Mapping gene expression in social anxiety reveals the main brain structures involved in this disorder

Spatiotemporal expression patterns of anxiety disorder-associated genes

Anxiety disorders (ADs) are the most common form of mental disorder that affects millions of individuals worldwide. Although physiological studies have revealed the neural circuits related to AD symptoms, how AD-associated genes are spatiotemporally expressed in the human brain still remains unclear. In this study, we integrated genome-wide association studies of four human AD subtypes-generalized anxiety disorder, social anxiety disorder, panic disorder, and obsessive-compulsive disorder-with spatial gene expression patterns. Our investigation uncovered a novel division among AD-associated genes, marked by significant and distinct expression enrichments in the cerebral nuclei, limbic, and midbrain regions. Each gene cluster was associated with specific anxiety-related behaviors, signaling pathways, region-specific gene networks, and cell types. Notably, we observed a significant negative correlation in the temporal expression patterns of these gene clusters during various developmental stages. Moreover, the specific brain regions enriched in each gene group aligned with neural circuits previously associated with negative decision-making and anxious temperament. These results suggest that the two distinct gene clusters may underlie separate neural systems involved in anxiety. As a result, our findings bridge the gap between genes and neural circuitry, shedding light on the mechanisms underlying AD-associated behaviors.

The Prevalence and Sociodemographic Correlates of Social Anxiety Disorder: A Focused National Survey

Background

Social Anxiety Disorder (SAD) is among the most common anxiety disorders worldwide with data largely emerging from the Euro-American and Pacific Rim populations. In contrast, there is a dearth of studies among the populations of Arabian Gulf countries including Oman. This study has two interrelated aims: (i) to explore the prevalence of SAD among Omani adults, and (ii) to tease out the links between socio-demographic factors and SAD in Oman.

Methods

A cross-sectional study via an online survey was conducted among 1019 adult Omani nationals residing in Oman. The presence of SAD was assessed using the Arabic version of the Liebowitz Social Anxiety Scale (LSAS).

Results

Nearly half the participants (45.9%, n = 468) exhibited “caseness” for SAD as defined by LSAS. In the multivariate logistic analysis, participants below 40 years of age were 1.6 times (OR = 1.568, p = .026) more likely to have caseness for SAD than those who were 40 and older. Women were 1.3 times (OR = 1.348, p = .038) more likely to exhibit caseness for SAD than men. Participants who had secondary or undergraduate education were respectively 1.5 times (OR = 1.45, p = .014) and 2.5 times (OR = 2.509, p < .001) to have caseness for SAD than those who were graduates.

Conclusion

The present data suggest that 45.9% of the participants reached the cut-off for caseness in LSAS, which is high compared to reports from other populations. The present accrued frequency is discussed within the context of the accrued response rate, socio-cultural factors as well as the tendency for self-reported measures to “produce” spurious results is also highlighted which, in turn, calls for studies that adopt more inclusive survey methods.

Genome-enabled discovery of evolutionary divergence in brains and behavior

Lake Malawi cichlid fishes exhibit extensive divergence in form and function built from a relatively small number of genetic changes. We compared the genomes of rock- and sand-dwelling species and asked which genetic variants differed among the groups. We found that 96% of differentiated variants reside in non-coding sequence but these non-coding diverged variants are evolutionarily conserved. Genome regions near differentiated variants are enriched for craniofacial, neural and behavioral categories. Following leads from genome sequence, we used rock- vs. sand-species and their hybrids to (i) delineate the push-pull roles of BMP signaling and irx1b in the specification of forebrain territories during gastrulation and (ii) reveal striking context-dependent brain gene expression during adult social behavior. Our results demonstrate how divergent genome sequences can predict differences in key evolutionary traits. We highlight the promise of evolutionary reverse genetics-the inference of phenotypic divergence from unbiased genome sequencing and then empirical validation in natural populations.