Background Behavioral symptoms in individuals with autism spectrum disorder (ASD) have been attributed to abnormal neuronal connectivity, but the molecular bases of these behavioral and brain phenotypes are largely unknown. Human genetic studies have implicated Protocadherin 10 (PCDH10), a member of the δ2 subfamily of non-clustered protocadherin genes, in ASD. PCDH10 expression is enriched in the basolateral amygdala, a brain region implicated in the social deficits of ASD. Previous reports indicate that Pcdh10 plays a role in axon outgrowth and glutamatergic synapse elimination, but its roles in social behaviors and amygdala neuronal connectivity are unknown. We hypothesized that haploinsufficiency of Pcdh10 would reduce social approach behavior and alter the structure and function of amygdala circuits. Methods Mice lacking one copy of Pcdh10 (Pcdh10+/−) and wildtype littermates (WT) were assessed for social approach and other behaviors. The lateral/basolateral amygdala was assessed for dendritic spine number and morphology, and amygdala circuit function was studied using voltage sensitive dye imaging. Expression of Pcdh10 and N-methyl-D-aspartate receptor (NMDAR) subunits was assessed in post-synaptic density fractions of amygdala. Results Male Pcdh10+/− mice have reduced social approach behavior, as well as impaired gamma synchronization, abnormal spine morphology, and reduced levels of NMDAR subunits in amygdala. Social approach deficits in Pcdh10+/− males were rescued with acute treatment with the NMDAR partial agonist d-cycloserine. Conclusions Our studies reveal that male Pcdh10+/− mice have synaptic and behavioral deficits, and establish Pcdh10+/− mice as a novel genetic model for investigating neural circuitry and behavioral changes relevant to ASD.

The goal of this study was to measure behaviors that contribute to social functioning difficulties in adults with ASD, with the ultimate goal of guiding treatment development. We found that motivation to interact with others was significantly related to social anxiety and social skill. Our results suggest that motivation may be important to target in treatment, and that treatments should be tailored to the areas most in need of improvement in each individual.

Purpose of review:There is a perceived shortage of evidence-based treatment programs for adults on the autism spectrum. This article reviews the recent research literature on psychosocial / behavioral interventions targeting social functioning in autistic adults without intellectual disability. Recent findings:We identified only 41 peer-reviewed studies published from 1980 through 2017 that tested intervention programs focused on one or more of the behavioral components of social functioning (i.e. social motivation, social anxiety, social cognition, and social skills) in more than one adult with autism spectrum disorder (ASD). The studies demonstrated substantial variability in treatment objectives, intervention procedures, assessment methods, and methodologic quality. Summary:The results indicate a strong need for additional research to develop and rigorously test interventions for autistic adults that target the many behavioral components of social functioning and that include procedures to promote generalization of knowledge and skills to community settings.

Background Learning through social observation (i.e., watching other people interact) lays the foundation for later social skills and social cognition. However, social situations are often complex, and humans are only capable of attending to one aspect of a scene at a time. How do people choose where to allocate their visual resources when viewing complex social scenarios? For typically developing (TD) individuals, faces are often given priority. Depending upon context, however, it may be more useful to attend to other aspects of the environment, such as hands, tools, or background objects. Previous studies reported reduced face looking in individuals with autism spectrum disorder (ASD), but modulation of visual attention in response to contextual differences (e.g., according to social richness , or the presence/absence of communicative behaviors between two people) has only briefly been explored. In this study, we used eye-tracking technology to test the extent to which ASD adults and TD adults use social context to guide their gaze behavior. Methods Fifty-five adults participated (28 with ASD). The location and duration of participants’ gaze were recorded while they watched a series of naturalistic social videos. Half of the videos depicted two people engaging in non-verbal communication ( rich social scenes) while playing with toys. The other half depicted two people playing with toys separately, not interacting with each other ( lean social scenes). Results ASD and TD adults both increased their attention to faces in communicative contexts ( rich social scenes) as compared to non-communicative contexts ( lean social scenes). However, TD adults increased their attention to faces significantly more when watching two people communicate than did ASD adults, who increased their attention to a lesser degree. Further analysis revealed that ASD adults persisted in looking at hands and toys, even when observing two people communicate in a rich social scene. Conclusions Diminished gaze to faces when observing two people communicating may lead to fewer opportunities for social learning and subsequent reductions in social knowledge. Naturalistic measures of contextual modulation could help identify areas of need for individuals learning about the social world and could become treatment targets to improve everyday social learning.