between sleep problems, anxiety, and depressive symptoms in children with FASD. Methods: The study included 90 children aged 7 to 16 years diagnosed with FASD, who were primarily in foster or adoptive care. Participants completed validated psychometric tools, including the Children's Sleep Habits Questionnaire (CSHQ), State Trait Anxiety Inventory for Children (STAIC) and Children's Depression Inventory 2 (CDI 2). Results: Sleep disturbances were significant, with 71.1% of participants scoring above the clinical threshold in CSHQ. State anxiety, measured by STAIC C-1, was positively correlated with specific sleep difficulties, such as bedtime resistance (r = 0.30, p = 0.008) and sleep anxiety (r = 0.31, p = 0.005). However, no correlation was found between trait anxiety (STAIC C-2) and sleep problems. Parent-reported depressive symptoms, measured using CDI 2:P, were strongly associated with general sleep disturbances (r = 0.27, p < 0.011), parasomnias (r = 0.33, p = 0.002) and daytime sleepiness (r = 0.34, p < 0.001). Conclusions: These findings suggest that sleep disturbances in children with FASD are closely related to state anxiety and depressive symptoms. The results emphasize the need for targeted interventions addressing sleep and emotional health in this population. Further research is needed to examine these relationships and their implications for clinical practice.

Prenatal and postnatal cocaine exposure enhances the anxiety- and depressive-like behaviors in rats: An ontogenetic study

BACKGROUND

Prenatal and postnatal exposure to drugs such as cocaine is a public health problem that causes deficits in brain development and function in humans and animals. One of the main effects of prenatal and postnatal cocaine exposure is increased vulnerability to developing the substance use disorder at an early age. Furthermore, the negative emotional states associated with cocaine withdrawal increase the fragility of patients to relapse into drug abuse. In this sense, prenatal and postnatal cocaine exposure enhanced the cocaine- and nicotine-induced locomotor activity and locomotor sensitization, and rats exposed prenatally to cocaine displayed an increase in anxiety- and depressive-like behaviors in adulthood (PND 60-70).

OBJECTIVE

Therefore, the objective of this study was to determine the effect of prenatal and postnatal cocaine exposure on anxiety- and depressive-like behaviors at different ages (30, 60, 90, and 120 days of age) in rats.

METHODS

The study was divided into two stages: prenatal and postnatal. In the prenatal stage, a group of pregnant female Wistar rats was administered daily from GD0 to GD21 cocaine (cocaine pre-exposure group), and another group of pregnant female rats was administered daily saline (saline pre-exposure group). In the postnatal stage, during lactation (PND0 to PND21), pregnant rats received administration of cocaine or saline, respectively. Of the litters resulting from the cocaine pre-exposed and saline pre-exposed pregnant female groups, only the male rats were used for the recording of the anxiety- and depressive-like behaviors at different postnatal ages (30, 60, 90, and 120 days), representative of adolescence, adult, adulthood, and old age.

RESULTS

The study found that prenatal and postnatal cocaine exposure generated age-dependent enhancement in anxiety- and depressive-like behaviors, being greater in older adult (PND 120) rats than in adolescent (PND 30) or adults (PND 60-90) rats.

CONCLUSIONS

This suggests that prenatal and postnatal cocaine exposure increases anxiety- and depressive-like behaviors, which may increase the vulnerability of subjects to different types of drugs in young and adult age.

Selective disruption of mTORC1 and mTORC2 in VTA astrocytes induces depression and anxiety-like behaviors in mice

Dysfunction of the mechanistic target of rapamycin (mTOR) signaling pathway is implicated in neuropsychiatric disorders including depression and anxiety. Most studies have been focusing on neurons, and the function of mTOR signaling pathway in astrocytes is less investigated. mTOR forms two distinct complexes, mTORC1 and mTORC2, with key scaffolding protein Raptor and Rictor, respectively. The ventral tegmental area (VTA), a vital component of the brain reward system, is enrolled in regulating both depression and anxiety. In the present study, we aimed to examine the regulation effect of VTA astrocytic mTOR signaling pathway on depression and anxiety. We specifically deleted Raptor or Rictor in VTA astrocytes in mice and performed a series of behavioral tests for depression and anxiety. Deletion of Raptor and Rictor both decreased the immobility time in the tail suspension test and the latency to eat in the novelty suppressed feeding test, and increased the horizontal activity and the movement time in locomotor activity. Deletion of Rictor decreased the number of total arm entries in the elevated plus-maze test and the vertical activity in locomotor activity. These data suggest that VTA astrocytic mTORC1 plays a role in regulating depression-related behaviors and mTORC2 is involved in both depression and anxiety-related behaviors. Our results indicate that VTA astrocytic mTOR signaling pathway might be new targets for the treatment of psychiatric disorders.

Interleukin-1β and TNF-α are elevated in the amygdala of adult rats prenatally exposed to ethanol

Affective disorders, including anxiety and depression, developed in adult offspring of the mothers who consumed alcohol during pregnancy could be associated with an imbalance in neuroimmune factors in the amygdala (corpus amygdaloideum) resulted in impaired emotional stimulus processing. The aim of this study was to compare the content of cytokines TNF-α, IL-1α, IL-1β, IL-10, and IL-17 in the amygdala of adult female rats exposed to alcohol in utero and control rats. Cytokine levels were evaluated using a multiplex immunoassay system; mRNA expression was investigated using a real-time reverse transcription-polymerase chain reaction (RT-qPCR) assay. Prenatal alcohol exposure led to the increase in the content of TNF-α and IL-1β without significant changes in the mRNA expression level. Our data suggest that ethanol exposure to the fetus during pregnancy can result in long-term alterations in the content of the key neuroinflammatory factors in the amygdala, which in turn can be a risk factor for affective disorders in the adulthood.

The interaction of genetic sex and prenatal alcohol exposure on health across the lifespan

Prenatal alcohol exposure (PAE) can reprogram the development of cells and tissues, resulting in a spectrum of physical and neurobehavioral teratology. PAE immediately impacts fetal growth, but its effects carry forward post-parturition, into adolescence and adulthood, and can result in a cluster of disabilities, collectively termed Fetal Alcohol Spectrum Disorders. Emerging preclinical and clinical research investigating neurological and behavioral outcomes in exposed offspring point to genetic sex as an important modifier of the effects of PAE. In this review, we discuss the literature on sex differences following PAE, with studies spanning the fetal period through adulthood, and highlight gaps in research where sex differences are likely, but currently under-investigated. Understanding how sex and PAE interact to affect offspring health outcomes across the lifespan is critical for identifying the full complement of PAE-associated secondary conditions, and for refining targeted interventions to improve the quality of life for individuals with PAE.