Autism Spectrum Disorder

The perception and interpretation of faces provides individuals with a wealth of knowledge that enables them to navigate their social environments more successfully. Prior research has hypothesized that the decreased facial expression recognition (FER) abilities observed in autism spectrum disorder (ASD) may be better explained by comorbid alexithymia, the alexithymia hypothesis. The present study sought to further examine the alexithymia hypothesis by collecting data from 59 participants and examining FER performance and eye movement patterns for ASD and neurotypical (NT) individuals while controlling for alexithymia severity. Eye movement-related differences and similarities were examined via eye tracking in conjunction with statistical and machine-learning-based pattern classification analysis. In multiple different classifying conditions, where the classifier was fed 1,718 scanpath images (either at spatial, spatial-temporal, or spatial temporal-ordinal levels) for high-alexithymic ASD, high-alexithymicvi NT, low-alexithymic ASD, and low-alexithymic NT, we could accurately decode significantly above chance level. Additionally, in the cross-decoding analysis where the classifier was fed 1,718 scanpath images for high- and low alexithymic ASD individuals and tested on high- and low-alexithymic NT individuals, results showed that classification accuracy was significantly above chance level when using spatial images of eye movement patterns. Regarding FER performance results, we found that ASD and NT groups performed similarly, but at lower intensities of expressions, ASD individuals performed significantly worse than NT individuals. Together, these findings suggest that there may be eye-movement related differences between ASD and NT individuals, which may interact with alexithymia traits.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that effects about 1 in 44 children and has steadily increased in prevalence over the last decades. ASD is characterized by the diagnostic criteria of a persistent deficit in social communication and interaction and restricted or repetitive behaviors. The amygdala plays an essential role in regulating these behaviors and has continuously been shown to be affected in patients with ASD. As the amygdala is connected throughout the brain with cortical and subcortical areas, it is crucial to understand potential circuit impairments that contribute to the development and progression of behavioral characteristics. In this study, we investigated the role of ASD-associated TBR1 haploinsufficiency on morphological and functional amygdala connectivity. While we don’t see differences in inputs to the basal amygdala (BA), we demonstrated a difference in the BA to prefrontal cortex (PFC) pathway. Interestingly, we show a specific innervation difference of layer 5 neurons in the infralimbic (IL) but not prelimbic (PL) nuclei in the PFC. In accordance with the overall reduced density of BA axons in the IL, we show a decreased density of excitatory synapses. To investigate possible functional consequences of this projection deficit, we characterized pre-and postsynaptic functions of BA-PFC synapses. TBR1 haploinsufficiency impairs the postsynaptic function of BA-PL layer 2/3 and IL layer 5 synapses. BA-PL layer 2/3 synapses show an increased AMPA/NMDA receptor ratio, while this is not observed in BA-IL layer 5 synapses. However, TBR1 haploinsufficiency increases the AMPA and NMDA receptor-mediated currents at these synapses, further highlighting that BA-PL and BA-IL synapses are different and that partial loss of TBR1 affects circuits differently. This novel characterization of the consequences of a TBR1 haploinsufficiency on BA connectivity contributes to the critical understanding of this ASD-associated gene and its detrimental effects that contribute to the underlying behavioral phenotype.

This study is an informative, phenomenological inquiry, investigating the lived experiences of Black parents and guardians through the autism spectrum disorder (ASD) identification process. Through semi-structured oral interviews, parent questionnaires, and parent journaling, the researcher identified participants’ lived experiences. Data were collected, participant interview responses, parent questionnaires, and parent journal entries were analyzed, a list of significant statements was categorized and grouped into meaning units, and textural, structural, and composite descriptions of the phenomena were identified (Moustakas, 1994). Categories and themes, as well as perceived facilitators and barriers were identified. Review of the literature indicates little research has been conducted in investigating the lived experiences of Black parents through the autism identification process. Recommendations from the study are provided to inform parental training needs and supports, to assist in the facilitation of effective identification, as well as necessary recommendations for how educators and health care professionals can better support Black parents through the ASD identification process.

Autism spectrum disorder (ASD) is a complex disorder with large individual variability, where every case has differences in the type and severity of symptoms. Despite the recent increase in diagnoses, scientists have advanced considerably less in their understanding of the mechanisms of ASD because few individual genes that are implicated in ASD are mutated in much more than 1% of patients. One proposed mechanism is that the dysfunction of GABAergic interneurons may play a role in the development and progression of the disorder by interrupting the excitatory and inhibitory balance of neural networks. In our research, we elucidate the role of one class of interneurons in ASD by knocking out a high-risk gene (phosphatase and tensin homologue on chromosome ten, or PTEN) selectively in somatostatinexpressing (SOM+) interneurons. Since many symptoms of autism spectrum disorder present themselves as social anxieties, we test our mouse model in a variety of settings to observe social interaction and social preference, anxiety-like behavior, and repetitive stereotyped behavior. We found that in the SOM+ conditional knockout of PTEN, mice had elevated levels of anxiety and fear recall, suggesting a potential disruption of amygdala function. We then investigated potential dysfunction at the cellular and circuit levels using confocal microscopy, electrophysiology, and 2P local circuit mapping. We found that SOM+ cells lacking PTEN were overgrown morphologically, with larger cell bodies and larger, more complex dendritic arbors. Additionally, SOM+ cells in the central amygdala (CeA) lacking PTEN had elevated levels of excitatory drive from the basolateral amygdala (BLA) as well as a drastic disruption of lateral inhibition within the CeA, seen by decreased connection probability and reduced inhibitory post synaptic currents. Given what is known about central amygdala circuitry, these deficits in CeA SOM+ neuron activity conceivably underlie the fear and anxiety-related phenotype observed in mice with a conditional SOM+ PTEN knockout.

The purpose of this quasi-experimental study was to measure the impacts of attendance in a three-month series of social groups on the self-perceptions of autism spectrum disorder (ASD) symptomology, social skills, and loneliness for adults with ASD. The study also measured the impacts of attendance in a three-month series of social groups on perceptions of ASD symptomology and social skills for the caregivers of adults with ASD. This study utilized a convenience sample of adults that were existing members of Florida Atlantic University’s Center for Autism and Related Disabilities (FAU CARD) Adult Social Group and an identified caregiver. Data was collected over a period of four months. This was the first study to examine the impacts of participation in a semi-structured social group on perceptions of ASD symptomology, social skills, and loneliness for adults with ASD, as prior studies had focused on more structured, clinical interventions. Variance in perceptions over the three-month series was analyzed using a repeated measures MANOVA. Significant differences were reported over the three month period on both adult self-perception and caregiver perception for ASD symptomology, social skills, and loneliness (N=76).

The causes of autism spectrum disorder (ASD) are not all known, but it is suspected that the serotonin transporter (SERT) plays an important role for some subjects with ASD. Mutations in the SLC6A4 gene, that encodes SERT, including the Ala56 mutation (Gly56Ala), have been found in some autism patients. This mutation makes the transporter more active and reduces the probability of serotonergic neurotransmission in the brain, which is linked to behavioral changes that are associated with core domain deficits of ASD 1.
Depression also has been linked to decreases in the availability of serotonin (5-hydroxytryptamine; 5-HT) in the central nervous system (CNS), and is associated with reduced hippocampal neurogenesis. Selective serotonin reuptake inhibitors (SSRIs), drugs used to block SERTs, are used to treat depression and/or anxiety by inhibiting SERT to increase synaptic 5-HT levels.