Effect of Propranolol on Functional Connectivity in Autism Spectrum Disorder—A Pilot Study

A decrease in interaction between brain regions is observed in individuals with autism spectrum disorder (ASD), which is believed to be related to restricted neural network access in ASD. Propranolol, a beta-adrenergic antagonist, has revealed benefit during performance of tasks involving flexibility of access to networks, a benefit also seen in ASD. Our goal was to determine the effect of propranolol on functional connectivity in ASD during a verbal decision making task as compared to nadolol, thereby accounting for the potential spurious fMRI effects due to peripheral hemodynamic effects of propranolol. Ten ASD subjects underwent fMRI scans after administration of placebo, propranolol or nadolol, while performing a phonological decision making task. Comparison of functional connectivity between pre-defined ROI-pairs revealed a significant increase with propranolol compared to nadolol, suggesting a potential imaging marker for the cognitive effects of propranolol in ASD

Intrinsic Stability of Temporally Shifted Spike-Timing Dependent Plasticity

Spike-timing dependent plasticity (STDP), a widespread synaptic modification mechanism, is sensitive to correlations between presynaptic spike trains and it generates competition among synapses. However, STDP has an inherent instability because strong synapses are more likely to be strengthened than weak ones, causing them to grow in strength until some biophysical limit is reached. Through simulations and analytic calculations, we show that a small temporal shift in the STDP window that causes synchronous, or nearly synchronous, pre- and postsynaptic action potentials to induce long-term depression can stabilize synaptic strengths. Shifted STDP also stabilizes the postsynaptic firing rate and can implement both Hebbian and anti-Hebbian forms of competitive synaptic plasticity. Interestingly, the overall level of inhibition determines whether plasticity is Hebbian or anti-Hebbian. Even a random symmetric jitter of a few milliseconds in the STDP window can stabilize synaptic strengths while retaining these features. The same results hold for a shifted version of the more recent “triplet” model of STDP. Our results indicate that the detailed shape of the STDP window function near the transition from depression to potentiation is of the utmost importance in determining the consequences of STDP, suggesting that this region warrants further experimental study

The Psychosocial Impact of Cleft in a Western Australian Cohort Across 3 Age Groups

BACKGROUND:: Management of a cleft of the lip and/or palate (CL/P) involves a multidisciplinary team approach lasting from birth to potentially postskeletal maturity. This condition is complex, with both medical and psychosocial implications that may place individuals with a cleft at higher risk of developing psychosocial problems. METHODOLOGY:: A self-administered questionnaire was completed by a sample from the Western Australian cleft population comprising 3 age groups: child (n = 100), adolescent (n = 101), and adult (n = 158). RESULTS:: Public speaking, being photographed, special relationships, and participation in school were identified as the areas most impacted by having a cleft. Hearing and speech were reported to have a higher importance than facial and dental appearance. Participants rated support given to them by their parents as the most important, with high ratings for treatment providers. For teasing, the impact of cleft was significantly higher among participants with cleft lip and palate for both the adolescent and adult age groups. There was little significant difference by gender across the variables, which suggests that males are just as likely to require support as females. CONCLUSION:: The impact of a cleft across multiple psychosocial domains needs to be recognized and addressed as part of craniofacial team care across age groups