Social Brain Network of Children with Autism Spectrum Disorder: Characterization of Functional Connectivity and Potential Association with Stereotyped Behavior

The Impact of Microglia on Neurodevelopment and Brain Function in Autism

Microglia, as one of the main types of glial cells in the central nervous system (CNS), are widely distributed throughout the brain and spinal cord. The normal number and function of microglia are very important for maintaining homeostasis in the CNS. In recent years, scientists have paid widespread attention to the role of microglia in the CNS. Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder, and patients with ASD have severe deficits in behavior, social skills, and communication. Most previous studies on ASD have focused on neuronal pathological changes, such as increased cell proliferation, accelerated neuronal differentiation, impaired synaptic development, and reduced neuronal spontaneous and synchronous activity. Currently, more and more research has found that microglia, as immune cells, can promote neurogenesis and synaptic pruning to maintain CNS homeostasis. They can usually reduce unnecessary synaptic connections early in life. Some researchers have proposed that many pathological phenotypes of ASD may be caused by microglial abnormalities. Based on this, we summarize recent research on microglia in ASD, focusing on the function of microglia and neurodevelopmental abnormalities. We aim to clarify the essential factors influenced by microglia in ASD and explore the possibility of microglia-related pathways as potential research targets for ASD.

Vasotocin receptor gene genotypes moderate the relationship between cortical thickness and sensory processing

Sensory processing is the process by which the central nervous system gathers, interprets, and regulates sensory stimuli in response to environmental cues. However, our understanding of the genetic factors and neuroanatomical correlations that influence sensory processing is limited. The vasotocin system modulates sensory input responsiveness, making it a potential candidate for further investigation. Additionally, human neuroimaging studies have demonstrated that the ability to modulate sensory stimuli is related to neuroanatomical features such as cortical thickness. Therefore, this study aimed to examine the relationship between functional polymorphisms in vasotocin receptor (VTR) genes, sensory profiles, and neuroanatomical correlations. We used structural magnetic resonance imaging (MRI) and the Adolescent/Adult Sensory Profile (AASP) questionnaire in 98 healthy adult participants to assess sensory processing and identified seven single nucleotide polymorphisms. We found that A-allele carriers of rs1042615 in VTR had higher scores for "sensory sensitivity" and "sensation avoiding". Moreover, higher scores for three AASP subscales were associated with decreased cortical thickness in various regions, including the right precentral, paracentral, and fusiform gyri, as well as bilateral inferior temporal gyri. This study sheds light on the potential role of genetic variations in the VTR in modulating sensory processing and correlation with cortical thickness which has future implications for better understanding sensory abnormalities in neurodevelopmental disorders.

High definition transcranial direct current stimulation of the Cz improves social dysfunction in children with autism spectrum disorder: A randomized, sham, controlled study

The purpose of this study was to determine the effect of the Cz of high-definition 5-channel tDCS (HD-tDCS) on social function in 4-12 years-old children with autism spectrum disorder (ASD). This study was a randomized, double-blind, pseudo-controlled trial in which 45 ASD children were recruited and divided into three groups with sex, age, and rehabilitation treatment as control variables. Each group of 15 children with ASD was randomly administered active HD-tDCS with the Cz as the central anode, active HD-tDCS with the left dorsolateral prefrontal cortex (F3) as the central anode, and sham HD-tDCS with the Cz as the central anode with 14 daily sessions in 3 weeks. The Social Responsiveness Scale Chinese Version (SRS-Chinese Version) was compared 1 week after stimulation with values recorded 1 week prior to stimulation. At the end of treatment, both the anodal Cz and anodal left DLFPC tDCS decreased the measures of SRS-Chinese Version. The total score of SRS-Chinese Version decreased by 13.08%, social cognition decreased by 18.33%, and social communication decreased by 10.79%, which were significantly improved over the Cz central anode active stimulation group, especially in children with young age, and middle and low function. There was no significant change in the total score and subscale score of SRS-Chinese Version over the Cz central anode sham stimulation group. In the F3 central anode active stimulation group, the total score of SRS-Chinese Version decreased by 13%, autistic behavior decreased by 19.39%, and social communication decreased by 14.39%, which were all significantly improved. However, there was no significant difference in effect between the Cz and left DLPFC stimulation conditions. HD-tDCS of the Cz central anode may be an effective treatment for social dysfunction in children with ASD.

Event-Related Desynchronization of MEG Alpha-Band Oscillations during Simultaneous Presentation of Audio and Visual Stimuli in Children with Autism Spectrum Disorder

Alpha-band (8-12 Hz) event-related desynchronization (ERD) or a decrease in alpha power in electro- and magnetoencephalography (EEG and MEG) reflects the involvement of a neural tissue in information processing. It is known that most children with autism spectrum disorder (ASD) have difficulties in information processing, and, thus, investigation of alpha oscillations is of particular interest in this population. Previous studies have demonstrated alterations in this neural activity in individuals with ASD; however, little is known about alpha ERD during simultaneous presentation of auditory and visual stimuli in children with and without ASD. As alpha oscillations are intimately related to attention, and attention deficit is one of the common co-occurring conditions of ASD, we predict that children with ASD can have altered alpha ERD in one of the sensory domains. In the present study, we used MEG to investigate alpha ERD in groups of 20 children with ASD and 20 age-matched typically developing controls. Simple amplitude-modulated tones were presented together with a fixation cross appearing on the screen. The results showed that children with ASD had a bilateral reduction in alpha-band ERD in the auditory but not visual cortex. Moreover, alterations in the auditory cortex were associated with a higher presence of autistic traits measured in behavioral assessment.