Cognitive Development and Brain Gray Matter Susceptibility to Prenatal Adversities: Moderation by the Prefrontal Cortex Brain-Derived Neurotrophic Factor Gene Co-expression Network

Background: Previous studies focused on the relationship between prenatal conditions and neurodevelopmental outcomes later in life, but few have explored the interplay between gene co-expression networks and prenatal adversity conditions on cognitive development trajectories and gray matter density.Methods: We analyzed the moderation effects of an expression polygenic score (ePRS) for the Brain-derived Neurotrophic Factor gene network (BDNF ePRS) on the association between prenatal adversity and child cognitive development. A score based on genes co-expressed with the prefrontal cortex (PFC) BDNF was created, using the effect size of the association between the individual single nucleotide polymorphisms (SNP) and the BDNF expression in the PFC. Cognitive development trajectories of 157 young children from the Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) cohort were assessed longitudinally in 4-time points (6, 12, 18, and 36 months) using the Bayley-II mental scales.Results: Linear mixed-effects modeling indicated that BDNF ePRS moderates the effects of prenatal adversity on cognitive growth. In children with high BDNF ePRS, higher prenatal adversity was associated with slower cognitive development in comparison with those exposed to lower prenatal adversity. Parallel-Independent Component Analysis (pICA) suggested that associations of expression-based SNPs and gray matter density significantly differed between low and high prenatal adversity groups. The brain IC included areas involved in visual association processes (Brodmann area 19 and 18), reallocation of attention, and integration of information across the supramodal cortex (Brodmann area 10).Conclusion: Cognitive development trajectories and brain gray matter seem to be influenced by the interplay of prenatal environmental conditions and the expression of an important BDNF gene network that guides the growth and plasticity of neurons and synapses.

Anosognosia in Amnestic Mild Cognitive Impairment Is Related to Diminished Hippocampal Volume Comparable to Alzheimer’s Disease Dementia: Preliminary MRI Findings

Although the presence of anosognosia in amnestic mild cognitive impairment (aMCI) may be predictive of conversion to Alzheimer’s disease (AD), little is known about its neural correlates in AD and aMCI. Four different groups were compared using volumetric and diffusion magnetic resonance imaging metrics in regions of interest (hippocampus and cingulum cortex gray matter, cingulum bundle white matter): aMCI subjects with anosognosia (n = 6), aMCI subjects without anosognosia (n = 12), AD subjects with anosognosia (n = 6), and AD subjects without anosognosia (n = 9). aMCI subjects with anosognosia displayed a significantly lower gray matter density (GMD) in the bilateral hippocampus than aMCI subjects without anosognosia, which was accounted for by bilateral hippocampal differences. Furthermore, we identified that the mean hippocampal gray matter density of aMCI subjects with anosognosia was not statistically different than that of AD subjects. The groups of aMCI and AD subjects with anosognosia also displayed a lower GMD in the bilateral cingulum cortex compared to subjects without anosognosia, but these differences were not statistically significant. No statistically significant differences were found in the fractional anisotropy or mean diffusivity of the hippocampus or cingulum between subjects with and without anosognosia in aMCI or AD groups. While these findings are derived from a small population of subjects and are in need of replication, they suggest that anosognosia in aMCI might be a useful clinical marker to suspect brain changes associated with AD neuropathology.

Linking temporal-parietal junction to internet addiction tendency: Moderating effect of critical thinking

Backgrounds and aims Internet addiction (IA) is a common internet-related addictive behavior. An enormous amount of previous research on IA disorders (IADs) have paid attention to the neural basis of abnormalities, while few studies have elucidated the neural distinctions of IA tendency in general population. Methods The current study examined the neural basis of IA tendency combining with voxel-based morphometry (VBM) from the average student body (N = 244). Results As the results presented, the gray matter density (GMD) of the left temporal-parietal junction (TPJ) was positively correlated with Internet Addiction Test (IAT) score. Further analysis revealed that critical thinking moderated the path between GMD in the TPJ and IA tendency. Specifically, the correlation between GMD in the TPJ and IA tendency was weaker for those with a higher critical thinking disposition. Discussion and conclusion Higher critical thinking show a hindering effect in susceptibility to IA based on the neural basis of temporal-parietal junction differences.

Neuroanatomical Correlates of Macrolinguistic Aspects in Narrative Discourse in Unilateral Left and Right Hemisphere Stroke: A Voxel-Based Morphometry Study

Background A growing body of literature has demonstrated the importance of discourse assessment in patients who suffered from brain injury, both in the left and right hemispheres, as discourse represents a key component of functional communication. However, little is known about the relationship between gray matter density and macrolinguistic processing. Purpose This study aimed to investigate this relationship in a group of participants with middle–low to low socioeconomic status. Method Twenty adults with unilateral left hemisphere ( n = 10) or right hemisphere ( n = 10) chronic ischemic stroke and 10 matched (age, education, and socioeconomic status) healthy controls produced three oral narratives based on sequential scenes. Voxel-based morphometry analysis was conducted using structural magnetic resonance imaging. Results Compared to healthy controls, the left hemisphere group showed cohesion impairments, whereas the right hemisphere group showed impairments in coherence and in producing macropropositions. Cohesion positively correlated with gray matter density in the right primary sensory area (PSA)/precentral gyrus and the pars opercularis. Coherence, narrativity, and index of lexical informativeness were positively associated with the left PSA/insula and the superior temporal gyrus. Macropropositions were mostly related to the left PSA/insula and superior temporal gyrus, left cingulate, and right primary motor area/insula. Discussion Overall, the present results suggest that both hemispheres are implicated in macrolinguistic processes in narrative discourse. Further studies including larger samples and with various socioeconomic status should be conducted. Supplemental Material https://doi.org/10.23641/asha.14347550

Evidence for a specific regional association between lateral orbitofrontal cortex morphometry and increased appetite in major depression

Increased appetite and body weight are core features of atypical depression. While previous research has consistently highlighted the presence of distinct immunometabolic profiles in atypical depression, little is still known about the neural correlates of atypical symptoms in major depression. Even though obesity and increased body-mass index have frequently been associated with prefrontal brain structural alterations first and foremost in the orbitofrontal cortex (OFC) in healthy and depressed subjects, it is unclear if conceptually related atypical depressive symptoms are associated with similar neural signatures. Here we aimed to investigate associations between appetite and weight change in major depression and OFC morphometry using a multimodal structural neuroimaging approach. We found that increased appetite was associated with significantly lower cortical thickness and lower gray matter density specifically in the right lateral OFC. Further, Bayesian model comparison showed that appetite change was a more informative predictor for changes in cortical thickness and gray matter density compared to body mass index. No conclusive association between appetite change and white matter tracts connected to the right lateral OFC was found. Our findings highlight the relevance of the right lateral OFC for future investigation of the neurobiological underpinnings of the atypical depressive symptom dimensions appetite and weight gain.