acase@tulane.edu

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acase@tulane.edu

Microstructural and electrophysiological properties of neural tissue are substantially influenced by the immediate extracellular environment wtihin the nervous system. These properties are also arguably the most clinically-relevant and sensitive measures of nerve health. However, the neurological architecture, physiology, and surrounding extracellular matrix are hard to mimic in vitro, and an increasing need for culture platforms that reproduce these complex features has led to the development of 3D cultures and microscale engineered tissues for functional assays. Using a dual hydrogel construct and explants from rat embryonic dorsal root ganglia, we present an in vitro platform for culturing spatially-controlled 3D neurite growth that supports both intracellular and extracellular electrophysiological recordings. Specifically, these 3D neural cultures in hydrogel exhibit both structural and functional characteristics that closely mimic those of sensory peripheral nervous tissue found in vivo. However, the 3D hydrogel constructs allow incorporation of other cell types, fabrication in any geometry, and simultaneous electrical stimulation and probing, providing a viable assay for systematic culture, manipulation, and testing of biomimetic neural growth in any mechanistic study necessitating physiologically-relevant readouts. / acase@tulane.edu

acase@tulane.edu

This study investigated potential ways in which student-reported stress and support levels, represented by the Ecomap stress-support index (SSI), could inform school-based universal screening efforts. Participants included 260 students in grades K to 3 attending an urban elementary charter school in New Orleans, Louisiana, during the academic year of 2011-2012, for whom specific data relevant to the study's variables were available in school records. Child self-report of stress and support (SSI), measured by the Ecomap, was hypothesized to enhance the prediction of school academic and behavioral outcomes, measured by achievement and behavior reports, beyond teacher report of social emotional functioning and school functioning, as reported on the Behavioral Assessment System for Children: Behavioral and Emotional Screening System (BESS) 1. Step-wise regression analyses were conducted. Results indicated that the BESS and Ecomap SSI together predicted variance in behavior reports and academic scores; however, the SSI did not account for significant additional variance. The Ecomap SSI also was hypothesized to explain variances in student self-reports of internalizing difficulties, whereas teacher reports of student functioning on the (BESS) were hypothesized to explain variances in reports of externalizing difficulties. Multiple regression analyses were used to explore this relationship. The Ecomap SSI was found to predict Attention Difficulties reported by students on the Behavioral Assessment System for Children: Self-Report Protocol C (BASC-2, SRP), with higher reports of stress corresponding to higher reports of attention problems. Findings indicate that data on student stress can be useful in the mental health screening process and provide important information that could inform intervention. / acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

Atypical sensory reactivity to visual and/or auditory stimuli is prevalent among individuals with autism spectrum disorders (ASD). Data from cognitive neuroscience research suggests that changes in attention can alter sensory processing at several levels of analysis, and thus could be contributing to changes in sensory reactivity. Furthermore, attentional pathways are modulated by the individual difference variable of working memory capacity (WMC). This study examined the relationship between sensory reactivity, individual difference, and auditory attention in ASD by using electroencephalography technique. Participants (n=25, 12 with ASD and 13 age- and IQ-matched controls) completed a sensory profile, complex operation span task for working memory capacity (WMC), and performed a modified 3-stimulus (target, non-target, and distractor) oddball task under varying perceptual load (high or low). Event-related potential (ERP) analysis assessed early sensory processing (P50, ~50ms latency; N100, ~100ms latency), cognitive control (N200, ~200ms latency), and attentional processing (P3a and P3b, ~300ms latency). Behavioral data demonstrates participants with ASD and neurotypical performed similarly on WMC and auditory target detection, but diverged in sensory profiles. In target processing under high perceptual load did not enhance P3b latency in those with ASD suggesting increased perceptual capacity compared to neurotypicals. No neurophysiological difference between groups in target data suggests intact top-down control in people with and without ASD. Early and late orienting ERPs (P50, N100, P3a) in non-target processing were unaffected by perceptual load. Robust differences in distractor processing were observed between groups in both early (N100) and late (N200) neural correlates of auditory attention. N100 responses in participants with ASD were strongly attenuated by increasing perceptual load compared to neurotypical controls. Decreased distractor interference at high loads in participants with ASD contrasted attenuation of enhanced late, perceptual processes indexed by the N200 in neurotypical controls. Increased perceptual capacity and decreased distractor processing suggest enhanced bottom-up attention in participant with ASD and has a direct relationship to atypical sensory reactivity in ASD. Collectively, data describes intact top-down control, behaviorally and neurophysiologically, while demonstrating benefits of atypical sensory reactivity on bottom-up attention in people with ASD. / acase@tulane.edu