Growth and refinement of excitatory synapses in the human auditory cortex

Codon Usage Bias: A Potential Factor Affecting VGLUT Developmental Expression and Protein Evolution

More and more attention has been paid to the role of synonymous substitution in evolution, in which codon usage preference can affect gene expression distribution and protein structure and function. Vesicular glutamate transporter (VGLUT) consists of three isoforms, among which VGLUT3 is significantly different from other VGLUTs in functional importance, expression level, and distribution range, whose reason is still unclear. This study sought to analyze the role of codon preference in VGLUT differentiation. To conduct an evolutionary analysis of the three VGLUTs, this paper uses bioinformatics research methods to analyze the coding sequences of the three VGLUTs in different species and compare the codon usage patterns. Furthermore, the differences among the three VGLUTs were analyzed by combining functional importance, expression level, distribution range, gene structure, protein relationship network, expression at specific developmental stages, and phylogenetic tree, and the influence of codon usage pattern was explored. The results showed that the VGLUT with greater codon preference had less functional importance, lower expression levels, more peripheral distribution away from the CNS, smaller exon density of gene, less conserved and farther away from the CDS region miRNA regulatory sites, simpler and less tight protein interaction networks, delayed developmental expression, and more distant evolutionary relationships. Codon usage preference is a potential factor affecting VGLUT developmental expression and protein evolution.

Duplicated Heschl's gyrus associations with phonological decoding

The reason(s) for why a complete duplication of the left hemisphere Heschl's gyrus (HG) has been observed in people with reading disability are unclear. This study was designed to replicate and advance understanding of the HG and phonological decoding association, as well as test competing hypotheses that this HG duplication association is specifically localized to the HG or could be due to co-occurring atypical development of other brain regions that support reading and language development. Participants were selected on the basis of having a duplicated left hemisphere HG (N = 96) or a single HG (N = 96) and matched according to age, sex, and research site in this multi-site study. Duplicated and single HG morphology specific templates were created to determine the extent to which HG sizes were related to phonological decoding within each HG morphology group. The duplicated HG group had significantly lower phonological decoding (F = 4.48, p = 0.04) but not verbal IQ (F = 1.39, p = 0.41) compared to the single HG group. In addition, larger HG were significantly associated with lower phonological decoding in the duplicated HG group, with effects driven by the size of the lateral HG after controlling for age, sex, research site, and handedness (ps < 0.05). Brain regions that exhibited structural covariance with HG did not clearly explain the HG and phonological decoding associations. Together, the results suggest that presence of a duplicated HG indicates some risk for lower phonological decoding ability compared to verbal IQ, but the reason(s) for this association remain unclear.

Cortical auditory evoked potentials (P1 latency) in children with cochlear implants in relation to clinical language tests

Objective - To study the correlation between P1 latency and the results of clinical language tests (Reynell III and TROG-2), the latter were used as they are recommended for follow-up assessments of children with cochlear implants (Cis) by the Swedish National Quality Register for children with hearing impairment.Design - A clinical cohort study.Study sample - Cross-sectional and consecutive sampling of 49 children with CIs coming for clinical follow-up assessment from March 2017 - December 2019.Results - For all children tested, there was a significant negative correlation (Spearman's rho= -0.403, p = 0.011) between hearing age and P1 latency. A significant correlation between P1 latency and the Reynell III result (Spearman's rho =  -0.810, p = 0.015) was found. In the TROG-2 group, there was no significant correlation between their P1 latency and their language test results (Spearman's rho -0.239, p = 0.196).Conclusion - This method seems to be feasible and easily accepted. The study was conducted in a heterogeneous group of children that we meet daily in our clinic. The results indicated that P1 latency has a negative correlation with language development among our youngest patients fitted with CIs and might be a clinical tool to assess the maturation of central auditory pathways.

Structural Covariance of the Duplicated Heschl's Gyrus: A Sulcal/Gyral Template Morphology Approach

Heschl's gyrus (HG) can occur as a single gyrus or with a completely duplicated posterior HG that has been related to a variety of abilities and disorders. Voxel-based studies typically involve the normalization of these qualitatively different HG types, thus making it difficult to evaluate the contribution of sulcal/gyral variability to voxel-based effects and perhaps obscuring some effects. To examine the structural covariance of single and duplicated HG, templates were created for the left single and duplicated HG. Structural covariance analysis with a Jacobian measure of volumetric displacement demonstrated consistent spatial covariance with homologous structure in the right hemisphere across qualitatively different HG morphology. These results suggest that HG duplication is aptly named with respect to cortical structure variation and demonstrate a multi-template approach for studying qualitatively unique brain function and structure linked to perceptual and cognitive functions.

HIGHLIGHTS

Qualitatively unique sulcal/gyral features can affect voxel-based analyses.Heschl's gyrus is highly variable across people.Morphology-specific templates were created to study Heschl's gyrus structural covariance.Single and duplicated Heschl's gyrus exhibited a similar pattern of covariance.

The neural correlates of hedonic and eudaimonic happiness: An fMRI study

The current study investigated the neural correlates of both hedonic and eudaimonic happiness. Seventeen students underwent fMRI while cued with written sentences describing three classes of life events: Hedonic events (HE), eudaimonic events (EE) and neutral events (NE). We asked participants to imagine and empathize with all these event types. Results showed that, compared to NE, both HE and EE activated a network involving frontal, temporal and parietal regions, as well as subcortical structures. However, in the HE/EE comparison, HE showed enhanced activity in frontal medial/middle regions and anterior cingulate cortex; by contrast, EE showed increased activity in the right precentral gyrus. Findings suggest that hedonic and eudaimonic happiness activate similar neural correlates. However, both kinds of happiness are also associated with distinctive brain areas serving distinctive functions.