The Cerebellum and Neurodevelopmental Disorders

Case report and systematic review of cerebellar vermis alterations in psychosis

INTRODUCTION

Cerebellar alterations, including both volumetric changes in the cerebellar vermis and dysfunctions of the corticocerebellar connections, have been documented in psychotic disorders. Starting from the clinical observation of a bipolar patient with cerebellar hypoplasia, the purpose of this review is to summarize the data in the literature about the association between hypoplasia of the cerebellar vermis and psychotic disorders [schizophrenia (SCZ) and bipolar disorder (BD)].

METHODS

A bibliographic search on PubMed has been conducted, and 18 articles were finally included in the review: five used patients with BD, 12 patients with SCZ and one subject at psychotic risk.

RESULTS

For SCZ patients and subjects at psychotic risk, the results of most of the reviewed studies seem to suggest a gray matter volume reduction coupled with an increase in white matter volumes in the cerebellar vermis, compared to healthy controls. Instead, the results of the studies on BD patients are more heterogeneous with evidence showing a reduction, no difference or even an increase in cerebellar vermis volume compared to healthy controls.

CONCLUSIONS

From the results of the reviewed studies, a possible correlation emerged between cerebellar vermis hypoplasia and psychotic disorders, especially SCZ, ultimately supporting the hypothesis of psychotic disorders as neurodevelopmental disorders.

Heritability of cerebellar subregion volumes in adolescent and young adult twins

Twin studies have found gross cerebellar volume to be highly heritable. However, whether fine-grained regional volumes within the cerebellum are similarly heritable is still being determined. Anatomical MRI scans from two independent datasets (QTIM: Queensland Twin IMaging, N = 798, mean age 22.1 years; QTAB: Queensland Twin Adolescent Brain, N = 396, mean age 11.3 years) were combined with an optimised and automated cerebellum parcellation algorithm to segment and measure 28 cerebellar regions. We show that the heritability of regional volumetric measures varies widely across the cerebellum (h 2 $$ {h}^2 $$ 47%-91%). Additionally, the good to excellent test-retest reliability for a subsample of QTIM participants suggests that non-genetic variance in cerebellar volumes is due primarily to unique environmental influences rather than measurement error. We also show a consistent pattern of strong associations between the volumes of homologous left and right hemisphere regions. Associations were predominantly driven by genetic effects shared between lobules, with only sparse contributions from environmental effects. These findings are consistent with similar studies of the cerebrum and provide a first approximation of the upper bound of heritability detectable by genome-wide association studies.

Exploring brain plasticity in developmental dyslexia through implicit sequence learning

Developmental dyslexia (DD) is defined as difficulties in learning to read even with normal intelligence and adequate educational guidance. Deficits in implicit sequence learning (ISL) abilities have been reported in children with DD. We investigated brain plasticity in a group of 17 children with DD, compared with 18 typically developing (TD) children, after two sessions of training on a serial reaction time (SRT) task with a 24-h interval. Our outcome measures for the task were: a sequence-specific implicit learning measure (ISL), entailing implicit recognition and learning of sequential associations; and a general visuomotor skill learning measure (GSL). Gray matter volume (GMV) increased, and white matter volume (WMV) decreased from day 1 to day 2 in cerebellar areas regardless of group. A moderating effect of group was found on the correlation between WMV underlying the left precentral gyrus at day 2 and the change in ISL performance, suggesting the use of different underlying learning mechanisms in DD and TD children during the ISL task. Moreover, DD had larger WMV in the posterior thalamic radiation compared with TD, supporting previous reports of atypical development of this structure in DD. Further studies with larger sample sizes are warranted to validate these results.

Structural deviations of the posterior fossa and the cerebellum and their cognitive links in a neurodevelopmental deletion syndrome

High-impact genetic variants associated with neurodevelopmental disorders provide biologically-defined entry points for mechanistic investigation. The 3q29 deletion (3q29Del) is one such variant, conferring a 40-100-fold increased risk for schizophrenia, as well as high risk for autism and intellectual disability. However, the mechanisms leading to neurodevelopmental disability remain largely unknown. Here, we report the first in vivo quantitative neuroimaging study in individuals with 3q29Del (N = 24) and neurotypical controls (N = 1608) using structural MRI. Given prior radiology reports of posterior fossa abnormalities in 3q29Del, we focused our investigation on the cerebellum and its tissue-types and lobules. Additionally, we compared the prevalence of cystic/cyst-like malformations of the posterior fossa between 3q29Del and controls and examined the association between neuroanatomical findings and quantitative traits to probe gene-brain-behavior relationships. 3q29Del participants had smaller cerebellar cortex volumes than controls, before and after correction for intracranial volume (ICV). An anterior-posterior gradient emerged in finer grained lobule-based and voxel-wise analyses. 3q29Del participants also had larger cerebellar white matter volumes than controls following ICV-correction and displayed elevated rates of posterior fossa arachnoid cysts and mega cisterna magna findings independent of cerebellar volume. Cerebellar white matter and subregional gray matter volumes were associated with visual-perception and visual-motor integration skills as well as IQ, while cystic/cyst-like malformations yielded no behavioral link. In summary, we find that abnormal development of cerebellar structures may represent neuroimaging-based biomarkers of cognitive and sensorimotor function in 3q29Del, adding to the growing evidence identifying cerebellar pathology as an intersection point between syndromic and idiopathic forms of neurodevelopmental disabilities.

Chromatin accessibility during human first-trimester neurodevelopment

The human brain develops through a tightly organized cascade of patterning events, induced by transcription factor expression and changes in chromatin accessibility. Although gene expression across the developing brain has been described at single-cell resolution1, similar atlases of chromatin accessibility have been primarily focused on the forebrain2-4. Here we describe chromatin accessibility and paired gene expression across the entire developing human brain during the first trimester (6-13 weeks after conception). We defined 135 clusters and used multiomic measurements to link candidate cis-regulatory elements to gene expression. The number of accessible regions increased both with age and along neuronal differentiation. Using a convolutional neural network, we identified putative functional transcription factor-binding sites in enhancers characterizing neuronal subtypes. We applied this model to cis-regulatory elements linked to ESRRB to elucidate its activation mechanism in the Purkinje cell lineage. Finally, by linking disease-associated single nucleotide polymorphisms to cis-regulatory elements, we validated putative pathogenic mechanisms in several diseases and identified midbrain-derived GABAergic neurons as being the most vulnerable to major depressive disorder-related mutations. Our findings provide a more detailed view of key gene regulatory mechanisms underlying the emergence of brain cell types during the first trimester and a comprehensive reference for future studies related to human neurodevelopment.

Activation and functional connectivity of cerebellum during reading and during arithmetic in children with combined reading and math disabilities

Background

Reading and math constitute important academic skills, and as such, reading disability (RD or developmental dyslexia) and math disability (MD or developmental dyscalculia) can have negative consequences for children's educational progress. Although RD and MD are different learning disabilities, they frequently co-occur. Separate theories have implicated the cerebellum and its cortical connections in RD and in MD, suggesting that children with combined reading and math disability (RD + MD) may have altered cerebellar function and disrupted functional connectivity between the cerebellum and cortex during reading and during arithmetic processing.

Methods

Here we compared Control and RD + MD groups during a reading task as well as during an arithmetic task on (i) activation of the cerebellum, (ii) background functional connectivity, and (iii) task-dependent functional connectivity between the cerebellum and the cortex.

Results

The two groups (Control, RD + MD) did not differ for either task (reading, arithmetic) on any of the three measures (activation, background functional connectivity, task-dependent functional connectivity).

Conclusion

These results do not support theories that children's deficits in reading and math originate in the cerebellum.

MRI morphometry of the anterior and posterior cerebellar vermis and its relationship to sensorimotor and cognitive functions in children

INTRODUCTION

The human cerebellum emerges as a posterior brain structure integrating neural networks for sensorimotor, cognitive, and emotional processing across the lifespan. Developmental studies of the cerebellar anatomy and function are scant. We examine age-dependent MRI morphometry of the anterior cerebellar vermis, lobules I-V and posterior neocortical lobules VI-VII and their relationship to sensorimotor and cognitive functions.

METHODS

Typically developing children (TDC; n=38; age 9-15) and healthy adults (HAC; n=31; 18-40) participated in high-resolution MRI. Rigorous anatomically informed morphometry of the vermis lobules I-V and VI-VII and total brain volume (TBV) employed manual segmentation computer-assisted FreeSurfer Image Analysis Program [http://surfer.nmr.mgh.harvard.edu]. The neuropsychological scores (WASI-II) were normalized and related to volumes of anterior, posterior vermis, and TBV.

RESULTS

TBVs were age independent. Volumes of I-V and VI-VII were significantly reduced in TDC. The ratio of VI-VII to I-V (∼60%) was stable across age-groups; I-V correlated with visual-spatial-motor skills; VI-VII with verbal, visual-abstract and FSIQ.

CONCLUSIONS

In TDC neither anterior I-V nor posterior VI-VII vermis attained adult volumes. The "inverted U" developmental trajectory of gray matter peaking in adolescence does not explain this finding. The hypothesis of protracted development of oligodendrocyte/myelination is suggested as a contributor to TDC's lower cerebellar vermis volumes.

Sex Differences and Behavioral Associations with Typically Developing Pediatric Regional Cerebellar Gray Matter Volume

The cerebellum contributes to motor and higher-order control throughout neurodevelopment, with marked growth during childhood. Few studies have investigated differential associations of cerebellar morphometry with function in males and females. The present study examines sex differences in regional cerebellar gray matter volume (GMV) and the moderating effect of sex on the relationship between GMV and motor, cognitive, and emotional functions in a large cohort of typically developing (TD) children. Participants included 371 TD children (123 females, age 8-12 years). A convolutional neural network-based approach was employed for cerebellar parcellation. Volumes were harmonized using ComBat to adjust for hardware-induced variations. Regression analyses examined the effect of sex on GMV and whether sex moderated the relationship between GMV and motor, cognitive, and emotional functions. Males showed larger GMV in right lobules I-V, bilateral lobules VI, crus II/VIIb, and VIII, left lobule X, and vermis regions I-V and VIII-X. Greater motor function correlated with less vermis VI-VII GMV in females. Greater cognitive function correlated with greater left lobule VI GMV in females and less left lobule VI GMV in males. Finally, greater internalizing symptoms correlated with greater bilateral lobule IX GMV in females but less in males. These findings reveal sexually dimorphic patterns of cerebellar structure and associations with motor, cognitive, and emotional functions. Males generally show larger GMV than females. Larger GMV was associated with better cognitive functioning for females and better motor/emotional functioning for males.

Ligustilide inhibits Purkinje cell ferritinophagy via the ULK1/NCOA4 pathway to attenuate valproic acid-induced autistic features

BACKGROUND

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder in which social impairment is the core symptom. Presently, there are no definitive medications to cure core symptoms of ASD, and most therapeutic strategies ameliorate ASD symptoms. Treatments with proven efficacy in autism are imminent. Ligustilide (LIG), an herbal monomer extracted from Angelica Sinensis and Chuanxiong, is mainly distributed in the cerebellum and widely used in treating neurological disorders. However, there are no studies on its effect on autistic-like phenotypes and its mechanism of action.

PURPOSE

Investigate the efficacy and mechanism of LIG in treating ASD using two Valproic acid(VPA)-exposed and BTBR T + Itpr3tf/J (BTBR) mouse models of autism.

METHODS

VPA-exposed mice and BTBR mice were given LIG for treatment, and its effect on autistic-like phenotype was detected by behavioral experiments, which included a three-chamber social test. Subsequently, RNA-Sequence(RNA-Seq) of the cerebellum was performed to observe the biological changes to search target pathways. The autophagy and ferroptosis pathways screened were verified by WB(Western Blot) assay, and the cerebellum was stained by immunofluorescence and examined by electron microscopy. To further explore the therapeutic mechanism, ULK1 agonist BL-918 was used to block the therapeutic effect of LIG to verify its target effect.

RESULTS

Our work demonstrates that LIG administration from P12-P14 improved autism-related behaviors and motor dysfunction in VPA-exposed mice. Similarly, BTBR mice showed the same improvement. RNA-Seq data identified ULK1 as the target of LIG in regulating ferritinophagy in the cerebellum of VPA-exposed mice, as evidenced by activated autophagy, increased ferritin degradation, iron overload, and lipid peroxidation. We found that VPA exposure-induced ferritinophagy occurred in the Purkinje cells, with enhanced NCOA4 and Lc3B expressions. Notably, the therapeutic effect of LIG disappeared when ULK1 was activated.

CONCLUSION

LIG treatment inhibits ferritinophagy in Purkinje cells via the ULK1/NCOA4-dependent pathway. Our study reveals for the first time that LIG treatment ameliorates autism symptoms in VPA-exposed mice by reducing aberrant Purkinje ferritinophagy. At the same time, our study complements the pathogenic mechanisms of autism and introduces new possibilities for its therapeutic options.

Roles of KCNA2 in Neurological Diseases: from Physiology to Pathology

Potassium voltage-gated channel subfamily a member 2 (Kv1.2, encoded by KCNA2) is highly expressed in the central and peripheral nervous systems. Based on the patch clamp studies, gain-of function (GOF), loss-of-function (LOF), and a mixed type (GOF/LOF) variants can cause different conditions/disorders. KCNA2-related neurological diseases include epilepsy, intellectual disability (ID), attention deficit/hyperactive disorder (ADHD), autism spectrum disorder (ASD), pain as well as autoimmune and movement disorders. Currently, the molecular mechanisms for the reported variants in causing diverse disorders are unknown. Consequently, this review brings up to date the related information regarding the structure and function of Kv1.2 channel, expression patterns, neuronal localizations, and tetramerization as well as important cell and animal models. In addition, it provides updates on human genetic variants, genotype-phenotype correlations especially highlighting the deep insight into clinical prognosis of KCNA2-related developmental and epileptic encephalopathy, mechanisms, and the potential treatment targets for all KCNA2-related neurological disorders.

Gestational Diabetes Mellitus and its Effects on the Developing Cerebellum: A Narrative Review on Experimental Studies

Diabetes mellitus during pregnancy is a common complication of gestation, but its effects on the offspring's development are poorly understood. Recently, some studies reported that gestational diabetes mellitus (GDM) impairs cerebellar development, and some genetic alterations have been described as consequences. Cerebellum, one of the hindbrain derived structures in the posterior cranial fossa, plays a crucial role in cognition and behavioral functions. In recent years, some surveys stated that gestational diabetes has adverse effects on the fetus's cerebellum. Disruption of cerebellar cortex morphogenesis, reduce the volume of the cerebellum, reduce the thickness of cerebellar cortex layers, and its neuronal cells and effects on the expression of synaptophysin, insulin, and insulin-like growth factor -1 receptors are some of the maternal diabetes effects on developing cerebellum. On other hand, GDM, as a neurotoxic agent, impaired cerebellar development and could be a cause for the behavioral, functional, and structural anomalies observed in pups of diabetic mothers. Based on the literature review, most studies have pointed out that administering insulin in patients with GDM decreased the cellular and molecular alterations that induced by GDM in the developing cerebellum. Undoubtedly, screening strategies for all pregnant women are necessary.

Single-cell multi-omics analysis of lineage development and spatial organization in the human fetal cerebellum

Human cerebellum encompasses numerous neurons, exhibiting a distinct developmental paradigm from cerebrum. Here we conducted scRNA-seq, scATAC-seq and spatial transcriptomic analyses of fetal samples from gestational week (GW) 13 to 18 to explore the emergence of cellular diversity and developmental programs in the developing human cerebellum. We identified transitory granule cell progenitors that are conserved across species. Special patterns in both granule cells and Purkinje cells were dissected multidimensionally. Species-specific gene expression patterns of cerebellar lobes were characterized and we found that PARM1 exhibited inconsistent distribution in human and mouse granule cells. A novel cluster of potential neuroepithelium at the rhombic lip was identified. We also resolved various subtypes of Purkinje cells and unipolar brush cells and revealed gene regulatory networks controlling their diversification. Therefore, our study offers a valuable multi-omics landscape of human fetal cerebellum and advances our understanding of development and spatial organization of human cerebellum.

The Role of Bcl11 Transcription Factors in Neurodevelopmental Disorders

Neurodevelopmental disorders (NDDs) comprise a diverse group of diseases, including developmental delay, autism spectrum disorder (ASD), intellectual disability (ID), and attention-deficit/hyperactivity disorder (ADHD). NDDs are caused by aberrant brain development due to genetic and environmental factors. To establish specific and curative therapeutic approaches, it is indispensable to gain precise mechanistic insight into the cellular and molecular pathogenesis of NDDs. Mutations of BCL11A and BCL11B, two closely related, ultra-conserved zinc-finger transcription factors, were recently reported to be associated with NDDs, including developmental delay, ASD, and ID, as well as morphogenic defects such as cerebellar hypoplasia. In mice, Bcl11 transcription factors are well known to orchestrate various cellular processes during brain development, for example, neural progenitor cell proliferation, neuronal migration, and the differentiation as well as integration of neurons into functional circuits. Developmental defects observed in both, mice and humans display striking similarities, suggesting Bcl11 knockout mice provide excellent models for analyzing human disease. This review offers a comprehensive overview of the cellular and molecular functions of Bcl11a and b and links experimental research to the corresponding NDDs observed in humans. Moreover, it outlines trajectories for future translational research that may help to better understand the molecular basis of Bcl11-dependent NDDs as well as to conceive disease-specific therapeutic approaches.

Identification of region-specific gene isoforms in the human brain using long-read transcriptome sequencing

In neurological and neuropsychiatric diseases, different brain regions are affected, and differences in gene expression patterns could potentially explain this mechanism. However, limited studies have precisely explored gene expression in different regions of the human brain. In this study, we performed long-read RNA sequencing on three different brain regions of the same individuals: the cerebellum, hypothalamus, and temporal cortex. Despite stringent filtering criteria excluding isoforms predicted to be artifacts, over half of the isoforms expressed in multiple samples across multiple regions were found to be unregistered in the GENCODE reference. We then especially focused on genes with different major isoforms in each brain region, even with similar overall expression levels, and identified that many of such genes including GAS7 might have distinct roles in dendritic spine and neuronal formation in each region. We also found that DNA methylation might, in part, drive different isoform expressions in different regions. These findings highlight the significance of analyzing isoforms expressed in disease-relevant sites.

Management of sleep disorders in autism spectrum disorder with co-occurring attention-deficit hyperactivity disorder: update for clinicians

AIMS

To update and examine available literature germane to the recognition, assessment and treatment of comorbid autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (ADHD) and sleep disruption, with a predominant focus on children, adolescents and emerging adults.

BACKGROUND

Considerable overlaps exist among ASD, ADHD and sleep disruption. Literature and guidance for clinicians, administrators, policy makers and families have been limited, as such deliberations were rarely considered until 2013.

METHOD

This narrative review of the literature addressing sleep disruption issues among those with ASD, ADHD and comorbid ASD and ADHD involved searching multiple databases and use of reverse citations up to the end of September 2022. Emphasis is placed on secondary sources and relevant data for clinical practice.

RESULTS

Complex clinical presentations of ASD/ADHD/sleep disruption are frequently encountered in clinical practice. Prior to 2013, prevalence, clinical presentation, pathophysiology, prognosis, other sleep-related factors and interventions were determined separately for each disorder, often with overlapping objective and subjective methods employed in the process. High percentages of ADHD and ASD patients have both disorders and sleep disruption. Here, the extant literature is integrated to provide a multidimensional understanding of the relevant issues and insights, allowing enhanced awareness and better care of this complex clinical population. Database limitations are considered.

CONCLUSIONS

Assessment of ASD symptomatology in youth with ADHD, and the reverse, in cases with disrupted sleep is critical to address the special challenges for case formulation and treatment. Evidence-based approaches to treatment planning and multi-treatment modalities should consider combining psychosocial and biological interventions to address the complexities of each case.

Visuomotor adaptation, internal modelling, and compensatory movements in children with developmental coordination disorder

BACKGROUND

Developmental coordination disorder (DCD) is one of the most prevalent developmental disorders in school-aged children. The mechanisms and etiology underlying DCD remain somewhat unclear. Altered visuomotor adaptation and internal model deficits are discussed in the literature.

AIMS

The study aimed to investigate visuomotor adaptation and internal modelling to determine whether and to what extent visuomotor learning might be impaired in children with DCD compared to typically developing children (TD). Further, possible compensatory movements during visuomotor learning were explored.

METHODS AND PROCEDURES

Participants were 12 children with DCD (age 12.4 ± 1.8, four female) and 18 age-matched TD (12.3 ± 1.8, five female). Visuomotor learning was measured with the Motor task manager. Compensatory movements were parameterized by spatial and temporal variables.

OUTCOMES AND RESULTS

Despite no differences in visuomotor adaptation or internal modelling, significant main effects for group were found in parameters representing movement accuracy, motor speed, and movement variability between DCD and TD.

CONCLUSIONS AND IMPLICATIONS

Children with DCD showed comparable performances in visuomotor adaptation and internal modelling to TD. However, movement variability was increased, whereas movement accuracy and motor speed were reduced, suggesting decreased motor acuity in children with DCD.

Modulation of Resting-State Brain Complexity After Bilateral Cerebellar Anodal Transcranial Direct Current Stimulation in Children with Autism Spectrum Disorders: a Randomized Controlled Trial Study

BACKGROUND

Autism spectrum disorders (ASD) are heterogeneous neurodevelopmental disorders characterized by aberrant neural networks. Cerebellum is best known for its role in controlling motor behaviors; however, recently, there have been significant reports showed that dysfunction in cerebellar-cerebral networks contributes significantly to many of the clinical features of ASD. Hereby, this is a randomized controlled trial (RCT) study examining the potential modulating effects of bilateral anodal tDCS stimulation over cerebellar hemispheres on the resting-state brain complexity in children with ASD.

METHODS

Thirty-six children with ASD (aged 4-14) years old were divided equally and randomly into a tDCS treatment group, which underwent 10 sessions (20-min duration, five sessions/per week) of bilateral anodal tDCS stimulation applied over left and right cerebellar hemispheres, and control group underwent the same procedures, but with sham tDCS stimulation. Resting-state brain complexity was evaluated through recording and calculating the approximate entropy (ApxEnt) values of the resting-state electroencephalograph (EEG) data obtained from a 64-channel EEG system before and after the interventions.

RESULTS

Repeated measures of ANOVA showed that tDCS had significant effects on the treatment group (Wilks' Lambda = 0.29, F (15, 16) = 2.67, p = 0.03) compared with the control group. Analyzed data showed a significant increase in the averaged ApxEnt values in the right frontal cortical region (F (1, 16) = 10.46, p = 0.005) after the bilateral cerebellar anodal tDCS stimulation. Besides, the Cohen's d effect size showed a large effect size (0.70-0.92) of bilateral cerebellar anodal tDCS on the ApxEnt values increases in the left and right frontal cortical regions, the right central cortical region, and left parietal cortical region. However, there were no any significant differences or increases in the brain complexity before and after the sham tDCS stimulation of the control group.

CONCLUSION

Bilateral cerebellar anodal tDCS modulated and increased the brain complexity in children with ASD with no any reported adverse effect. Hereby, cerebellum and cerebellar-cerebral circuitry would serve as a promising target for non-invasive brain stimulation and neuro-modulation as a therapeutic intervention.

Single-cell epigenomics and spatiotemporal transcriptomics reveal human cerebellar development

Human cerebellar development is orchestrated by molecular regulatory networks to achieve cytoarchitecture and coordinate motor and cognitive functions. Here, we combined single-cell transcriptomics, spatial transcriptomics and single cell chromatin accessibility states to systematically depict an integrative spatiotemporal landscape of human fetal cerebellar development. We revealed that combinations of transcription factors and cis-regulatory elements (CREs) play roles in governing progenitor differentiation and cell fate determination along trajectories in a hierarchical manner, providing a gene expression regulatory map of cell fate and spatial information for these cells. We also illustrated that granule cells located in different regions of the cerebellar cortex showed distinct molecular signatures regulated by different signals during development. Finally, we mapped single-nucleotide polymorphisms (SNPs) of disorders related to cerebellar dysfunction and discovered that several disorder-associated genes showed spatiotemporal and cell type-specific expression patterns only in humans, indicating the cellular basis and possible mechanisms of the pathogenesis of neuropsychiatric disorders.

Experience of early-life pain in premature infants is associated with atypical cerebellar development and later neurodevelopmental deficits

BACKGROUND

Infants born very and extremely premature (V/EPT) are at a significantly elevated risk for neurodevelopmental disorders and delays even in the absence of structural brain injuries. These risks may be due to earlier-than-typical exposure to the extrauterine environment, and its bright lights, loud noises, and exposures to painful procedures. Given the relative underdeveloped pain modulatory responses in these infants, frequent pain exposures may confer risk for later deficits.

METHODS

Resting-state fMRI scans were collected at term equivalent age from 148 (45% male) infants born V/EPT and 99 infants (56% male) born at term age. Functional connectivity analyses were performed between functional regions correlating connectivity to the number of painful skin break procedures in the NICU, including heel lances, venipunctures, and IV placements. Subsequently, preterm infants returned at 18 months, for neurodevelopmental follow-up and completed assessments for autism risk and general neurodevelopment.

RESULTS

We observed that V/EPT infants exhibit pronounced hyperconnectivity within the cerebellum and between the cerebellum and both limbic and paralimbic regions correlating with the number of skin break procedures. Moreover, skin breaks were strongly associated with autism risk, motor, and language scores at 18 months. Subsample analyses revealed that the same cerebellar connections strongly correlating with breaks at term age were associated with language dysfunction at 18 months.

CONCLUSIONS

These results have significant implications for the clinical care of preterm infants undergoing painful exposures during routine NICU care, which typically occurs without anesthesia. Repeated pain exposures appear to have an increasingly detrimental effect on brain development during a critical period, and effects continue to be seen even 18 months later.

Review of short-term and long-term adverse effects of covid-19 vaccination during pregnancy

BACKGROUND

The covid-19 pandemic sparked a debate about the safety of vaccines during pregnancy. However, pregnant women were excluded from the Pfizer-BioNTech vaccine phase 3 trials. As two years have passed since the first Covid-19 vaccine and more studies have been conducted, we want to evaluate the scientific literature to determine any actual risks in taking the vaccine during pregnancy.

METHODS

We conducted literature research using PubMed and Google Scholar databases from January to April 2023. As the review considers short- and long-term adverse effects it was divided into two parts. The first part was conducted as a systematic review. The second concerning long-term negative effects due to lack of research is a literature review. The inclusion criteria for the systematic review part were singleton pregnancies, women vaccinated during pregnancy, and studies from 2020 and later. The most common short-term pregnancy adverse effects were included in the search: preterm delivery, small gestation age, intrauterine death, congenital defects, stillborn, fetal growth retardation, spontaneous abortion. Maternal immune activation was the primary concern for the long-term adverse effects and whether vaccination could cause it. The search terms included maternal immune activation, fetal neurodevelopment, neuropsychiatric disorders and the studies used were from 2019.

RESULTS

Most studies showed no significant difference in short-term adverse effects between vaccinated and non-vaccinated women and their fetuses. However, the literature is insufficient to evaluate possible long-term adverse effects.

CONCLUSION

Available evidence supports the safety of administering SARS-CoV-2 vaccines to pregnant women, but further systematic reviews and meta-analyses are essential. Maternal immune activation caused by vaccination may impact a child's neurodevelopment and should be a concern for future studies.

IL-4 shapes microglia-dependent pruning of the cerebellum during postnatal development

Interleukin-4 (IL-4) is a type 2 cytokine with pleiotropic functions in adaptive immunity, allergies, and cognitive processes. Here, we show that low levels of IL-4 in the early postnatal stage delineate a critical period in which microglia extensively prune cerebellar neurons. Elevating the levels of this cytokine via peripheral injection, or using a mouse model of allergic asthma, leads to defective pruning, permanent increase in cerebellar granule cells, and circuit alterations. These animals also show a hyperkinetic and impulsive-like phenotype, reminiscent of attention-deficit hyperactivity disorder (ADHD). These alterations are blocked in Il4rαfl/fl::Cx3cr1-CreER mice, which are deficient in IL-4 receptor signaling in microglia. These findings demonstrate a previously unknown role for IL-4 during a neuroimmune critical period of cerebellar maturation and provide a first putative mechanism for the comorbidity between allergic disease and ADHD observed in humans.

Alterations in Serotonin Neurotransmission in Hyperdopaminergic Rats Lacking the Dopamine Transporter

Biogenic amines dopamine (DA) and serotonin (5-HT) are among the most significant monoaminergic neurotransmitters in the central nervous system (CNS). Separately, the physiological roles of DA and 5-HT have been studied in detail, and progress has been made in understanding their roles in normal and various pathological conditions (Parkinson's disease, schizophrenia, addiction, depression, etc.). In this article we showed that knockout of the gene encoding DAT leads not only to a profound dysregulation of dopamine neurotransmission in the striatum but also in the midbrain, prefrontal cortex, hippocampus, medulla oblongata and spinal cord. Furthermore, significant changes were observed in the production of mRNA of enzymes of monoamine metabolism, as well as to a notable alteration in the tissue level of serotonin, most clearly manifested in the cerebellum and the spinal cord. The observed region-specific changes in the tissue levels of serotonin and in the expression of dopamine and serotonergic metabolism enzymes in rats with an excess of dopamine can indicate important consequences for the pharmacotherapy of drugs that modulate the dopaminergic system. The drugs that affect the dopaminergic system could potently affect the serotonergic system, and this fact is important to consider when predicting their possible therapeutic or side effects.

Risks Associated With Undiagnosed ADHD and/or Autism: A Mixed-Method Systematic Review

BACKGROUND

The two most prevalent neurodevelopmental disorders-Attention Deficit Hyperactivity Disorder (ADHD) and Autism (ASD)-(ASD/ADHD) strongly impact individuals' functions. This is worsened when individuals are undiagnosed and risks such as increased imprisonments, depression or drug misuse are often observed. This systematic review synthesizes the risks associated with late/undiagnosed ASD/ADHD.

METHODS

Four databases were searched (Medline, Scopus, PsychInfor, and Embase). Published studies exploring the impact of undiagnosed ASD/ADHD were included. Exclusion criteria included, lack of diagnosis status, studies not solely on ASD or ADHD, gray literature and studies not in English. The findings were summarize through a narrative synthesis.

RESULTS

Seventeen studies were identified, 14 on ADHD and three on ASD. The narrative synthesis identified three main themes: (1) Health, (2) Offending behavior, and (3) Day-to-day impact. The risks highlighted a significant impact on mental wellbeing and social interactions, higher risks of substance abuse, accidents and offending behavior as well as lower levels of income and education.

DISCUSSION

The findings suggest that undiagnosed ASD/ADHD is linked to many risks and negative outcomes affecting individuals, their families, and the wider society. The restricted number of studies on ASD are a limitation to the generalization of these findings Implications for research and practice are discussed, highlighting the importance of screening and acknowledging the possibility of ASD/ADHD in many settings such as psychiatric and forensic.

An Overview on Electrophysiological and Neuroimaging Findings in Dyslexia

Objective: Dyslexia is a prevalent neurodevelopmental condition that is characterized by inaccurate and slow word recognition. This article reviews neural correlates of dyslexia from both electrophysiological and neuroimaging studies. Method : In this brief review, we provide electrophysiological and neuroimaging evidence from electroencephalogram (EEG) and magnetic resonance imaging (MRI) studies in dyslexia to understand functional and structural brain changes in this condition. Results: In both electrophysiological and neuroimaging studies, the most frequently reported functional impairments in dyslexia include aberrant activation of the left hemisphere occipito-temporal cortex (OTC), temporo-parietal cortex (TPC), inferior frontal gyrus (IFG), and cerebellar areas. EEG studies have mostly highlighted the important role of lower frequency bands in dyslexia, especially theta waves. Furthermore, neuroimaging studies have suggested that dyslexia is related to functional and structural impairments in the left hemisphere regions associated with reading and language, including reduced grey matter volume in the left TPC, decreased white matter connectivity between reading networks, and hypo-activation of the left OTC and TPC. In addition, neural evidence from pre-reading children and infants at risk for dyslexia show that there are abnormalities in the dyslexic brain before learning to read begins. Conclusion: Advances in comprehending the neural correlates of dyslexia could bring closer translation from basic to clinical neuroscience and effective rehabilitation for individuals who struggle to read. However, neuroscience still has great potential for clinical translation that requires further research.

Associative gene networks reveal novel candidates important for ADHD and dyslexia comorbidity

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is commonly associated with developmental dyslexia (DD), which are both prevalent and complicated pediatric neurodevelopmental disorders that have a significant influence on children's learning and development. Clinically, the comorbidity incidence of DD and ADHD is between 25 and 48%. Children with DD and ADHD may have more severe cognitive deficiencies, a poorer level of schooling, and a higher risk of social and emotional management disorders. Furthermore, patients with this comorbidity are frequently treated for a single condition in clinical settings, and the therapeutic outcome is poor. The development of effective treatment approaches against these diseases is complicated by their comorbidity features. This is often a major problem in diagnosis and treatment. In this study, we developed bioinformatical methodology for the analysis of the comorbidity of these two diseases. As such, the search for candidate genes related to the comorbid conditions of ADHD and DD can help in elucidating the molecular mechanisms underlying the comorbid condition, and can also be useful for genotyping and identifying new drug targets.

RESULTS

Using the ANDSystem tool, the reconstruction and analysis of gene networks associated with ADHD and dyslexia was carried out. The gene network of ADHD included 599 genes/proteins and 148,978 interactions, while that of dyslexia included 167 genes/proteins and 27,083 interactions. When the ANDSystem and GeneCards data were combined, a total of 213 genes/proteins for ADHD and dyslexia were found. An approach for ranking genes implicated in the comorbid condition of the two diseases was proposed. The approach is based on ten criteria for ranking genes by their importance, including relevance scores of association between disease and genes, standard methods of gene prioritization, as well as original criteria that take into account the characteristics of an associative gene network and the presence of known polymorphisms in the analyzed genes. Among the top 20 genes with the highest priority DRD2, DRD4, CNTNAP2 and GRIN2B are mentioned in the literature as directly linked with the comorbidity of ADHD and dyslexia. According to the proposed approach, the genes OPRM1, CHRNA4 and SNCA had the highest priority in the development of comorbidity of these two diseases. Additionally, it was revealed that the most relevant genes are involved in biological processes related to signal transduction, positive regulation of transcription from RNA polymerase II promoters, chemical synaptic transmission, response to drugs, ion transmembrane transport, nervous system development, cell adhesion, and neuron migration.

CONCLUSIONS

The application of methods of reconstruction and analysis of gene networks is a powerful tool for studying the molecular mechanisms of comorbid conditions. The method put forth to rank genes by their importance for the comorbid condition of ADHD and dyslexia was employed to predict genes that play key roles in the development of the comorbid condition. The results can be utilized to plan experiments for the identification of novel candidate genes and search for novel pharmacological targets.

Vestibular Evaluation of Children Diagnosed with Specific Learning Disorder

Objective

The aim of this study was to determine the vestibular function of children diagnosed with specific learning disorders (SLD).

Methods

This study was conducted with 30 children diagnosed with SLD and 30 healthy children matched for age and sex, and vestibular tests were applied.

Results

Optokinetic and head shake test values in videonystagmography subtests were found to be pathological in the study group, and the lateral asymmetry value in video head impulse test (v-HIT) was found to be significantly higher in the study group. Also, a significant difference was found in the N1 latency, P1-N1 interlatency, P1-N1 amplitude values in the cervical vestibular evoked myogenic potential test, and asymmetry values in the ocular vestibular evoked myogenic potential test.

Conclusion

The current study showed that vestibular functions may differ from normal in SLD patients and that vestibular dysfunction may play a role in symptoms such as postural instability, balance, and gross and fine motor disorders that are frequently observed in these children.

Resting-state functional connectivity-based parcellation of the human dentate nucleus: new findings and clinical relevance

For years, the cerebellum was left out of functional magnetic resonance imaging (fMRI) studies due to technological limitations. The advent of novel data acquisition and reconstruction strategies (e.g., whole-brain simultaneous multi-slice imaging) employing multi-channel array coils has overcome such limitations, ushering unprecedented improvements in temporal signal-to-noise ratio and spatiotemporal resolution. Here, we aim to provide a brief report on the deep cerebellar nuclei, specifically focusing on the dentate nuclei, the primary output nuclei, situated within both cognitive and motor cerebello-cerebral circuits. We highlight the importance of functional parcellation in refining our understanding of broad resting-state functional connectivity (RSFC) in both health and disease. First, we review work relevant to the functional topography of the dentate nuclei, including recent advances in functional parcellation. Next, we review RSFC studies using the dentate nuclei as seed regions of interest in neurological and psychiatric populations and discuss the potential benefits of applying functionally defined subdivisions. Finally, we discuss recent technological advances and underscore ultrahigh-field neuroimaging as a tool to potentiate functionally parcellated RSFC analyses in clinical populations.

Consistent estimation of the number of communities via regularized network embedding

The network analysis plays an important role in numerous application domains including biomedicine. Estimation of the number of communities is a fundamental and critical issue in network analysis. Most existing studies assume that the number of communities is known a priori, or lack of rigorous theoretical guarantee on the estimation consistency. In this paper, we propose a regularized network embedding model to simultaneously estimate the community structure and the number of communities in a unified formulation. The proposed model equips network embedding with a novel composite regularization term, which pushes the embedding vector toward its center and pushes similar community centers collapsed with each other. A rigorous theoretical analysis is conducted, establishing asymptotic consistency in terms of community detection and estimation of the number of communities. Extensive numerical experiments have also been conducted on both synthetic networks and brain functional connectivity network, which demonstrate the superior performance of the proposed method compared with existing alternatives.

Sex difference contributes to phenotypic diversity in individuals with neurodevelopmental disorders

Objective

Gain a better understanding of sex-specific differences in individuals with global developmental delay (GDD), with a focus on phenotypes and genotypes.

Methods

Using the Deciphering Developmental Disorders (DDD) dataset, we extracted phenotypic information from 6,588 individuals with GDD and then identified statistically significant variations in phenotypes and genotypes based on sex. We compared genes with pathogenic variants between sex and then performed gene network and molecular function enrichment analysis and gene expression profiling between sex. Finally, we contrasted individuals with autism as an associated condition.

Results

We identified significantly differentially expressed phenotypes in males vs. females individuals with GDD. Autism and macrocephaly were significantly more common in males whereas microcephaly and stereotypies were more common in females. Importantly, 66% of GDD genes with pathogenic variants overlapped between both sexes. In the cohort, males presented with only slightly increased X-linked genes (9% vs. 8%, respectively). Individuals from both sexes harbored a similar number of pathogenic variants overall (3) but females presented with a significantly higher load for GDD genes with high intolerance to loss of function. Sex difference in gene expression correlated with genes identified in a sex specific manner. While we identified sex-specific GDD gene mutations, their pathways overlapped. Interestingly, individuals with GDD but also co-morbid autism phenotypes, we observed distinct mutation load, pathways and phenotypic presentation.

Conclusion

Our study shows for the first time that males and females with GDD present with significantly different phenotypes. Moreover, while most GDD genes overlapped, some genes were found uniquely in each sex. Surprisingly they shared similar molecular functions. Sorting genes by predicted tolerance to loss of function (pLI) led to identifying an increased mutation load in females with GDD, suggesting potentially a tolerance to GDD genes of higher pLI compared to overall GDD genes. Finally, we show that considering associated conditions (for instance autism) may influence the genomic underpinning found in individuals with GDD and highlight the importance of comprehensive phenotyping.

Microstructural Properties of the Cerebellar Peduncles in Children with Developmental Language Disorder

Children with developmental language disorder (DLD) struggle to learn their native language for no apparent reason. While research on the neurobiological underpinnings of the disorder has focused on the role of cortico-striatal systems, little is known about the role of the cerebellum in DLD. Cortico-cerebellar circuits might be involved in the disorder as they contribute to complex sensorimotor skill learning, including the acquisition of spoken language. Here, we used diffusion-weighted imaging data from 77 typically developing and 54 children with DLD and performed probabilistic tractography to identify the cerebellum's white matter tracts: the inferior, middle, and superior cerebellar peduncles. Children with DLD showed lower fractional anisotropy (FA) in the inferior cerebellar peduncles (ICP), fiber tracts that carry motor and sensory input via the inferior olive to the cerebellum. Lower FA in DLD was driven by lower axial diffusivity. Probing this further with more sophisticated modeling of diffusion data, we found higher orientation dispersion but no difference in neurite density in the ICP of DLD. Reduced FA is therefore unlikely to be reflecting microstructural differences in myelination in this tract, rather the organization of axons in these pathways is disrupted. ICP microstructure was not associated with language or motor coordination performance in our sample. We also found no differences in the middle and superior peduncles, the main pathways connecting the cerebellum with the cortex. To conclude, it is not cortico-cerebellar but atypical olivocerebellar white matter connections that characterize DLD and suggest the involvement of the olivocerebellar system in speech acquisition and development.

Neuropsychiatric outcomes following strokes involving the cerebellum: a retrospective cohort study

Introduction

Given the wide-ranging involvement of cerebellar activity in motor, cognitive, and affective functions, clinical outcomes resulting from cerebellar damage can be hard to predict. Cerebellar vascular accidents are rare, comprising less than 5% of strokes, yet this rare patient population could provide essential information to guide our understanding of cerebellar function.

Methods

To gain insight into which domains are affected following cerebellar damage, we retrospectively examined neuropsychiatric performance following cerebellar vascular accidents in cases registered on a database of patients with focal brain injuries. Neuropsychiatric testing included assessment of cognitive (working memory, language processing, and perceptual reasoning), motor (eye movements and fine motor control), and affective (depression and anxiety) domains.

Results

Results indicate that cerebellar vascular accidents are more common in men and starting in the 5th decade of life, in agreement with previous reports. Additionally, in our group of twenty-six patients, statistically significant performance alterations were not detected at the group level an average of 1.3 years following the vascular accident. Marginal decreases in performance were detected in the word and color sub-scales of the Stroop task, the Rey Auditory Verbal Learning Test, and the Lafayette Grooved Pegboard Test.

Discussion

It is well established that the acute phase of cerebellar vascular accidents can be life-threatening, largely due to brainstem compression. In the chronic phase, our findings indicate that recovery of cognitive, emotional, and affective function is likely. However, a minority of individuals may suffer significant long-term performance impairments in motor coordination, verbal working memory, and/or linguistic processing.

Motor Capabilities in Children with ADHD Are Improved after Brief Visuopostural Training

Children with ADHD show poor motor control. The aim of the present study was to test whether children with ADHD improved their motor performances (oculomotor as well as posture) after a short visuopostural training period. Two groups (G1 trained and G2 non-trained), each comprising 15 children with ADHD matched in IQ (intelligence quotient), sex, and age, participated in the study. Eye movements and postural sway were measured before (T1) and after (T2) 10 min of visuopostural training for the trained group and after 10 min of resting for the non-trained group. Training consisted of a visual search task performed while the child was standing on an unstable platform. At T1, oculomotor and postural abilities were statistically similar for both groups of children with ADHD (trained and non-trained). At T2, significant improvements in both oculomotor and postural capabilities were observed for the trained group but not for the non-trained group. These findings suggest that a short visuopostural training period could help children with ADHD to learn how to focus their visual attention in order to improve motor performance. Visuopostural training could allow a better integration of sensory inputs via central mechanisms, leading to improvement in both oculomotor and postural control. Further studies on a larger number of children with ADHD will be needed to confirm these findings and explore the eventual possible persistence of the training effect.

Neurocognitive and cerebellar function in ADHD, autism and spinocerebellar ataxia

The cerebellum plays a major role in balance, motor control and sensorimotor integration, but also in cognition, language, and emotional regulation. Several neuropsychiatric disorders such as attention deficit-hyperactivity disorder (ADHD), autism spectrum disorder (ASD), as well as neurological diseases such as spinocerebellar ataxia type 3 (SCA3) are associated with differences in cerebellar function. Morphological abnormalities in different cerebellar subregions produce distinct behavioral symptoms related to the functional disruption of specific cerebro-cerebellar circuits. The specific contribution of the cerebellum to typical development may therefore involve the optimization of the structure and function of cerebro-cerebellar circuits underlying skill acquisition in multiple domains. Here, we review cerebellar structural and functional differences between healthy and patients with ADHD, ASD, and SCA3, and explore how disruption of cerebellar networks affects the neurocognitive functions in these conditions. We discuss how cerebellar computations contribute to performance on cognitive and motor tasks and how cerebellar signals are interfaced with signals from other brain regions during normal and dysfunctional behavior. We conclude that the cerebellum plays a role in many cognitive functions. Still, more clinical studies with the support of neuroimaging are needed to clarify the cerebellum's role in normal and dysfunctional behavior and cognitive functioning.

Abnormal volumetric brain morphometry and cerebral blood flow in adolescents with depression

BACKGROUND

Prior research has demonstrated that the brains of adolescents with depression exhibit distinct structural alterations. However, preliminary studies have documented the pathophysiological changes in certain brain regions, such as the cerebellum, highlighting a need for further research to support the current understanding of this disease.

AIM

To study brain changes in depressed adolescents.

METHODS

This study enrolled 34 adolescents with depression and 34 age-, sex-, and education-level-matched healthy control (HC) individuals. Structural and functional alterations were identified when comparing the brains of these two participant groups through voxel-based morphometry and cerebral blood flow (CBF) analysis, respectively. Associations between identified brain alterations and the severity of depressive symptoms were explored through Pearson correlation analyses.

RESULTS

The cerebellum, superior frontal gyrus, cingulate gyrus, pallidum, middle frontal gyrus, angular gyrus, thalamus, precentral gyrus, inferior temporal gyrus, superior temporal gyrus, inferior frontal gyrus, and supplementary motor areas of adolescents with depression showed an increase in brain volume compared to HC individuals. These patients with depression further presented with a pronounced drop in CBF in the left pallidum (group = 98, and peak t = - 4.4324), together with increased CBF in the right percental gyrus (PerCG) (group = 90, and peak t = 4.5382). In addition, 17-item Hamilton Depression Rating Scale scores were significantly correlated with the increased volume in the opercular portion of the left inferior frontal gyrus (r = - 0.5231, P < 0.01).

CONCLUSION

The right PerCG showed structural and CBF changes, indicating that research on this part of the brain could offer insight into the pathophysiological causes of impaired cognition.

Posterior Fossa Sub-Arachnoid Cysts Observed in Patients with Bipolar Disorder: a Retrospective Cohort Study

Posterior fossa arachnoid cysts (PFACs) are rare congenital abnormalities observed in 0.3 to 1.7% of the population and are traditionally thought to be benign. While conducting a neuroimaging study investigating cerebellar structure in bipolar disorder, we observed a higher incidence of PFACs in bipolar patients (5 of 75; 6.6%) compared to the neuronormative control group (1 of 54; 1.8%). In this report, we detail the cases of the five patients with bipolar disorder who presented with PFACs. Additionally, we compare neuropsychiatric measures and cerebellar volumes of these patients to neuronormative controls and bipolar controls (those with bipolar disorder without neuroanatomical abnormalities). Our findings suggest that patients with bipolar disorder who also present with PFACs may have a milder symptom constellation relative to patients with bipolar disorder and no neuroanatomical abnormalities. Furthermore, our observations align with prior literature suggesting an association between PFACs and psychiatric symptoms that warrants further study. While acknowledging sample size limitations, our primary aim in the present work is to highlight a connection between PFACs and BD-associated symptoms and encourage further study of cerebellar abnormalities in psychiatry.

Diagnosis of autism spectrum disorder based on functional brain networks and machine learning

Autism is a multifaceted neurodevelopmental condition whose accurate diagnosis may be challenging because the associated symptoms and severity vary considerably. The wrong diagnosis can affect families and the educational system, raising the risk of depression, eating disorders, and self-harm. Recently, many works have proposed new methods for the diagnosis of autism based on machine learning and brain data. However, these works focus on only one pairwise statistical metric, ignoring the brain network organization. In this paper, we propose a method for the automatic diagnosis of autism based on functional brain imaging data recorded from 500 subjects, where 242 present autism spectrum disorder considering the regions of interest throughout Bootstrap Analysis of Stable Cluster map. Our method can distinguish the control group from autism spectrum disorder patients with high accuracy. Indeed the best performance provides an AUC near 1.0, which is higher than that found in the literature. We verify that the left ventral posterior cingulate cortex region is less connected to an area in the cerebellum of patients with this neurodevelopment disorder, which agrees with previous studies. The functional brain networks of autism spectrum disorder patients show more segregation, less distribution of information across the network, and less connectivity compared to the control cases. Our workflow provides medical interpretability and can be used on other fMRI and EEG data, including small data sets.

Building better brains: the pleiotropic function of neurotrophic factors in postnatal cerebellar development

The cerebellum is a multifunctional brain region that controls diverse motor and non-motor behaviors. As a result, impairments in the cerebellar architecture and circuitry lead to a vast array of neuropsychiatric and neurodevelopmental disorders. Neurotrophins and neurotrophic growth factors play essential roles in the development as well as maintenance of the central and peripheral nervous system which is crucial for normal brain function. Their timely expression throughout embryonic and postnatal stages is important for promoting growth and survival of both neurons and glial cells. During postnatal development, the cerebellum undergoes changes in its cellular organization, which is regulated by a variety of molecular factors, including neurotrophic factors. Studies have shown that these factors and their receptors promote proper formation of the cerebellar cytoarchitecture as well as maintenance of the cerebellar circuits. In this review, we will summarize what is known on the neurotrophic factors' role in cerebellar postnatal development and how their dysregulation assists in developing various neurological disorders. Understanding the expression patterns and signaling mechanisms of these factors and their receptors is crucial for elucidating their function within the cerebellum and for developing therapeutic strategies for cerebellar-related disorders.

Protective Effect of Dexmedetomidine against Hyperoxia-Damaged Cerebellar Neurodevelopment in the Juvenile Rat

Impaired cerebellar development of premature infants and the associated impairment of cerebellar functions in cognitive development could be crucial factors for neurodevelopmental disorders. Anesthetic- and hyperoxia-induced neurotoxicity of the immature brain can lead to learning and behavioral disorders. Dexmedetomidine (DEX), which is associated with neuroprotective properties, is increasingly being studied for off-label use in the NICU. For this purpose, six-day-old Wistar rats (P6) were exposed to hyperoxia (80% O₂) or normoxia (21% O₂) for 24 h after DEX (5 µg/kg, i.p.) or vehicle (0.9% NaCl) application. An initial detection in the immature rat cerebellum was performed after the termination of hyperoxia at P7 and then after recovery in room air at P9, P11, and P14. Hyperoxia reduced the proportion of Calb1+-Purkinje cells and affected the dendrite length at P7 and/or P9/P11. Proliferating Pax6+-granule progenitors remained reduced after hyperoxia and until P14. The expression of neurotrophins and neuronal transcription factors/markers of proliferation, migration, and survival were also reduced by oxidative stress in different manners. DEX demonstrated protective effects on hyperoxia-injured Purkinje cells, and DEX without hyperoxia modulated neuronal transcription in the short term without any effects at the cellular level. DEX protects hyperoxia-damaged Purkinje cells and appears to differentially affect cerebellar granular cell neurogenesis following oxidative stress.

Altered cerebellar lobular volumes correlate with clinical deficits in siblings and children with ASD: evidence from toddlers

BACKGROUND

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by impaired social and communication skills, narrow interests, and repetitive behavior. It is known that the cerebellum plays a vital role in controlling movement and gait posture. However, recently, researchers have reported that the cerebellum may also be responsible for other functions, such as social cognition, reward, anxiety, language, and executive functions.

METHODS

In this study, we ascertained volumetric differences from cerebellar lobular analysis from children with ASD, ASD siblings, and typically developing healthy controls. In this cross-sectional study, a total of 30 children were recruited, including children with ASD (N = 15; mean age = 27.67 ± 5.1 months), ASD siblings (N = 6; mean age = 17.5 ± 3.79 months), and typically developing children (N = 9; mean age = 17.67 ± 3.21 months). All the MRI data was acquired under natural sleep without using any sedative medication. We performed a correlation analysis with volumetric data and developmental and behavioral measures obtained from these children. Two-way ANOVA and Pearson correlation was performed for statistical data analysis.

RESULTS

We observed intriguing findings from this study, including significantly increased gray matter lobular volumes in multiple cerebellar regions including; vermis, left and right lobule I-V, right CrusII, and right VIIb and VIIIb, respectively, in children with ASD, compared to typically developing healthy controls and ASD siblings. Multiple cerebellar lobular volumes were also significantly correlated with social quotient, cognition, language, and motor scores with children with ASD, ASD siblings, and healthy controls, respectively.

CONCLUSIONS

This research finding helps us understand the neurobiology of ASD and ASD-siblings, and critically advances current knowledge about the cerebellar role in ASD. However, results need to be replicated for a larger cohort from longitudinal research study in future.

3D reconstruction of the cerebellar germinal layer reveals tunneling connections between developing granule cells

The difficulty of retrieving high-resolution, in vivo evidence of the proliferative and migratory processes occurring in neural germinal zones has limited our understanding of neurodevelopmental mechanisms. Here, we used a connectomic approach using a high-resolution, serial-sectioning scanning electron microscopy volume to investigate the laminar cytoarchitecture of the transient external granular layer (EGL) of the developing cerebellum, where granule cells coordinate a series of mitotic and migratory events. By integrating image segmentation, three-dimensional reconstruction, and deep-learning approaches, we found and characterized anatomically complex intercellular connections bridging pairs of cerebellar granule cells throughout the EGL. Connected cells were either mitotic, migratory, or transitioning between these two cell stages, displaying a chronological continuum of proliferative and migratory events never previously observed in vivo at this resolution. This unprecedented ultrastructural characterization poses intriguing hypotheses about intercellular connectivity between developing progenitors and its possible role in the development of the central nervous system.

Cerebellar gamma-aminobutyric acid: Investigation of group effects in neurodevelopmental disorders

Neurodevelopmental disorders (NDDs) including autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD) are thought to arise in part from the disruption in the excitatory/inhibitory balance of gamma-aminobutyric acid (GABA) and glutamate in the brain. Recent evidence has shown the involvement of the cerebellum in cognition and affect regulation, and cerebellar atypical function or damage is reported frequently in NDDs. Magnetic resonance spectroscopy studies have reported decreases in GABA in cortical brain areas in the NDDs, however, GABA levels in the cerebellum have not been examined. To determine possible group effects, we used a MEGA-PRESS acquisition to investigate GABA+ levels in a cerebellar voxel in 343 individuals (aged 2.5-22 years) with ASD, ADHD, OCD and controls. Using a mixed effects model, we found no significant differences between groups in GABA+ concentration. Our findings suggest that cerebellar GABA+ levels do not differentiate NDD groups.

Cerebellar network changes in depressed patients with and without autism spectrum disorder: A case-control study

Pathophysiological difference of depression in patients with and without autistic spectrum disorder (ASD) has not been investigated previously. Therefore, we sought to determine whether there were differences between non-ASD and ASD groups on resting-state functional magnetic resonance imaging (rs-fMRI) in patients with depression. We performed 3T MRI under resting state in 8 patients with depression and ASD and 12 patients with depression but without ASD. The ASD group showed increased functional connectivity in the cerebellar network of the left posterior inferior temporal gyrus and anterior cerebellar lobes compared to the non-ASD group in an analysis of covariance. Adding antipsychotics, antidepressants, benzodiazepines, nonbenzodiazepines, anxiolytics, hypnotics, or age as covariates showed a similar increase in functional connectivity. Thus, this study found that depressive patients with ASD had increased functional connectivity in the cerebellar network. Our findings suggest that fMRI may be able to evaluate differences in depressed patients with and without ASD.

A data-fusion approach to identifying developmental dyslexia from multi-omics datasets

This exploratory study tested and validated the use of data fusion and machine learning techniques to probe high-throughput omics and clinical data with a goal of exploring the etiology of developmental dyslexia. Developmental dyslexia is the leading learning disability in school aged children affecting roughly 5-10% of the US population. The complex biological and neurological phenotype of this life altering disability complicates its diagnosis. Phenome, exome, and metabolome data was collected allowing us to fully explore this system from a behavioral, cellular, and molecular point of view. This study provides a proof of concept showing that data fusion and ensemble learning techniques can outperform traditional machine learning techniques when provided small and complex multi-omics and clinical datasets. Heterogenous stacking classifiers consisting of single-omic experts/models achieved an accuracy of 86%, F1 score of 0.89, and AUC value of 0.83. Ensemble methods also provided a ranked list of important features that suggests exome single nucleotide polymorphisms found in the thalamus and cerebellum could be potential biomarkers for developmental dyslexia and heavily influenced the classification of DD within our machine learning models.

Disruption of protein geranylgeranylation in the cerebellum causes cerebellar hypoplasia and ataxia via blocking granule cell progenitor proliferation

The prenylation of proteins is involved in a variety of biological functions. However, it remains unknown whether it plays an important role in the morphogenesis of the cerebellum. To address this question, we generated a mouse model, in which the geranylgeranyl pyrophosphate synthase (Ggps1) gene is inactivated in neural progenitor cells in the developing cerebellum. We report that conditional knockout (cKO) of Ggps1 leads to severe ataxia and deficient locomotion. To identify the underlying mechanisms, we completed a series of cellular and molecular experiments. First, our morphological analysis revealed significantly decreased population of granule cell progenitors (GCPs) and impaired proliferation of GCPs in the developing cerebellum of Ggps1 cKO mice. Second, our molecular analysis showed increased expression of p21, an important cell cycle regulator in Ggps1 cKO mice. Together, this study highlights a critical role of Ggpps-dependent protein prenylation in the proliferation of cerebellar GCPs during cerebellar development.

Cerebellar Hypoperfusion in Two Patients with Cornelia de Lange Syndrome with Novel NIPBL Variants

Introduction

Cornelia de Lange syndrome (CdLS) is a rare congenital malformation characterized by distinctive facial features, short stature, and limb defects. In addition, half of the patients with CdLS exhibit repetitive self-injurious behaviors (SIBs) related to intellectual disability with autistic traits. CdLS is caused by pathogenic variants of genes encoding the cohesin complex pathway, with 70% of these variants identified in the nipped-B-like (NIPBL) gene.

Case Presentation

We report 2 patients with CdLS who exhibited repetitive SIBs. Patient 1, a 40-year-old male, carried a novel heterozygous duplication variant, c.1458dup, p.(Glu487*), in exon 9 of the NIPBL gene. Patient 2, a 49-year-old female, carried a novel heterozygous insertion variant, c.1751_1752ins[A;1652_1751], p.(Asp584Glufs*8), in exon 10 of the NIPBL gene. These variants were predicted to confer loss of function to the protein because of a premature stop codon. In both patients, single-photon emission computed tomography using N-isopropyl-p-[123I] iodoamphetamine (IMP-SPECT) revealed diffuse hypoperfusion in the cerebellum.

Discussion

This report identified 2 novel pathogenic variants in the NIPBL gene and the relationship between SIBs and cerebellar hypoperfusion in patients with CdLS. The cerebellar hypoperfusion might have been caused by the dysfunction of the cohesin complex via the downregulation of the NIPBL gene products. Further studies should be conducted to elucidate the contribution of the NIPBL gene to the development of the cerebello-cerebral cortical circuits associated with behavioral disorders.

Mindful Movement Intervention Applied to at Risk Urban School Children for Improving Motor, Cognitive, and Emotional-Behavioral Regulation

Objectives

Preliminary evidence has supported the notion that mindful movement-based practices may offer benefits for self-regulation, particularly for vulnerable children. However, this evidence has principally stemmed from subjective assessments of behavioral change, leaving the underlying mechanisms undetermined. The present study aimed to investigate the efficacy of an in-school mindful movement intervention (MMI) for at-risk children within an urban public school for enhancing motor, cognitive, and emotional-behavioral regulation, including control of disruptive and inattentive behaviors characteristic of ADHD.

Method

Participants included 38 (age 7-8 years) children who received twice weekly, in-school MMI, including a modified Tai Chi sequence, yoga and biomechanical warm-ups, imaginative play, and reflection. Parent and teacher ratings of disruptive behaviors, and objective measures of motor and cognitive control, were collected at baseline and after 5 months of MMI.

Results

Significant improvements in teacher ratings of inattentive, hyperactive/impulsive, oppositional, and other disruptive behaviors were observed. Significant improvements were also observed for objective measures of both cognitive control and motor control with particular reductions in both right and left dysrhythmia.

Conclusions

MMI was associated with improvements across objective and subjective assessments of motor, cognitive, and behavioral control. This proof-of-principle investigation provides preliminary support for the efficacy and feasibility of a novel MMI implemented as part of the school day in an urban school setting with 7-8-year-old children to augment development of at-risk youth.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12671-022-02063-7.

Meta-analytic connectivity modelling of functional magnetic resonance imaging studies in autism spectrum disorders

Social and non-social deficits in autism spectrum disorders (ASD) persist into adulthood and may share common regions of aberrant neural activations. The current meta-analysis investigated activation differences between ASD and neurotypical controls irrespective of task type. Activation likelihood estimation meta-analyses were performed to examine consistent hypo-activated and/or hyper-activated regions for all tasks combined, and for social and non-social tasks separately; meta-analytic connectivity modelling and behavioral/paradigm analyses were performed to examine co-activated regions and associated behaviors. One hundred studies (mean age range = 18-41 years) were included. For all tasks combined, the ASD group showed significant (p < .05) hypo-activation in one cluster around the left amygdala (peak - 26, -2, -20, volume = 1336 mm³, maximum ALE = 0.0327), and this cluster co-activated with two other clusters around the right cerebellum (peak 42, -56, -22, volume = 2560mm³, maximum ALE = 0.049) Lobule VI/Crus I and the left fusiform gyrus (BA47) (peak - 42, -46, -18, volume = 1616 mm³, maximum ALE = 0.046) and left cerebellum (peak - 42, -58, -20, volume = 1616mm³, maximum ALE = 0.033) Lobule VI/Crus I. While the left amygdala was associated with negative emotion (fear) (z = 3.047), the left fusiform gyrus/cerebellum Lobule VI/Crus I cluster was associated with language semantics (z = 3.724) and action observation (z = 3.077). These findings highlight the left amygdala as a region consistently hypo-activated in ASD and suggest the potential involvement of fusiform gyrus and cerebellum in social cognition in ASD. Future research should further elucidate if and how amygdala-fusiform/cerebellar connectivity relates to social and non-social cognition in adults with ASD.

Cerebellum and neurodevelopmental disorders: RORα is a unifying force

Errors of cerebellar development are increasingly acknowledged as risk factors for neuro-developmental disorders (NDDs), such as attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and schizophrenia. Evidence has been assembled from cerebellar abnormalities in autistic patients, as well as a range of genetic mutations identified in human patients that affect the cerebellar circuit, particularly Purkinje cells, and are associated with deficits of motor function, learning and social behavior; traits that are commonly associated with autism and schizophrenia. However, NDDs, such as ASD and schizophrenia, also include systemic abnormalities, e.g., chronic inflammation, abnormal circadian rhythms etc., which cannot be explained by lesions that only affect the cerebellum. Here we bring together phenotypic, circuit and structural evidence supporting the contribution of cerebellar dysfunction in NDDs and propose that the transcription factor Retinoid-related Orphan Receptor alpha (RORα) provides the missing link underlying both cerebellar and systemic abnormalities observed in NDDs. We present the role of RORα in cerebellar development and how the abnormalities that occur due to RORα deficiency could explain NDD symptoms. We then focus on how RORα is linked to NDDs, particularly ASD and schizophrenia, and how its diverse extra-cerebral actions can explain the systemic components of these diseases. Finally, we discuss how RORα-deficiency is likely a driving force for NDDs through its induction of cerebellar developmental defects, which in turn affect downstream targets, and its regulation of extracerebral systems, such as inflammation, circadian rhythms, and sexual dimorphism.

Role of cerebellum in sleep-dependent memory processes

The activities and role of the cerebellum in sleep have, until recently, been largely ignored by both the sleep and cerebellum fields. Human sleep studies often neglect the cerebellum because it is at a position in the skull that is inaccessible to EEG electrodes. Animal neurophysiology sleep studies have focussed mainly on the neocortex, thalamus and the hippocampus. However, recent neurophysiological studies have shown that not only does the cerebellum participate in the sleep cycle, but it may also be implicated in off-line memory consolidation. Here we review the literature on cerebellar activity during sleep and the role it plays in off-line motor learning, and introduce a hypothesis whereby the cerebellum continues to compute internal models during sleep that train the neocortex.

Do Children with Attention Deficit and Hyperactivity Disorder Present with Different Spatio-Temporal Gait Parameters? An Evaluation of the Relationship Between Gait and Gross Motor Skills

Objective

The aim of the current study was to compare the spatio-temporal parameters of gait and gross motor skills in children with attention deficit hyperactivity disorder-combined type with those of typically developing children and to search the effect of motor skills on gait parameters in children with attention deficit hyperactivity disorder-combined type.

Methods

A total of 50 children (n = 25 attention deficit hyperactivity disorder-combined type, n = 25 typically developing children) aged 5-12 years were included. Gross motor skills were evaluated using the Bruininks-Oseretsky Test Second Edition-Short Form. Spatio-temporal parameters of gait were assessed with a GAITRite^® computer-based system.

Results

In the subtests of Bruininks-Oseretsky Test Second Edition-Short Form (bilateral coordination (P < .001), balance (P = .013), running speed and agility (P = .003)), lower scores were obtained by the children with attention deficit hyperactivity disorder-combined type. The swing phase of gait was found to be longer in children with attention deficit hyperactivity disorder-combined type (P = .01).

Conclusion

The current study results show that gross motor skills are affected negatively and the swing phase is prolonged in children with attention deficit hyperactivity disorder-combined type. Upper limb coordination and balance were also seen to have an effect on the velocity, step, and stride length. It is important to include an objective gait assessment as well as gross motor skills in the comprehensive clinical evaluation of children with attention deficit hyperactivity disorder-combined type.