The prevalence of neurodevelopmental disorders in children prenatally exposed to antiepileptic drugs

Balancing efficacy and safety: The dual impact of antiseizure medications on the developing brain

The number of neurons in the developing brain is greater than typically found in adulthood, and the brain possesses delicate mechanisms to induce the death of excess cells and refine neural circuitry. The correct tuning between the processes of neuronal death and survival generates a mature and functional brain in its complexity and plastic capacity. Epilepsy is a highly prevalent neurological condition worldwide, including among young individuals. However, exposure to the main treatment approaches, the long-term use of Antiseizure Medication (ASM), during the critical period of development can induce a series of changes in this delicate balance. Acting by various mechanisms of action, ASMs may induce an increase in neuronal death, something that translates into deleterious neuropsychiatric effects in adulthood. Several investigations conducted in recent years have brought to light new aspects related to this dynamic, yet many questions, such as the cellular mechanisms of death and the pathophysiology of late effects, still have unresolved elements. In this review, we aimed to explore the mechanisms of action of the most widely used ASMs in the treatment of neonatal epilepsy, the broad aspects of neuronal death in the developing brain and the repercussions of this death and other effects in adulthood. We review the evidence indicating a relationship between exposure to ASMs and the manifestation of associated psychiatric comorbidities in adulthood and discuss some possible mechanisms underlying the induction of this process by morphological and physiological changes in the related behaviors.

Prenatal Exposure to Lipopolysaccharide or Valproate Leads to Abnormal Accumulation of the NMDA Receptor Agonist D-Aspartate in the Adolescent Rat Brain

Autism spectrum disorder (ASD) is a neurodevelopmental psychiatric condition linked to glutamatergic neurotransmission disruption. Although endogenous D-serine and D-aspartate modulate glutamatergic N-methyl D-aspartate receptor (NMDAR) activity, their involvement in ASD remains elusive. We measured the levels of D-aspartate, D-serine, and other key neuroactive amino acids, and their direct precursors in brain regions, plasma, and feces of environmental ASD rat models prenatally exposed to lipopolysaccharide or valproate, both during adolescence and early adulthood, as well as in a genetic ASD model, the Fmr1-Δexon8 rat. No significant changes were found in plasma and feces. Conversely, we observed a prominent accumulation of D-aspartate in several brain regions of lipopolysaccharide- and valproate-exposed rats, selectively during adolescence, while D-serine level variations were more limited. No significant amino acid changes were observed in the Fmr1-Δexon8 rat brain. We also assayed the activity of the main enzymes involved in cerebral D-serine and D-aspartate metabolism, suggesting that their regulation extends beyond their metabolic enzymes. These findings highlight that prenatal environmental stressors disrupt D-amino acid levels selectively in ASD rat brains, emphasizing the role of early NMDAR dysfunction in ASD-related phenotypes.

The Notch Signaling Pathway: A Potential Target for Mental Disorders

The highly conserved Notch signaling pathway plays a critical role in cell fate determination during metazoan development through cell-to-cell communication. The classical pathway consists of Notch receptors, ligands, intracellular effectors, DNA-binding proteins, and other regulatory molecules. Recent research has highlighted its involvement in the pathogenesis of several diseases. In autism, bipolar disorder, and schizophrenia, the Notch signaling pathway is implicated in key processes such as neuronal development and synaptic plasticity. Furthermore, it has been shown to play significant roles in other mental health conditions, including anxiety, depression, post-traumatic stress disorder, and neurocognitive disorders. However, the precise mechanisms underlying the contribution of Notch to these conditions remain poorly understood. This review examines the current understanding of the Notch signaling pathway in mental disorders, highlighting its role in their pathophysiology and summarizing therapeutic strategies aimed at modulating this pathway to improve mental health outcomes.

Association of prenatal exposure to antiseizure medication with risk of autism: a systematic review and meta-analysis

BACKGROUND

Antiseizure medications (ASMs) can affect neurodevelopment and cause congenital malformations. Autism spectrum disorder (ASD) is characterized by challenges in communication, behavior, and learning. This study evaluated the association between prenatal ASM exposure and ASD development.

METHODS

A systematic review and meta-analysis was conducted using PubMed, Scopus, Web of Science, and Cochrane databases to identify studies on fetal ASM exposure and ASD. Hazard ratio (HR) and risk ratio (RR) with 95 % confidence interval (CI) were pooled using a random-effects model. Heterogeneity was assessed using I² statistic. A p-value < 0.05 was considered significant.

RESULTS

10 studies were included in our meta-analysis, comprising 54,747 patients exposed to ASM. Prenatal ASM exposure significantly increased the risk of ASD (HR 1.8082; 95 % CI 1.2616 to 2.5916; P = 0.001; RR 2.0401; 95 % CI 1.7588 to 2.3664; P < 0.0001). Subgroup analyses identified elevated risks with specific ASMs, including carbamazepine (HR 1.2213; 95 % CI 1.0047 to 1.4847; P = 0.045; I² = 0 %), valproate (HR 2.8306; 95 % CI 2.3881 to 3.3550; P < 0.001; I² = 0 %), and oxcarbazepine (HR 1.6141; 95 % CI 1.1500 to 2.2655; P = 0.006; I² = 27 %). Among women with epilepsy, prenatal ASM exposure increased ASD risk (RR 1.4174; 95 % CI 1.2345 to 1.6273; P < 0.0001; I² = 0 %).

CONCLUSIONS

This meta-analysis showed that prenatal exposure to antiseizures, particularly valproate, carbamazepine, and oxcarbazepine, significantly increases ASD risk. These findings emphasize the need for cautious ASM use during pregnancy.

A Narrative Review on the Effect of Valproic Acid on the Placenta

BACKGROUND

Valproic acid (VPA) is an antiepileptic and mood-stabilizing drug with well-established teratogenic risks when taken during pregnancy. While its harmful effects on fetal development are well known, less attention has been given to its impact on placental development and function, despite the placenta's critical role in pregnancy.

AIM

This narrative review examines how VPA exposure affects placental growth, morphology, nutrient transport, and epigenetic modifications. It also considers whether placental dysfunction may contribute VPA's teratogenic effects.

RESULTS

Evidence suggests that VPA disrupts placental structure and growth, alters the expression of nutrient transporters, such as those for folate, glucose, and amino acids, and modifies the placental epigenome, including globally decreased DNA methylation and increased histone acetylation.

DISCUSSION

It is hypothesized that these epigenetic changes may influence chromatin remodelling and trophoblast gene expression, though this connection has not been fully established. Such epigenetic dysregulation may result in aberrant gene expression that underlies the structural and functional impairments observed in the placenta, potentially compromising its ability to support fetal development and contributing to VPA's teratogenic effects. Findings across studies, however, are inconsistent, varying with dose, timing of exposure, and model system. Furthermore, there is a lack of research examining sex-specific differences in placental responses to VPA, despite evidence that male and female placentas exhibit distinct growth patterns, gene expression profiles, and susceptibilities to environmental insults.

CONCLUSION

Addressing these knowledge gaps through targeted research will improve our understanding of how VPA affects the placenta and its role in teratogenesis.

Practice Guideline From the AAN, AES, and SMFM, Pack AM, Oskoui M, Roberson SW, Donley DK, French J, Gerard EE, Gloss D, Miller WR, Clary HMM, Osmundson SS, McFadden B, Parratt K, Pennell PB, Saade G, Smith DB, Sullivan K, Thomas SV, Tomson T, O’Brien MD, Botchway-Doe K, Silsbee HM, Keezer MR. Teratogenesis, Perinatal, and Neurodevelopmental Outcomes After In Utero Exposure to Antiseizure Medication

This practice guideline provides updated evidence-based conclusions and recommendations regarding the effects of antiseizure medications (ASMs) and folic acid supplementation on the prevalence of major congenital malformations (MCMs), adverse perinatal outcomes, and neuro-developmental outcomes in children born to people with epilepsy of childbearing potential (PWECP). A multidisciplinary panel conducted a systematic review and developed practice recommendations following the process outlined in the 2017 edition of the American Academy of Neurology Clinical Practice Guideline Process Manual. The systematic review includes studies through August 2022. Recommendations are supported by structured rationales that integrate evidence from the systematic review, related evidence, principles of care, and inferences from evidence. The following are some of the major recommendations. When treating PWECP, clinicians should recommend ASMs and doses that optimize both seizure control and fetal outcomes should pregnancy occur, at the earliest possible opportunity preconceptionally. Clinicians must minimize the occurrence of convulsive seizures in PWECP during pregnancy to minimize potential risks to the birth parent and to the fetus. Once a PWECP is already pregnant, clinicians should exercise caution in attempting to remove or replace an ASM that is effective in controlling generalized tonic-clonic or focal-to-bilateral tonic-clonic seizures. Clinicians must consider using lamotrigine, levetiracetam, or oxcarbazepine in PWECP when appropriate based on the patient's epilepsy syndrome, likelihood of achieving seizure control, and comorbidities, to minimize the risk of MCMs. Clinicians must avoid the use of valproic acid in PWECP to minimize the risk of MCMs or neural tube defects (NTDs), if clinically feasible. Clinicians should avoid the use of valproic acid or topiramate in PWECP to minimize the risk of offspring being born small for gestational age, if clinically feasible. To reduce the risk of poor neurodevelopmental outcomes, including autism spectrum disorder and lower IQ, in children born to PWECP, clinicians must avoid the use of valproic acid in PWECP, if clinically feasible. Clinicians should prescribe at least 0.4 mg of folic acid supplementation daily preconceptionally and during pregnancy to any PWECP treated with an ASM to decrease the risk of NTDs and possibly improve neurodevelopmental outcomes in the offspring.

Convergence on CaMK4: A Key Modulator of Autism-Associated Signaling Pathways in Neurons

Although the precise underlying cause(s) of autism spectrum disorder remain unclear, more than 1000 rare genetic variations are associated with the condition. For many people living with profound autism, this genetic heterogeneity has impeded the identification of common biological targets for therapy development for core and comorbid traits that include significant impairments in social communication and repetitive and restricted behaviors. A substantial number of genes associated with autism encode proteins involved in signal transduction and synaptic transmission that are critical for brain development and function. CAMK4 is an emerging risk gene for autism spectrum disorder that encodes the CaMK4 (calcium/calmodulin-dependent protein kinase 4) enzyme. CaMK4 is a key component of a Ca2+-activated signaling pathway that regulates neurodevelopment and synaptic plasticity. In this review, we discuss 3 genetic variants of CAMK4 found in individuals with hyperkinetic movement disorder and comorbid neurological symptoms including autism spectrum disorder that are likely pathogenic with monogenic effect. We also comment on 4 other genetic variations in CAMK4 that show associations with autism spectrum disorder, as well as 12 examples of autism-associated variations in other genes that impact CaMK4 signaling pathways. Finally, we highlight 3 environmental risk factors that impact CaMK4 signaling based on studies of preclinical models of autism and/or clinical cohorts. Overall, we review molecular, genetic, physiological, and environmental evidence that suggest that defects in the CaMK4 signaling pathway may play an important role in a common autism pathogenesis network across numerous patient groups, and we propose CaMK4 as a potential therapeutic target.

Neurobehavioral Outcomes of Children with Antenatal Exposure to Antiseizure Medications

OBJECTIVES

To evaluate the effect of antiepileptic medications prescribed to mothers during pregnancy on the development and behavior of children.

METHODS

From the Kerala Registry of Epilepsy and Pregnancy, 98 children between the ages of 1½ to 2½ y were consecutively chosen. Children of mothers who did not have epilepsy during pregnancy and not exposed to antiseizure medications (ASMs) antenatally were selected as comparator group. Developmental assessment of the children was performed using Developmental Assessment Scale for Indian Infants (DASII) and Receptive-Expressive Emergent Language Scale (REELS). Behavior outcomes were assessed using Child Behavior Checklist.

RESULTS

A significant delay in expressive language skills was seen in children exposed to antiseizure medication with an odds ratio of 2.539 (95% CI 1.10, 5.85, P = 0.026). A delay in expressive language skills was seen in polytherapy with clobazam (odds ratio 6.83; 95% CI 2.17, 21.56, P < 0.001). Also, delay was seen in receptive language skills in the same polytherapy group (odds ratio of 7.333; 95% CI 2.16, 24.92, P < 0.001). There were no statistically significant differences between study and comparative groups in motor and mental quotient domains and behavioral outcomes.

CONCLUSIONS

The finding of speech delay in children exposed to ASMs is significant since individuals with a history of childhood speech or language disorders may experience long-term difficulties in mental health, social well-being, and academic outcomes.

Embryonic exposure to valproic acid and neonicotinoid deteriorates the hyperpolarizing GABA shift and impairs long-term potentiation of excitatory transmission in the local circuit of intermediate medial mesopallium of chick telencephalon

Embryonic exposure to valproic acid and imidacloprid (a neonicotinoid insecticide) impairs filial imprinting in hatchlings, and the deteriorating effects of valproic acid are mitigated by post-hatch injection of bumetanide, a blocker of the chloride intruder Na-K-2Cl cotransporter 1. Here, we report that these exposures depolarized the reversal potential of local GABAergic transmission in the neurons of the intermediate medial mesopallium, the pallial region critical for imprinting. Furthermore, exposure increased field excitatory post-synaptic potentials in pre-tetanus recordings and impaired long-term potentiation (LTP) by low-frequency tetanic stimulation. Bath-applied bumetanide rescued the impaired LTP in the valproic acid slices, whereas VU0463271, a blocker of the chloride extruder KCC2, suppressed LTP in the control slices, suggesting that hyperpolarizing GABA action is necessary for the potentiation of excitatory synaptic transmission. Whereas a steep increase in the gene expression of KCC2 appeared compared to NKCC1 during the peri-hatch development, significant differences were not found between valproic acid and control post-hatch chicks in these genes. Instead, both valproic acid and imidacloprid downregulated several transcriptional regulators (FOS, NR4A1, and NR4A2) and upregulated the RNA component of signal recognition particles (RN7SL1). Despite different chemical actions, valproic acid and imidacloprid could cause common neuronal effects that lead to impaired imprinting.

Prenatal exposure to valproic acid induces sex-specific alterations in rat cortical and hippocampal neuronal structure and function in vitro

There are substantial differences in the characteristics of males and females with an autism spectrum disorder (ASD), yet there is little knowledge surrounding the mechanistic underpinnings of these differences. The valproic acid (VPA) rodent model is based upon the human fetal valproate spectrum disorder, which is associated with increased risk of developing ASD. This model, which displays significant social, learning, and memory alterations, has therefore been widely used to further our understanding of specific biological features of ASD. However, to date, almost all of the studies employing this model have used male rodents. To fill this knowledge gap, we evaluated sex differences for neuronal activity, morphology, and glycogen synthase kinase-3 (GSK-3) signaling in primary cortical (CTX) and hippocampal (HIP) neurons prepared from rats exposed to VPA in utero. In vivo, sex-specific VPA-induced alterations in the frontal CTX transcriptome at birth were also determined. Overall, VPA induced more robust changes in neuronal function and structure in the CTX than in the HIP. Male- and female-derived primary CTX neurons from rats exposed to prenatal VPA had elevated activity and showed more disorganized firing. In the HIP, only the female VPA neurons showed elevated firing, while the male VPA neurons exhibited disorganized activity. Dendritic arborization of CTX neurons from VPA rats was less complex in both sexes, though this was more pronounced in the females. Conversely, both female and male HIP neurons from VPA rats showed elevated complexity distal to the soma. Female VPA CTX neurons also had an elevated number of dendritic spines. The relative activity of the α and β isoforms of GSK-3 were suppressed in both female and male VPA CTX neurons, with no changes in the HIP neurons. On postnatal day 0, alterations in CTX genes associated with neuropeptides (e.g., penk, pdyn) and receptors (e.g., drd1, adora2a) were seen in both sexes, though they were downregulated in females and upregulated in males. Together these findings suggest that substantial sex differences in neuronal structure and function in the VPA model may have relevance to the reported sex differences in idiopathic ASD.

NEAT1 Promotes Valproic Acid-Induced Autism Spectrum Disorder by Recruiting YY1 to Regulate UBE3A Transcription

Evidence suggests that long non-coding RNAs (lncRNAs) play a significant role in autism. Herein, we explored the functional role and possible molecular mechanisms of NEAT1 in valproic acid (VPA)-induced autism spectrum disorder (ASD). A VPA-induced ASD rat model was constructed, and a series of behavioral tests were performed to examine motor coordination and learning-memory abilities. qRT-PCR and western blot assays were used to evaluate target gene expression levels. Loss-and-gain-of-function assays were conducted to explore the functional role of NEAT1 in ASD development. Furthermore, a combination of mechanistic experiments and bioinformatic tools was used to assess the relationship and regulatory role of the NEAT1-YY1-UBE3A axis in ASD cellular processes. Results showed that VPA exposure induced autism-like developmental delays and behavioral abnormalities in the VPA-induced ASD rat model. We found that NEAT1 was elevated in rat hippocampal tissues after VPA exposure. NEAT1 promoted VPA-induced autism-like behaviors and mitigated apoptosis, oxidative stress, and inflammation in VPA-induced ASD rats. Notably, NEAT1 knockdown improved autism-related behaviors and ameliorated hippocampal neuronal damage. Mechanistically, it was observed that NEAT1 recruited the transcription factor YY1 to regulate UBE3A expression. Additionally, in vitro experiments further confirmed that NEAT1 knockdown mitigated hippocampal neuronal damage, oxidative stress, and inflammation through the YY1/UBE3A axis. In conclusion, our study demonstrates that NEAT1 is highly expressed in ASD, and its inhibition prominently suppresses hippocampal neuronal injury and oxidative stress through the YY1/UBE3A axis, thereby alleviating ASD development. This provides a new direction for ASD-targeted therapy.

Brain region-specific neural activation by low-dose opioid promotes social behavior

The opioid system plays crucial roles in modulating social behaviors in both humans and animals. However, the pharmacological profiles of opioids regarding social behavior and their therapeutic potential remain unclear. Multiple pharmacological, behavioral, and immunohistological c-Fos mapping approaches were used to characterize the effects of μ-opioid receptor agonists on social behavior and investigate the mechanisms in naive mice and autism spectrum disorder-like (ASD-like) mouse models, such as prenatally valproic acid-treated mice and Fmr1-KO mice. Here, we report that low-dose morphine, a μ-opioid receptor agonist, promoted social behavior by selectively activating neurons in prosocial brain regions, including the nucleus accumbens, but not those in the dorsomedial periaqueductal gray (dmPAG), which are only activated by analgesic high-dose morphine. Critically, intra-dmPAG morphine injection counteracted the prosocial effect of low-dose morphine, suggesting that dmPAG neural activation suppresses social behavior. Moreover, buprenorphine, a μ-opioid receptor partial agonist with less abuse liability and a well-established safety profile, ameliorated social behavior deficits in two mouse models recapitulating ASD symptoms by selectively activating prosocial brain regions without dmPAG neural activation. Our findings highlight the therapeutic potential of brain region-specific neural activation induced by low-dose opioids for social behavior deficits in ASD.

TAAR1 and 5-HT1B receptor agonists attenuate autism-like irritability and aggression in rats prenatally exposed to valproic acid

Despite the rising prevalence of autism spectrum disorder (ASD), there remains a significant unmet need for pharmacotherapies addressing its core and associative symptoms. While some atypical antipsychotics have been approved for managing associated irritability and aggression, their use is constrained by substantial side effects. This study aimed firstly to develop behavioral measures to explore frustration, irritability and aggression phenotypes in the rat prenatal valproic acid (VPA) model of ASD. Additionally, we investigated the potential of two novel mechanisms, 5-HT1B and TAAR1 agonism, to alleviate these behaviors. Male offspring exposed to prenatal VPA were trained to achieve stable performance on a cued operant task, followed by pharmacological assessment in an operant frustration test, bottle brush test and resident intruder test. VPA exposed rats demonstrated behaviors indicative of frustration and irritability, as well as increased aggression compared to controls. The irritability-like behavior and aggression were further exacerbated in animals previously experiencing a frustrative event during the operant test. Single administration of the 5-HT1B agonist CP-94253 or TAAR1 agonist RO5263397 attenuated the frustration-like behavior compared to vehicle. Additionally, both agonists reduced irritability-like behavior under both normal and frustrative conditions. While CP-94253 reduced aggression in the resident intruder test under both conditions, RO5263397 only produced effects in rats that previously experienced a frustrative event. Our study describes previously uncharacterized phenotypes of frustration, irritability, and aggression in the rat prenatal VPA model of ASD. Administration of selective TAAR1 or 5-HT1B receptor agonists alleviated these deficits, warranting further exploration of both targets in ASD treatment.

Antiseizure medication use during pregnancy and children's neurodevelopmental outcomes

The teratogenic potential of valproate in pregnancy is well established; however, evidence regarding the long-term safety of other antiseizure medications (ASMs) during pregnancy remains limited. Using routinely collected primary care data from the UK and nationwide Swedish registries to create a cohort of 3,182,773 children, of which 17,495 were exposed to ASMs in pregnancy, we show that those exposed to valproate were more likely to receive a diagnosis of autism, intellectual disability, and ADHD, when compared to children not exposed to ASMs. Additionally, children exposed to topiramate were 2.5 times more likely to be diagnosed with intellectual disability (95% CI: 1.23-4.98), and those exposed to carbamazepine were 1.25 times more likely to be diagnosed with autism (95% CI: 1.05-1.48) and 1.30 times more likely to be diagnosed with intellectual disability (95% CI: 1.01-1.69). There was little evidence that children exposed to lamotrigine in pregnancy were more likely to receive neurodevelopmental diagnoses. While further research is needed, these findings may support considering safer treatment alternatives well before conception when clinically appropriate.

Impaired brainstem auditory evoked potentials after in utero exposure to high dose paracetamol exposure

Paracetamol is an analgesic and antipyretic medication regarded as the safest over-the-counter pain and fever relief option during pregnancy. Paracetamol and its metabolites are known to reach the developing fetus through direct placental transfer and can cross the blood brain barrier. Several recent, large-scale epidemiologic studies suggest that in utero paracetamol exposure can increase the risk of neurodevelopmental conditions, including autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD) and developmental delay (DD). Since auditory processing deficits are a common feature of ASD, we hypothesized that animals exposed to paracetamol in utero will have impaired auditory brainstem function. We investigated this hypothesis by recording and analyzing click-evoked auditory brainstem responses (ABR) at postnatal day 21 and 29 in Sprague-Dawley rats. In utero exposure to high dose paracetamol exposure had no impact on body or brain weight. However, high dose paracetamol exposure did significantly delay ear opening and resulted in elevated ABR thresholds, and longer wave and interwave latencies. These changes in wave latency extended to the highest click intensity tested but were most severe near threshold. This data suggests that development and function of the auditory brainstem may be impacted by high dose paracetamol exposure and that simple, non-invasive tests of auditory function have utility as an early screening tool for neurodevelopmental disorders.

Soluble form of Lingo2, an autism spectrum disorder-associated molecule, functions as an excitatory synapse organizer in neurons

Autism Spectrum Disorder (ASD) is a developmental disorder characterized by impaired social communication and repetitive behaviors. In recent years, a pharmacological mouse model of ASD involving maternal administration of valproic acid (VPA) has become widely used. Newborn pups in this model show an abnormal balance between excitatory and inhibitory (E/I) signaling in neurons and exhibit ASD-like behavior. However, the molecular basis of this model and its implications for the pathogenesis of ASD in humans remain unknown. Using quantitative secretome analysis, we found that the level of leucine-rich repeat and immunoglobulin domain-containing protein 2 (Lingo2) was upregulated in the conditioned medium of VPA model neurons. This upregulation was associated with excitatory synaptic organizer activity. The secreted form of the extracellular domain of Lingo2 (sLingo2) is produced by the transmembrane metalloprotease ADAM10 through proteolytic processing. sLingo2 was found to induce the formation of excitatory synapses in both mouse and human neurons, and treatment with sLingo2 resulted in an increased frequency of miniature excitatory postsynaptic currents in human neurons. These findings suggest that sLingo2 is an excitatory synapse organizer involved in ASD, and further understanding of the mechanisms by which sLingo2 induces excitatory synaptogenesis is expected to advance our understanding of the pathogenesis of ASD.

Obliteration of a glycinergic projection to the medial geniculate in an animal model of autism

Auditory dysfunction affects the vast majority of people with autism spectrum disorder (ASD) and can range from deafness to hypersensitivity. In utero exposure to the antiepileptic valproic acid (VPA) is associated with significant risk of an ASD diagnosis in humans and timed in utero exposure to VPA is utilized as an animal model of ASD. VPA-exposed rats have significantly fewer neurons in their auditory brainstem, thalamus and cortex, reduced ascending projections to the midbrain and thalamus and reduced descending projections from the cortex to the auditory midbrain. Consistent with these anatomical changes, VPA-exposed animals also have abnormal auditory brainstem responses. We have recently described a significant ascending projection from calbindin-positive neurons in the medial nucleus of the trapezoid body (MNTB) to the ventral division of the medial geniculate (vMG) in rats that bypasses the central nucleus of the inferior colliculus (CNIC). Since we found that axonal projections to the vMG in VPA-exposed rats are reduced beyond what is predicted from neuron loss alone, we hypothesize that VPA exposure would result in a significant reduction in the MNTB projection to the vMG. We examined this hypothesis by quantifying the proportion of retrogradely-labeled neurons in the MNTB of control and VPA-exposed animals after injections of retrograde tracers in the CNIC and vMG in control and VPA-exposed animals. Our results indicate that in control animals, the MNTB forms the largest projection from the superior olivary complex to the MG and that this projection is nearly abolished by in utero VPA exposure.

Morbidity and mortality risks associated with valproate withdrawal in young adults with epilepsy

Valproate is the most effective treatment for idiopathic generalized epilepsy. Current guidance precludes its use in females of childbearing potential, unless other treatments are ineffective or not tolerated, because of high teratogenicity. This risk was recently extended to males. New guidance will limit use both in males and females aged <55 years, resulting in withdrawal of valproate from males already taking it, as occurs for females. Whether there are risks of personal harm (including injury or death) associated with valproate withdrawal has not yet been quantified for males or females ON valproate, meaning clinicians cannot reliably counsel either sex when discussing valproate withdrawal with them, despite that this concern may be at the forefront of patients' and clinicians' minds. We assessed whether there are any morbidity or mortality risks associated with valproate withdrawal in young males and females. We performed a retrospective cohort study of internationally derived electronic health data within the TriNetX Global Collaborative Network. Included were males and females aged 16-54 years with ≥1 epilepsy disease or symptom code between 1 December 2017 and 1 December 2018, and ≥2 valproate prescriptions over the preceding 2 years (1 January 2015-30 November 2017). Five-year propensity-matched risks of mortality and a range of morbidity outcomes were compared between those remaining ON versus withdrawn from valproate during the 1 December 2017-1 December 2018 recruitment period, regardless of whether switched to another antiseizure medication. Survival analysis was undertaken using Cox-proportional hazard models, generating hazard ratios (HRs) with 95% confidence intervals (CIs). In total, 8991 males and 5243 females taking valproate were recruited. Twenty-eight per cent of males and 36% of females were subsequently withdrawn from valproate. Valproate withdrawal was associated with significantly increased risks of emergency department attendance [HRs overall: 1.236 (CI 1.159-1.319), males: 1.181 (CI 1.083-1.288), females: 1.242 (CI 1.125-1.371)], hospital admission [HRs overall: 1.160 (CI 1.081-1.246), males: 1.132 (CI 1.027-1.249), females: 1.147 (CI 1.033-1.274)], falls [HRs overall: 1.179 (CI 1.041-1.336), males: 1.298 (CI 1.090-1.546)], injuries [HRs overall: 1.095 (CI 1.021-1.174), males: 1.129 (CI 1.029-1.239)], burns [HRs overall: 1.592 (CI 1.084-2.337)] and new-onset depression [HRs overall 1.323 (CI 1.119-1.565), females: 1.359 (CI 1.074-1.720)]. The risk of these outcomes occurring was 1%-7% higher in those withdrawn from valproate than in those remaining ON valproate. Overall, valproate withdrawal was not associated with increased mortality. These results may help patients and clinicians have a more informed discussion about personal safety when considering valproate withdrawal.

Poor neurodevelopment, nutritional and physical growth outcomes among children born to mothers with nodding syndrome

INTRODUCTION

Nodding syndrome (NS), a poorly understood severe neurological disorder develops in children. In Uganda, some NS cases have grown into child-bearing adults. Babies born to mothers with NS may be prone to impaired neurodevelopmental outcomes. Cognitive deficits in mothers with NS may further inhibit care offered to their children hence compromising neurocognitive development, physical growth, and behaviour.

OBJECTIVES

The study aimed to determine the neurodevelopmental, behavioural, nutritional, and physical growth outcomes of children whose mothers have nodding syndrome.

METHODS

A comparative cross-sectional study was conducted between May 2021 and April 2022 in Northern Uganda. Children aged 0-5 years of mothers with NS were compared to those of mothers without NS, matched by age, gender and neighbouring residence. Neurodevelopment, behaviour, nutrition, and physical growth were assessed using standardized measures and t-tests employed for group comparisons of outcomes.

RESULTS

Overall,106 children participated. Fifty-three (53) were offspring of mothers with NS and 53 of mothers without NS; having a mean age of 26.9 (2.22) and 27.5(2.12) months respectively. Children whose mothers have NS had significantly lower neurodevelopmental scores than those of NS-unaffected mothers in fine motor (37.5(12.1) vs 44.2(14.3), p = 0.011), receptive language (37.8(10.8) vs 43.9(12.9), p = 0.010), overall cognitive development (74.36(17.8) vs 83.34(19.6), p = 0.015), and attention (0.64(0.20) vs 0.76(0.15), p = 0.001). There were no differences in the behaviour scores. Children of mothers with NS also had significantly lower weight-for-age z scores (WAZ) (p = 0.003) and length/height-for-age z scores (LAZ/HAZ) (p = 0.001); with 19(35.9 %) of them stunted.

CONCLUSION

Children whose mothers have NS have poorer neurodevelopmental, nutritional, and physical growth outcomes. Interventions to improve outcomes in these children are warranted.

Therapeutic effects of nanosilibinin in valproic acid-zebrafish model of autism spectrum disorder: Focusing on Wnt signaling pathway and autism spectrum disorder-related cytokines

In this study, we delved into the intricate world of autism spectrum disorder (ASD) and its connection to the disturbance in the Wnt signaling pathway and immunological abnormalities. Our aim was to evaluate the impact of silibinin, a remarkable modulator of both the Wnt signaling pathway and the immune system, on the neurobehavioral and molecular patterns observed in a zebrafish model of ASD induced by valproic acid (VPA). Because silibinin is a hydrophobic molecule and highly insoluble in water, it was used in the form of silibinin nanoparticles (nanosilibinin, NS). After assessing survival, hatching rate, and morphology of zebrafish larvae exposed to different concentrations of NS, the appropriate concentrations were chosen. Then, zebrafish embryos were exposed to VPA (1 μM) and NS (100 and 200 μM) at the same time for 120 h. Next, anxiety and inattentive behaviors and the expression of CHD8, CTNNB, GSK3beta, LRP6, TNFalpha, IL1beta, and BDNF genes were assessed 7 days post fertilization. The results indicated that higher concentrations of NS had adverse effects on survival, hatching, and morphological development. The concentrations of 100 and 200 μM of NS could ameliorate the anxiety-like behavior and learning deficit and decrease ASD-related cytokines (IL1beta and TNFalpha) in VPA-treated larvae. In addition, only 100 μM of NS prevented raising the gene expression of Wnt signaling-related factors (CHD8, CTNNB, GSK3beta, and LRP6). In conclusion, NS treatment for the first 120 h showed therapeutic effect on an autism-like phenotype probably via reducing the expression of pro-inflammatory cytokines genes and changing the expression of Wnt signaling components genes.

Prenatal exposure to valproic acid reduces synaptic δ-catenin levels and disrupts ultrasonic vocalization in neonates

Valproic acid (VPA) is an effective and commonly prescribed drug for epilepsy and bipolar disorder. However, children born from mothers treated with VPA during pregnancy exhibit an increased incidence of autism spectrum disorder (ASD). Although VPA may impair brain development at the cellular level, the mechanism of VPA-induced ASD has not been completely addressed. A previous study has found that VPA treatment strongly reduces δ-catenin mRNA levels in cultured human neurons. δ-catenin is important for the control of glutamatergic synapses and is strongly associated with ASD. VPA inhibits dendritic morphogenesis in developing neurons, an effect that is also found in neurons lacking δ-catenin expression. We thus hypothesize that prenatal exposure to VPA significantly reduces δ-catenin levels in the brain, which impairs glutamatergic synapses to cause ASD. Here, we found that prenatal exposure to VPA markedly reduced δ-catenin levels in the brain of mouse pups. VPA treatment also impaired dendritic branching in developing mouse cortical neurons, which was partially reversed by elevating δ-catenin expression. Prenatal VPA exposure significantly reduced synaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor levels and postsynaptic density 95 (PSD95) in the brain of mouse pups, indicating dysfunctions in glutamatergic synaptic transmission. VPA exposure also significantly altered ultrasonic vocalization (USV) in newly born pups when they were isolated from their nest. Moreover, VPA-exposed pups show impaired hypothalamic response to isolation, which is required to produce animals' USVs following isolation from the nest. Therefore, these results suggest that VPA-induced ASD pathology can be mediated by the loss of δ-catenin functions.

VPA-induced autism impairs memory ability through disturbing neural oscillatory patterns in offspring rats

Autism spectrum disorder (ASD) is a general neurodevelopmental disease characterized by unusual social communication and rigid, repetitive behavior patterns. The purpose of this study was to investigate the effects of ASD on the alteration of neural oscillatory patterns and synaptic plasticity, which commonly supported a wide range of basic and higher memory activities. Accordingly, a prenatal valproic acid (VPA) exposure rat model was established for studying autism. The behavioral experiments showed that the social orientation declined and the memory ability was significantly impaired in VPA rats, which was closely associated with the synaptic plasticity deficits. Neural oscillation is the rhythmic neuron-activity, and the pathological characteristics and neurological changes in autism may be peeped at the neural oscillatory analysis. Interestingly, neural oscillatory analysis showed that prenatal VPA exposure reduced the low-frequency power but increased high-frequency gamma (HG) power in the hippocampus CA1 area. Meanwhile, the coherence and synchronization between CA3 and CA1 were abnormally increased in the VPA group, especially in theta and HG rhythms. Furthermore, the cross-frequency coupling strength of theta-LG in the CA1 and CA3 → CA1 pathway was significantly attenuated, but the theta-HG coupling strength was increased. Additionally, prenatal VPA exposure inhibited the expression of SYP and NR2B but enhanced the expression of PSD-95 along with decreased synaptic plasticity. The neural oscillatory patterns in VPA-induced offspring were disturbed with the intensity and direction of neural information flow disordered, which are consistent with the changes in synaptic plasticity, suggesting that the decline in synaptic plasticity is the underlying mechanism.

Exposure to anti-seizure medication during pregnancy and the risk of autism and ADHD in offspring: a systematic review and meta-analysis

Background

Evidence of an association between maternal use of anti-seizure medication (ASM) during pregnancy and the risk of autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD) in children is conflicting. This systematic review and meta-analysis aimed to summarize the relationship between fetal exposure to ASM and the development of ASD or ADHD in offspring.

Methods

A comprehensive literature search was conducted in PubMed and other databases to identify relevant epidemiological studies published from inception until 1 March 2024.

Results

Seven cohort studies were included in the meta-analysis. The results showed that maternal exposure to ASMs during pregnancy was associated with an increased risk of ASD [odds ratio (OR): 2.1, 95% confidence interval (CI): 1.63-2.71; p < 0.001] in the general population. This association became weaker (ASD: OR: 1.38, 95% CI: 1.11-1.73; p = 0.004) when the reference group was mothers with a psychiatric disorder or epilepsy not treated during pregnancy. Furthermore, an increased risk of ADHD was observed when the study data adjusted for drug indications were pooled (OR: 1.43, 95% CI: 1.07-1.92; p = 0.015). In subgroup analyses based on individual ASM use, only exposure to valproate preconception was significantly associated with an increased risk of ASD or ADHD.

Conclusion

The significant association between maternal ASM use during pregnancy and ASD or ADHD in offspring may be partially explained by the drug indication or driven by valproate.

Teratogenesis, Perinatal, and Neurodevelopmental Outcomes After In Utero Exposure to Antiseizure Medication: Practice Guideline From the AAN, AES, and SMFM

This practice guideline provides updated evidence-based conclusions and recommendations regarding the effects of antiseizure medications (ASMs) and folic acid supplementation on the prevalence of major congenital malformations (MCMs), adverse perinatal outcomes, and neurodevelopmental outcomes in children born to people with epilepsy of childbearing potential (PWECP). A multidisciplinary panel conducted a systematic review and developed practice recommendations following the process outlined in the 2017 edition of the American Academy of Neurology Clinical Practice Guideline Process Manual. The systematic review includes studies through August 2022. Recommendations are supported by structured rationales that integrate evidence from the systematic review, related evidence, principles of care, and inferences from evidence. The following are some of the major recommendations. When treating PWECP, clinicians should recommend ASMs and doses that optimize both seizure control and fetal outcomes should pregnancy occur, at the earliest possible opportunity preconceptionally. Clinicians must minimize the occurrence of convulsive seizures in PWECP during pregnancy to minimize potential risks to the birth parent and to the fetus. Once a PWECP is already pregnant, clinicians should exercise caution in attempting to remove or replace an ASM that is effective in controlling generalized tonic-clonic or focal-to-bilateral tonic-clonic seizures. Clinicians must consider using lamotrigine, levetiracetam, or oxcarbazepine in PWECP when appropriate based on the patient's epilepsy syndrome, likelihood of achieving seizure control, and comorbidities, to minimize the risk of MCMs. Clinicians must avoid the use of valproic acid in PWECP to minimize the risk of MCMs or neural tube defects (NTDs), if clinically feasible. Clinicians should avoid the use of valproic acid or topiramate in PWECP to minimize the risk of offspring being born small for gestational age, if clinically feasible. To reduce the risk of poor neurodevelopmental outcomes, including autism spectrum disorder and lower IQ, in children born to PWECP, clinicians must avoid the use of valproic acid in PWECP, if clinically feasible. Clinicians should prescribe at least 0.4 mg of folic acid supplementation daily preconceptionally and during pregnancy to any PWECP treated with an ASM to decrease the risk of NTDs and possibly improve neurodevelopmental outcomes in the offspring.

A case-control study on pre-, peri-, and neonatal risk factors associated with autism spectrum disorder among Armenian children

We aimed to investigate the role of pre-, peri- and neonatal risk factors in the development of autism spectrum disorder (ASD) among Armenian children with the goal of detecting and addressing modifiable risk factors to reduce ASD incidence. For this purpose a retrospective case-control study using a random proportional sample of Armenian children with ASD to assess associations between various factors and ASD was conducted. The study was approved by the local ethical committee, and parental written consent was obtained. A total of 168 children with ASD and 329 controls were included in the analysis. Multivariable logistic regression analysis revealed that male gender, maternal weight gain, use of MgB6, self-reported stress during the pregnancy, pregnancy with complications, as well as use of labor-inducing drugs were associated with a significant increase in the odds of ASD, whereas Duphaston use during pregnancy, the longer interpregnancy interval and birth height were associated with decreased odds of ASD. These findings are pertinent as many identified factors may be preventable or modifiable, underscoring the importance of timely and appropriate public health strategies aimed at disease prevention in pregnant women to reduce ASD incidence.

Cortical dysmorphology and reduced cortico-collicular projections in an animal model of autism spectrum disorder

Autism spectrum disorder is a neurodevelopmental disability that includes sensory disturbances. Hearing is frequently affected and ranges from deafness to hypersensitivity. In utero exposure to the antiepileptic valproic acid is associated with increased risk of autism spectrum disorder in humans and timed valproic acid exposure is a biologically relevant and validated animal model of autism spectrum disorder. Valproic acid-exposed rats have fewer neurons in their auditory brainstem and thalamus, fewer calbindin-positive neurons, reduced ascending projections to the midbrain and thalamus, elevated thresholds, and delayed auditory brainstem responses. Additionally, in the auditory cortex, valproic acid exposure results in abnormal responses, decreased phase-locking, elevated thresholds, and abnormal tonotopic maps. We therefore hypothesized that in utero, valproic acid exposure would result in fewer neurons in auditory cortex, neuronal dysmorphology, fewer calbindin-positive neurons, and reduced connectivity. We approached this hypothesis using morphometric analyses, immunohistochemistry, and retrograde tract tracing. We found thinner cortical layers but no changes in the density of neurons, smaller pyramidal and non-pyramidal neurons in several regions, fewer neurons immunoreactive for calbindin-positive, and fewer cortical neurons projecting to the inferior colliculus. These results support the widespread impact of the auditory system in autism spectrum disorder and valproic acid-exposed animals and emphasize the utility of simple, noninvasive auditory screening for autism spectrum disorder.

Neurodevelopmental and Functional Outcomes Following In Utero Exposure to Antiseizure Medication: A Systematic Review

BACKGROUND AND OBJECTIVES

To undertake a systematic review of the available literature to examine the relationship between prenatal antiseizure medication (ASM) exposure and adverse postnatal neurodevelopmental outcomes, focusing on social, emotional, behavioral, and adaptive domains of human function, and the frequency of neurodevelopmental and psychiatric disorders in ASM-exposed offspring.

METHODS

Electronic searches of MEDLINE, PsychINFO, and EMBASE were conducted and limited to studies published between 1990 and 2023 in English. Studies were eligible if they prospectively or retrospectively reported neurodevelopmental outcomes of ASM-exposed offspring. The Newcastle-Ottawa scale was used to conduct methodologic quality assessments of included studies, and a narrative synthesis integrated the review findings.

RESULTS

Forty-three studies were included. Valproate has been consistently associated with a 2- to 4-fold increased risk of autism spectrum disorder (ASD), 2- to 5-fold increased risk of intellectual disability (ID), and poor adaptive functioning. Growing evidence indicates that topiramate is associated with a 2-fold increased risk of ASD and 3- to 4-fold increased risk of ID. The risks of adverse neurodevelopmental outcomes for valproate and topiramate seem to be dose dependent. Phenobarbital has been suggested to be associated with deleterious neurodevelopmental effects, but data are limited. Levetiracetam has recently been linked with an increased risk of attention deficit hyperactivity disorder and anxiety disorders in a single study. Carbamazepine has been associated with variable neurodevelopmental outcomes. Lamotrigine seems to be "safe" in terms of postnatal neurodevelopment. Data for oxcarbazepine, phenytoin, and clonazepam are limited but seem to have little-to-no risk of adverse outcomes. Evidence for the remaining ASMs, including gabapentin, pregabalin, lacosamide, zonisamide, clobazam, perampanel, ethosuximide, or brivaracetam, is lacking. Several methodologic limitations impeded data synthesis, including heterogeneity in outcome measures and small samples of monotherapy exposures.

DISCUSSION

The findings of this review support the conclusion that valproate and topiramate use during pregnancy is associated with a significantly increased risk of neurodevelopmental effects on the fetus. Apart from lamotrigine, which seems to be free of adverse neurodevelopmental effects, data for the other ASMs are mixed or inadequate to draw definite conclusions. Further research into the neurodevelopmental effects of prenatal exposure to ASMs, including most newer agents, is much needed.

Comparison of neurodevelopmental, educational and adult socioeconomic outcomes in offspring of women with and without epilepsy: A systematic review and meta-analysis

BACKGROUND

Adequate pre-pregnancy counselling and education planning are essential to improve outcomes for offspring of women with epilepsy (OWWE). The current systematic review and meta-analysis aimed to compare outcomes for OWWE and offspring of women without epilepsy (OWWoE).

METHODS

We conducted a systematic review and meta-analysis. We searched MEDLINE, EMBASE, CINAHL, PsycINFO (database inception-1st January 2023), OpenGrey, GoogleScholar, and hand-searched journals and reference lists of included studies to identify eligible studies. We placed no language restrictions and included observational studies concerning OWWE and OWWoE. We followed the PRIMSA checklist for abstracting data. The Newcastle-Ottawa Scale for risk of bias assessment was conducted independently by two authors with mediation by a third. We report pooled unadjusted odds ratios (OR) or mean differences (MD) with 95% confidence intervals (95CI) from random (I2>50%) or fixed (I2<50%) effects meta-analyses. Outcomes of interest included offspring autism, attention deficit/hyperactive disorder, intellectual disability, epilepsy, developmental disorder, intelligence, educational, and adulthood socioeconomic outcomes.

RESULTS

Of 10,928 articles identified, we included 21 in meta-analyses. OWWE had increased odds of autism (2 articles, 4,502,098 offspring) OR [95CI] 1·67 [1·54, 1·82], attention-deficit/hyperactivity disorder (3 articles, 957,581 offspring) 1·59 [1·44, 1·76], intellectual disability (2 articles, 4,501,786 children) 2·37 [2·13, 2·65], having special educational needs (3 articles, 1,308,919 children) 2·60 [1·07, 6·34]. OWWE had worse mean scores for full-scale intelligence (5 articles, 989 children) -6·05 [-10·31, -1·79]. No studies were identified that investigated adulthood socioeconomic outcomes.

CONCLUSIONS

Increased odds of poor outcomes are higher with greater anti-seizure medication burden including neurodevelopmental and educational outcomes. In fact, these two outcomes seem to be worse in OWWE compared to OWWoE, even if there was no ASM exposure during pregnancy, but further work is needed to take into account potential confounding factors.

Sex-dependent alterations of inflammatory factors, oxidative stress, and histopathology of the brain-gut axis in a VPA-induced autistic-like model of rats

INTRODUCTION

In this study, we aimed to investigate the inflammatory factors, oxidative stress, and histopathological consequences of the brain-gut axis in male and female rats prenatally exposed to VPA.

METHODS

Pregnant Wistar rats were randomly divided into two groups. The animals received saline, and valproic acid (VPA) (600 mg/kg, i.p.) on embryonic day 12.5 (E12.5). All offspring were weaned on postnatal day 21, and the experiments were done in male and female rats on day 60. The brain and intestine tissues were extracted to assess histopathology, inflammation, and oxidative stress.

RESULTS

An increase of interleukin-1β (IL-1β) and interleukin-6 (IL-6) and a decrease of interleukin-10 (IL-10) were observed in the two sexes and two tissues of the autistic rats. In the VPA-exposed animals, malondialdehyde (MDA) and protein carbonyl (PC) increased in the brain of both sexes and the intestines of only the males. The total antioxidant capacity (TAC), superoxide dismutase (SOD), and catalase (CAT) significantly decreased in both tissues of male and female autistic groups. Histopathological evaluation showed that the %apoptosis of the cortex in the autistic male and female groups was more than in controls whereas this parameter in the CA1 and CA3 was significant only in the male rats. In the intestine, histopathologic changes were seen only in the male autistic animals.

CONCLUSION

The inflammatory and antioxidant factors were in line in the brain-gut axis in male and female rats prenatally exposed to VPA. Histopathological consequences were more significant in the VPA-exposed male animals.

Risk of Autism after Prenatal Topiramate, Valproate, or Lamotrigine Exposure

BACKGROUND

Maternal use of valproate during pregnancy has been associated with an increased risk of neurodevelopmental disorders in children. Although most studies of other antiseizure medications have not shown increased risks of these disorders, there are limited and conflicting data regarding the risk of autism spectrum disorder associated with maternal topiramate use.

METHODS

We identified a population-based cohort of pregnant women and their children within two health care utilization databases in the United States, with data from 2000 through 2020. Exposure to specific antiseizure medications was defined on the basis of prescription fills from gestational week 19 until delivery. Children who had been exposed to topiramate during the second half of pregnancy were compared with those unexposed to any antiseizure medication during pregnancy with respect to the risk of autism spectrum disorder. Valproate was used as a positive control, and lamotrigine was used as a negative control.

RESULTS

The estimated cumulative incidence of autism spectrum disorder at 8 years of age was 1.9% for the full population of children who had not been exposed to antiseizure medication (4,199,796 children). With restriction to children born to mothers with epilepsy, the incidence was 4.2% with no exposure to antiseizure medication (8815 children), 6.2% with exposure to topiramate (1030 children), 10.5% with exposure to valproate (800 children), and 4.1% with exposure to lamotrigine (4205 children). Propensity score-adjusted hazard ratios in a comparison with no exposure to antiseizure medication were 0.96 (95% confidence interval [CI], 0.56 to 1.65) for exposure to topiramate, 2.67 (95% CI, 1.69 to 4.20) for exposure to valproate, and 1.00 (95% CI, 0.69 to 1.46) for exposure to lamotrigine.

CONCLUSIONS

The incidence of autism spectrum disorder was higher among children prenatally exposed to the studied antiseizure medications than in the general population. However, after adjustment for indication and other confounders, the association was substantially attenuated for topiramate and lamotrigine, whereas an increased risk remained for valproate. (Funded by the National Institute of Mental Health.).

Autism spectrum disorders and the gastrointestinal tract: insights into mechanisms and clinical relevance

Autism spectrum disorders (ASDs) are recognized as central neurodevelopmental disorders diagnosed by impairments in social interactions, communication and repetitive behaviours. The recognition of ASD as a central nervous system (CNS)-mediated neurobehavioural disorder has led most of the research in ASD to be focused on the CNS. However, gastrointestinal function is also likely to be affected owing to the neural mechanistic nature of ASD and the nervous system in the gastrointestinal tract (enteric nervous system). Thus, it is unsurprising that gastrointestinal disorders, particularly constipation, diarrhoea and abdominal pain, are highly comorbid in individuals with ASD. Gastrointestinal problems have also been repeatedly associated with increased severity of the core symptoms diagnostic of ASD and other centrally mediated comorbid conditions, including psychiatric issues, irritability, rigid-compulsive behaviours and aggression. Despite the high prevalence of gastrointestinal dysfunction in ASD and its associated behavioural comorbidities, the specific links between these two conditions have not been clearly delineated, and current data linking ASD to gastrointestinal dysfunction have not been extensively reviewed. This Review outlines the established and emerging clinical and preclinical evidence that emphasizes the gut as a novel mechanistic and potential therapeutic target for individuals with ASD.

Neurodevelopmental outcomes after prenatal exposure to lamotrigine monotherapy in women with epilepsy: a systematic review and meta-analysis

BACKGROUND

Lamotrigine has become one of the most commonly prescribed antiseizure medications (ASM) in epileptic women during pregnancy and therefore requires regular updates regarding its safety. The aim of this study was to estimate the association between in utero exposure to lamotrigine monotherapy and the occurrence of neurodevelopmental outcomes.

METHODS

All comparative studies assessing the occurrence of neurodevelopmental outcomes after epilepsy-indicated lamotrigine monotherapy exposure during pregnancy were searched. First, references were identified through a snowballing approach, then, through electronic databases (Medline and Embase) from 2015 to June 2022. One investigator evaluated study eligibility and extracted data and a second independent investigator reviewed the meta-analysis (MA). A systematic review and random-effects model approach were performed using a collaborative WEB-based meta-analysis platform (metaPreg.org) with a registered protocol (osf.io/u4gva).

RESULTS

Overall, 18 studies were included. For outcomes reported by at least 4 studies, the pooled odds ratios and 95% confidence interval obtained with the number of exposed (N1) and unexposed children (N0) included were: neurodevelopmental disorders as a whole 0.84 [0.66;1.06] (N1 = 5,271; N0 = 22,230); language disorders or delay 1.16 [0.67;2.00] (N1 = 313; N0 = 506); diagnosis or risk of ASD 0.97 [0.61;1.53] (N1 = at least 5,262; N0 = 33,313); diagnosis or risk of ADHD 1.14 [0.75;1.72] (N1 = at least 113; N0 = 11,530) and psychomotor developmental disorders or delay 2.68 [1.29-5.56] (N1 = 163; N0 = 220). The MA of cognitive outcomes included less than 4 studies and retrieved a significant association for infants exposed to lamotrigine younger than 3 years old but not in the older age groups.

CONCLUSION

Prenatal exposure to lamotrigine monotherapy is not found to be statistically associated with neurodevelopmental disorders as a whole, language disorders or delay, diagnosis or risk of ASD and diagnosis or risk of ADHD. However, the MA found an increased risk of psychomotor developmental disorders or delay and cognitive developmental delay in less than 3 years old children. Nevertheless, these findings were based exclusively on observational studies presenting biases and on a limited number of included children. More studies should assess neurodevelopmental outcomes in children prenatally exposed to lamotrigine.

Transmission of behavioral and cognitive impairments across generations in rats subjected to prenatal valproic acid exposure

BACKGROUND

Autism spectrum disorder (ASD) represents an inheritable neurodevelopmental condition characterized by social communication deficits and repetitive behaviors. Numerous studies have underscored the significant roles played by genetic and environmental factors in the etiology of ASD, and these factors are known to perpetuate behavioral impairments across generations.

OBJECTIVES

The primary objective of this study was to assess the behavioral and cognitive attributes in the second filial (F2) generation of male and female rats, with a particular focus on those whose parents had been exposed to valproic acid (VPA) during embryonic development.

METHODS

In this study, a cohort of 32 male and 32 female rats from the second filial (F2) generation, referred to as Mother.ASD, Father.ASD, or Both.ASD, was examined. These designations indicate whether the mother, father, or both parents had experienced embryonic exposure to valproic acid (600 mg/kg, i.p.). During adolescence, the F2 pups underwent behavioral and cognitive assessments, including open field testing, marble burying, social interaction evaluations, and Morris water maze tasks.

RESULTS

Our data revealed that while both the Mother.ASD and Father.ASD groups, regardless of sex, exhibited elevated anxiety-like behavior in the open field test. Only the Mother.ASD group displayed repetitive behaviors and deficits in social memory. Additionally, spatial memory impairments were observed in both sexes. These findings highlight the transmission of autistic-like behaviors in the offspring of Mother.ASD rats from both sexes. Nevertheless, future research endeavors should be more targeted in identifying the specific genes responsible for this transmission.

CONCLUSION

In summary, our findings underscore the transmission of autistic-like behaviors, including anxiety-like behavior, repetitive actions, impairments in social interactions, and deficits in memory, to the offspring of the Mother.ASD group, irrespective of their sex.

Postpartum Psychosis: A Proposed Treatment Algorithm

Background

Postpartum psychosis (PPP) is a psychiatric emergency that generally warrants acute inpatient care. PPP is marked by the sudden onset of affective and psychotic symptoms with a rapid deterioration in mental state. Evidence suggests that PPP is a discrete disorder on the bipolar disorder spectrum with a distinct treatment profile and prognosis.

Methods

We conducted a PubMed database search for various terms involving PPP and its treatment and included peer-reviewed articles published in English.

Objective

To provide a treatment algorithm for the management of PPP based on available evidence.

Results

Pharmacological therapy is the mainstay of PPP management in the acute phase. Evidence points to a combination of antipsychotics and lithium in the acute treatment of PPP. Electroconvulsive therapy can offer a rapid treatment response where required. Lithium appears to have the best evidence for relapse prevention and prophylaxis in PPP. Psychoeducation is essential and psychosocial interventions used in bipolar disorder may be effective in PPP.

Conclusion

Early detection and prompt treatment with antipsychotics and lithium, followed by maintenance treatment with lithium, is associated with a favourable prognosis in PPP.Reprinted from J Psychopharmacol 2023; 37:960-970, with permission from Sage Journals. Copyright © 2023.

Three Decades of Valproate: A Current Model for Studying Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with increased prevalence and incidence in recent decades. Its etiology remains largely unclear, but it seems to involve a strong genetic component and environmental factors that, in turn, induce epigenetic changes during embryonic and postnatal brain development. In recent decades, clinical studies have shown that inutero exposure to valproic acid (VPA), a commonly prescribed antiepileptic drug, is an environmental factor associated with an increased risk of ASD. Subsequently, prenatal VPA exposure in rodents has been established as a reliable translational model to study the pathophysiology of ASD, which has helped demonstrate neurobiological changes in rodents, non-human primates, and brain organoids from human pluripotent stem cells. This evidence supports the notion that prenatal VPA exposure is a valid and current model to replicate an idiopathic ASD-like disorder in experimental animals. This review summarizes and describes the current features reported with this animal model of autism and the main neurobiological findings and correlates that help elucidate the pathophysiology of ASD. Finally, we discuss the general framework of the VPA model in comparison to other environmental and genetic ASD models.

Environmental Risk Factors in Autism Spectrum Disorder: A Narrative Review

Existing evidence indicates that environmental factors might contribute up to 50% of the variance in autism spectrum disorder (ASD) risk. This structured narrative review offers a comprehensive synthesis of current knowledge on environmental risk factors in ASD, including evaluation of conflicting evidence, exploration of underlying mechanisms, and suggestions for future research directions. Analysis of diverse epidemiological investigations indicates that certain environmental factors, including advanced parental age, preterm birth, delivery complications, and exposure to toxic metals, drugs, air pollutants, and endocrine-disrupting chemicals, are linked to an increased ASD risk through various mechanisms such as oxidative stress, inflammation, hypoxia, and its consequences, changes in neurotransmitters, disruption of signaling pathways and some others. On the other hand, pregnancy-related factors such as maternal diabetes, maternal obesity, and caesarian section show a weaker association with ASD risk. At the same time, other environmental factors, such as vaccination, maternal smoking, or alcohol consumption, are not linked to the risk of ASD. Regarding nutritional elements data are inconclusive. These findings highlight the significance of environmental factors in ASD etiology and emphasize that more focused research is needed to target the risk factors of ASD. Environmental interventions targeting modifiable risk factors might offer promising avenues for ASD prevention and treatment.

Valproic Acid in Pregnancy Revisited: Neurobehavioral, Biochemical and Molecular Changes Affecting the Embryo and Fetus in Humans and in Animals: A Narrative Review

Valproic acid (VPA) is a very effective anticonvulsant and mood stabilizer with relatively few side effects. Being an epigenetic modulator, it undergoes clinical trials for the treatment of advanced prostatic and breast cancer. However, in pregnancy, it seems to be the most teratogenic antiepileptic drug. Among the proven effects are congenital malformations in about 10%. The more common congenital malformations are neural tube defects, cardiac anomalies, urogenital malformations including hypospadias, skeletal malformations and orofacial clefts. These effects are dose related; daily doses below 600 mg have a limited teratogenic potential. VPA, when added to other anti-seizure medications, increases the malformations rate. It induces malformations even when taken for indications other than epilepsy, adding to the data that epilepsy is not responsible for the teratogenic effects. VPA increases the rate of neurodevelopmental problems causing reduced cognitive abilities and language impairment. It also increases the prevalence of specific neurodevelopmental syndromes like autism (ASD) and Attention Deficit Hyperactivity Disorder (ADHD). High doses of folic acid administered prior to and during pregnancy might alleviate some of the teratogenic effect of VPA and other AEDs. Several teratogenic mechanisms are proposed for VPA, but the most important mechanisms seem to be its effects on the metabolism of folate, SAMe and histones, thus affecting DNA methylation. VPA crosses the human placenta and was found at higher concentrations in fetal blood. Its concentrations in milk are low, therefore nursing is permitted. Animal studies generally recapitulate human data.

The Notch1/Hes1 signaling pathway affects autophagy by adjusting DNA methyltransferases expression in a valproic acid-induced autism spectrum disorder model

As a pervasive neurodevelopmental disease, autism spectrum disorder (ASD) is caused by both hereditary and environmental elements. Research has demonstrated the functions of the Notch pathway and DNA methylation in the etiology of ASD. DNA methyltransferases DNMT3 and DNMT1 are responsible for methylation establishment and maintenance, respectively. In this study, we aimed to explore the association of DNA methyltransferases with the Notch pathway in ASD. Our results showed Notch1 and Hes1 were upregulated, while DNMT3A and DNMT3B were downregulated at the protein level in the prefrontal cortex (PFC), hippocampus (HC) and cerebellum (CB) of VPA-induced ASD rats compared with Control (Con) group. However, the protein levels of DNMT3A and DNMT3B were augmented after treatment with 3,5-difluorophenacetyl-L-alanyl-S-phenylglycine-2-butyl ester (DAPT), suggesting that abnormal Notch pathway activation may affect the expression of DNMT3A and DNMT3B. Besides, our previous findings revealed that the Notch pathway may participate in development of ASD by influencing autophagy. Therefore, we hypothesized the Notch pathway adjusts autophagy and contributes to ASD by affecting DNA methyltransferases. Our current results showed that after receiving the DNA methyltransferase inhibitor 5-Aza-2'-deoxycytidine (5-Aza-2'dc), the VPA + DAPT+5-Aza-2'dc (V + D + Aza) group exhibited reduced social interaction ability and increased stereotyped behaviors, and decreased expression of DNMT3A, DNMT3B and autophagy-related proteins, but did not show changes in Notch1 and Hes1 protein levels. Our results indicated that the Notch1/Hes1 pathway may adjust DNMT3A and DNMT3B expression and subsequently affect autophagy in the occurrence of ASD, providing new insight into the pathogenesis of ASD.

Neurodevelopmental outcomes in children and adults with Fetal Valproate Spectrum Disorder: A contribution from the ConcePTION project

AIM

To describe the neurodevelopmental phenotype of older children and adults with a diagnosis of Fetal Valproate Spectrum Disorder (FVSD).

METHODS

In this cross-sectional study, 90 caregivers were recruited and completed a series of questionnaires regarding the neurodevelopmental outcomes of 146 individuals aged 7-37 years (M = 18.1), including individuals with a formal diagnosis of FVSD (n = 99), individuals exposed to Valproate but without an FVSD diagnosis (n = 24), and individuals not exposed to Valproate (N = 23). The mean dose of valproate exposure for individuals with an FVSD diagnosis was 1470 mg/day.

RESULTS

Individuals with a diagnosis of FVSD showed significantly higher levels of moderate (43.4%) and severe (14.4%) cognitive impairment than other groups (p = 0.003), high levels of required formal educational support (77.6%), and poorer academic competence than individuals not exposed to Valproate (p = 0.001). Overall psychosocial problems (p = 0.02), internalising problems (p = 0.05) and attention problems (p = 0.001), but not externalising problems, were elevated in individuals with a diagnosis of FVSD. Rates of neurodevelopmental disorders, particularly autistic spectrum disorders (62.9%) and sensory problems (80.6%) are particularly central to the FVSD phenotype. There was no evidence of a statistical dose-dependent effect, possibly due to the high mean dose of exposure having a uniformly negative impact across the sample. Individuals with FVSD had required a significant number of health and child development services.

INTERPRETATION

Children and young adults with a diagnosis of FVSD are at an increased risk of a range of altered neurodevelopmental outcomes, highlighting the need for a multidisciplinary approach to clinical management across the lifespan.

Postpartum psychosis: A proposed treatment algorithm

BACKGROUND

Postpartum psychosis (PPP) is a psychiatric emergency that generally warrants acute inpatient care. PPP is marked by the sudden onset of affective and psychotic symptoms with a rapid deterioration in mental state. Evidence suggests that PPP is a discrete disorder on the bipolar disorder spectrum with a distinct treatment profile and prognosis.

METHODS

We conducted a PubMed database search for various terms involving PPP and its treatment and included peer-reviewed articles published in English.

OBJECTIVE

To provide a treatment algorithm for the management of PPP based on available evidence.

RESULTS

Pharmacological therapy is the mainstay of PPP management in the acute phase. Evidence points to a combination of antipsychotics and lithium in the acute treatment of PPP. Electroconvulsive therapy can offer a rapid treatment response where required. Lithium appears to have the best evidence for relapse prevention and prophylaxis in PPP. Psychoeducation is essential and psychosocial interventions used in bipolar disorder may be effective in PPP.

CONCLUSION

Early detection and prompt treatment with antipsychotics and lithium, followed by maintenance treatment with lithium, is associated with a favourable prognosis in PPP.

Neurodevelopment of babies born to mothers with epilepsy: A prospective observational cohort study

OBJECTIVE

Despite widespread monotherapy use of lamotrigine or levetiracetam during pregnancy, prospectively collected, blinded child development data are still limited. The NaME (Neurodevelopment of Babies Born to Mothers With Epilepsy) Study prospectively recruited a new cohort of women with epilepsy and their offspring for longitudinal follow-up.

METHODS

Pregnant women of <21 weeks gestation (n = 401) were recruited from 21 hospitals in the UK. Data collection occurred during pregnancy (recruitment, trimester 3) and at 12 and 24 months of age. The primary outcome was blinded assessment of infant cognitive, language, and motor development on the Bayley Scales of Infant and Toddler Development (3rd edition) at 24 months of age with supplementary parent reporting on the Vinelands Adaptive Behavior Scales (2nd edition).

RESULTS

There were 394 live births, with 277 children (70%) completing the Bayley assessment at 24 months. There was no evidence of an association of prenatal exposure to monotherapy lamotrigine (-.74, SE = 2.9, 95% confidence interval [CI] = -6.5 to 5.0, p = .80) or levetiracetam (-1.57, SE = 3.1, 95% CI = -4.6 to 7.7, p = .62) with poorer infant cognition, following adjustment for other maternal and child factors in comparison to nonexposed children. Similar results were observed for language and motor scores. There was no evidence of an association between increasing doses of either lamotrigine or levetiracetam. Nor was there evidence that higher dose folic acid supplementation (≥5 mg/day) or convulsive seizure exposure was associated with child development scores. Continued infant exposure to antiseizure medications through breast milk was not associated with poorer outcomes, but the number of women breastfeeding beyond 3 months was low.

SIGNIFICANCE

These data are reassuring for infant development following in utero exposure to monotherapy lamotrigine or levetiracetam, but child development is dynamic, and future follow-up is required to rule out later emerging effects.

Abnormal auditory brainstem responses in an animal model of autism spectrum disorder

Auditory dysfunction is a common feature of autism spectrum disorder (ASD) and ranges from deafness to hypersensitivity. The auditory brainstem response (ABR) permits study of the amplitude and latency of synchronized electrical activity along the ascending auditory pathway in response to clicks and pure tone stimuli. Indeed, numerous studies have shown that subjects with ASD have ABR abnormalities. In utero exposure to the antiepileptic drug valproic acid (VPA) is associated with human cases of ASD and is used as an animal model of ASD. Previous studies have shown that VPA-exposed animals have significantly fewer neurons in the auditory brainstem and thalamus, reduced ascending projections to the auditory midbrain and thalamus and increased neuronal activation in response to pure tone stimuli. Accordingly, we hypothesized that VPA-exposed animals would have abnormal ABRs throughout their lifespans. We approached this hypothesis in two cohorts. First, we examined ABRs from both ears on postnatal day 22 (P22). Then, we examined monaural ABRs in animals at P28, 60, 120, 180, 240, 300 and 360. Our results suggest that at P22, VPA-exposed animals have elevated thresholds and increased peak latencies. However, by P60 these differences largely normalize with differences appearing only near hearing threshold. Additionally, our analysis revealed that maturation of ABR waves occurred at different trajectories in control and VPA-exposed animals. These results, together with our previous work, suggest that VPA exposure not only impacts total neuron number and connectivity, but also auditory evoked responses. Finally, our longitudinal analysis suggests that delayed maturation of auditory brainstem circuits may impact ABRs throughout the lifespan of the animal.

Dysregulation of the chromatin environment leads to differential alternative splicing as a mechanism of disease in a human model of autism spectrum disorder

Autism spectrum disorder (ASD) affects 1 in 44 children. Chromatin regulatory proteins are overrepresented among genes that contain high risk variants in ASD. Disruption of the chromatin environment leads to widespread dysregulation of gene expression, which is traditionally thought of as a mechanism of disease pathogenesis associated with ASD. Alternatively, alterations in chromatin dynamics could also lead to dysregulation of alternative splicing, which is understudied as a mechanism of ASD pathogenesis. The anticonvulsant valproic acid (VPA) is a well-known environmental risk factor for ASD that acts as a class I histone deacetylase inhibitor. However, the precise molecular mechanisms underlying defects in human neuronal development associated with exposure to VPA are understudied. To dissect how VPA exposure and subsequent chromatin hyperacetylation influence molecular signatures involved in ASD pathogenesis, we conducted RNA sequencing (RNA-seq) in human cortical neurons that were treated with VPA. We observed that differentially expressed genes (DEGs) were enriched for mRNA splicing, mRNA processing, histone modification and metabolism related gene sets. Furthermore, we observed widespread increases in the number and the type of alternative splicing events. Analysis of differential transcript usage (DTU) showed that exposure to VPA induces extensive alterations in transcript isoform usage across neurodevelopmentally important genes. Finally, we find that DEGs and genes that display DTU overlap with known ASD-risk genes. Altogether, these findings suggest that, in addition to differential gene expression, changes in alternative splicing correlated with alterations in the chromatin environment could act as an additional mechanism of disease in ASD.

In utero Exposure to Valproic Acid throughout Pregnancy Causes Phenotypes of Autism in Offspring Mice

Valproic acid (VPA) is an antiepileptic drug that inhibits the epileptic activity of neurons mainly by inhibiting sodium channels and GABA transaminase. VPA is also known to inhibit histone deacetylases, which epigenetically modify the cell proliferation/differentiation characteristics of stem/progenitor cells within developing tissues. Recent clinical studies in humans have indicated that VPA exposure in utero increases the risk of autistic features and intellectual disabilities in offspring; we have previously reported that low-dose VPA exposure in utero throughout pregnancy increases the production of projection neurons from neuronal stem/progenitor cells that are distributed in the superficial neocortical layers of the fetal brain. In the present study, we found that in utero VPA-exposed mice exhibited abnormal social interaction, changes in cognitive function, hypersensitivity to pain/heat, and impaired locomotor activity, all of which are characteristic symptoms of autism spectrum disorder in humans. Taken together, our findings indicate that VPA exposure in utero throughout pregnancy alters higher brain function and predisposes individuals to phenotypes that resemble autism and intellectual disability. Furthermore, these symptoms are likely to be due to neocortical dysgenesis that was caused by an increased number of projection neurons in specific layers of the neocortex.

Antiseizure Medications in Pregnancy

Epilepsy affects up to 15 million of people assigned female at birth of childbearing age globally. Up to 65% of these people with epilepsy and gestational capacity have an unplanned pregnancy. Seizure control during pregnancy is important for both the childbearer's and fetus' safety. There are multiple antiseizure medications (ASMs) that can be used to control epilepsy; however, each medication has its own teratogenic risk profile, which must be considered. The majority of these ASMs will require frequent plasma concentration monitoring during pregnancy with corresponding dosage adjustments. Dosages can be reduced back to prepregnancy levels within 3 weeks postpartum. Breastfeeding on ASMs is recommended.

Adaptive behaviour in children exposed to topiramate in the womb: An observational cohort study

OBJECTIVE

Many women with epilepsy need to continue anti-seizure medications (ASMs) throughout pregnancy. The current study investigated adaptive behaviour outcomes in children exposed to topiramate in the womb.

METHOD

An observational, cross-sectional study was designed, recruiting mother-child-pairs from the UK Epilepsy and Pregnancy Register (UKEPR). Health, developmental histories and Vineland Adaptive Behaviour Scale-Third Edition (VABS-III) assessments were administered via telephone by a blinded researcher, supplemented with prospectively collected pregnancy and medication information. Topiramate monotherapy exposed children were compared to VABS-III normative data as recruitment was disrupted by the COVID-19 pandemic.

RESULTS

Thirty-four women with epilepsy from 135 (25%) initially agreed to participate in the study, of whom 26 women completed telephone interviews about their children (n = 28). Children ranged from 2.5 to 17 years of age at the time of assessment. Six topiramate-exposed children were born small for gestational age, and there were significant associations between birthweight, dose and VABS-III scores. Significantly lower scores were observed in topiramate-exposed children (n = 21) with a significant dose-response relationship established after adjustment for parental educational level. Daily mean dosage was 280.21 mg, with high dosages of topiramate associated with a 12-point reduction in VABS-III scores. Additionally, four topiramate-exposed children (19.05%) had diagnoses of Autism Spectrum Disorder, which was significantly higher than UK prevalence rates (1.1%).

CONCLUSIONS

The findings of poorer adaptive behaviour, higher incidence of ASD and associations with birth weight are of concern and require further validation and replication using larger prospectively-recruited samples and comparator cohorts. Implications for research and clinical practice are discussed.

Cochrane Epilepsy Group, Maguire MJ, Fairclough S, Nevitt SJ. Antiepileptic drugs for treating seizures in people with brain tumours

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To compare the efficacy and tolerability of antiepileptic drugs (AEDs) taken as monotherapy or add‐on therapy for seizures in people with brain tumours.

Valproic acid affects neurogenesis during early optic tectum development in zebrafish

The mammalian superior colliculus and its non-mammalian homolog, the optic tectum (OT), are midbrain structures that integrate multimodal sensory inputs and guide non-voluntary movements in response to prevalent stimuli. Recent studies have implicated this structure as a possible site affected in autism spectrum disorder (ASD). Interestingly, fetal exposure to valproic acid (VPA) has also been associated with an increased risk of ASD in humans and animal models. Therefore, we took the approach of determining the effects of VPA treatment on zebrafish OT development as a first step in identifying the mechanisms that allow its formation. We describe normal OT development during the first 5 days of development and show that in VPA-treated embryos, neuronal specification and neuropil formation was delayed. VPA treatment was most detrimental during the first 3 days of development and did not appear to be linked to oxidative stress. In conclusion, our work provides a foundation for research into mechanisms driving OT development, as well as the relationship between the OT, VPA, and ASD. This article has an associated First Person interview with one of the co-first authors of the paper.

Global metabolic profiles in a non-human primate model of maternal immune activation: implications for neurodevelopmental disorders

Epidemiological evidence implicates severe maternal infections as risk factors for neurodevelopmental disorders, such as ASD and schizophrenia. Accordingly, animal models mimicking infection during pregnancy, including the maternal immune activation (MIA) model, result in offspring with neurobiological, behavioral, and metabolic phenotypes relevant to human neurodevelopmental disorders. Most of these studies have been performed in rodents. We sought to better understand the molecular signatures characterizing the MIA model in an organism more closely related to humans, rhesus monkeys (Macaca mulatta), by evaluating changes in global metabolic profiles in MIA-exposed offspring. Herein, we present the global metabolome in six peripheral tissues (plasma, cerebrospinal fluid, three regions of intestinal mucosa scrapings, and feces) from 13 MIA and 10 control offspring that were confirmed to display atypical neurodevelopment, elevated immune profiles, and neuropathology. Differences in lipid, amino acid, and nucleotide metabolism discriminated these MIA and control samples, with correlations of specific metabolites to behavior scores as well as to cytokine levels in plasma, intestinal, and brain tissues. We also observed modest changes in fecal and intestinal microbial profiles, and identify differential metabolomic profiles within males and females. These findings support a connection between maternal immune activation and the metabolism, microbiota, and behavioral traits of offspring, and may further the translational applications of the MIA model and the advancement of biomarkers for neurodevelopmental disorders such as ASD or schizophrenia.

Modulation of human endogenous retroviruses and cytokines expression in peripheral blood mononuclear cells from autistic children and their parents

BACKGROUND

Putative pathogenic effects mediated by human endogenous retroviruses (HERVs) in neurological and psychiatric disorders in humans have been extensively described. HERVs may alter the development of the brain by means of several mechanisms, including modulation of gene expression, alteration of DNA stability, and activation of immune system. We recently demonstrated that autistic children and their mothers share high expression levels of some HERVs and cytokines in peripheral blood mononuclear cells (PBMCs) ex vivo, suggesting a close mother-child association in Autism Spectrum Disorder (ASD).

RESULTS

In the present study, PBMCs from autistic children and their parents were exposed to stimulating factors (Interleukin-2/Phytohaemagglutinin) or drugs, as Valproic acid and Efavirenz. The results show that HERVs and cytokines expression can be modulated in vitro by different stimuli in PBMCs from autistic children and their mothers, while no significant changes were found in PBMCs ASD fathers or in controls individuals. In particular, in vitro exposure to interleukin-2/Phytohaemagglutinin or valproic acid induces the expression of several HERVs and cytokines while Efavirenz inhibits them.

CONCLUSION

Herein we show that autistic children and their mothers share an intrinsic responsiveness to in vitro microenvironmental changes in expressing HERVs and pro-inflammatory cytokines. Remarkably, the antiretroviral drug Efavirenz restores the expression of specific HERV families to values similar to those of the controls, also reducing the expression of proinflammatory cytokines but keeping the regulatory ones high. Our findings open new perspectives to study the role of HERVs in the biological mechanisms underlying Autism.