Altered canonical and striatal-frontal resting state functional connectivity in children with pathogenic variants in the Ras/mitogen-activated protein kinase pathway

Differential role of negative and positive parenting styles on resting-state brain networks in middle-aged adolescents

Parenting styles encompass negative and positive approaches, potentially affecting adolescents' brain reward and emotion regulation systems. However, the association between parenting style and brain networks remains unknown. This study investigates the link between parenting style and functional connectivity (FC) within the reward and emotion regulation brain networks, using resting-state functional magnetic resonance imaging (rs-fMRI). A total of forty-two middle-aged adolescents (26 males; 16 females) with no neurological or psychiatric symptoms participated in this study. We assessed parenting behaviors and extracted reward/emotion regulation FC from rs-fMRI. We examined the association between FC and parenting style, identified through principal component analysis. Correlation analysis investigated these links while controlling for sex. We delineated both positive (love-autonomy) and negative (hostility-control) parenting styles, accounting for 79 % of the explained variance in parenting behaviors. The negative parenting style displayed connections with FC within the reward system, particularly in the left nucleus accumbens (NAc), showcasing links to multiple frontal regions. Furthermore, it correlated with the social reward network, specifically the insula-NAc FC in bilateral hemispheres. Conversely, the positive parenting style exhibited an association with FC between the hippocampus and right lateral prefrontal cortex. Our findings support negative parenting's association with an immature reward system and suggest positive parenting's potential to enhance emotion regulation in brain function. These observations highlight two distinct parenting styles, including single-parenting behaviors. Thus, we advance understanding of each style's unique contributions to adolescent reward- and emotion regulation-related brain network development.

Quantitative proteomic and phosphoproteomic analyses of the hippocampus reveal the involvement of NMDAR1 signaling in repetitive mild traumatic brain injury

The cumulative damage caused by repetitive mild traumatic brain injury can cause long-term neurodegeneration leading to cognitive impairment. This cognitive impairment is thought to result specifically from damage to the hippocampus. In this study, we detected cognitive impairment in mice 6 weeks after repetitive mild traumatic brain injury using the novel object recognition test and the Morris water maze test. Immunofluorescence staining showed that p-tau expression was increased in the hippocampus after repetitive mild traumatic brain injury. Golgi staining showed a significant decrease in the total density of neuronal dendritic spines in the hippocampus, as well as in the density of mature dendritic spines. To investigate the specific molecular mechanisms underlying cognitive impairment due to hippocampal damage, we performed proteomic and phosphoproteomic analyses of the hippocampus with and without repetitive mild traumatic brain injury. The differentially expressed proteins were mainly enriched in inflammation, immunity, and coagulation, suggesting that non-neuronal cells are involved in the pathological changes that occur in the hippocampus in the chronic stage after repetitive mild traumatic brain injury. In contrast, differentially expressed phosphorylated proteins were mainly enriched in pathways related to neuronal function and structure, which is more consistent with neurodegeneration. We identified N-methyl-D-aspartate receptor 1 as a hub molecule involved in the response to repetitive mild traumatic brain injury , and western blotting showed that, while N-methyl-D-aspartate receptor 1 expression was not altered in the hippocampus after repetitive mild traumatic brain injury, its phosphorylation level was significantly increased, which is consistent with the omics results. Administration of GRP78608, an N-methyl-D-aspartate receptor 1 antagonist, to the hippocampus markedly improved repetitive mild traumatic brain injury-induced cognitive impairment. In conclusion, our findings suggest that N-methyl-D-aspartate receptor 1 signaling in the hippocampus is involved in cognitive impairment in the chronic stage after repetitive mild traumatic brain injury and may be a potential target for intervention and treatment.

Aberrant Cortical Layer Development of Brain Organoids Derived from Noonan Syndrome-iPSCs

Noonan syndrome (NS) is a genetic disorder mainly caused by gain-of-function mutations in Src homology region 2-containing protein tyrosine phosphatase 2 (SHP2). Although diverse neurological manifestations are commonly diagnosed in NS patients, the mechanisms as to how SHP2 mutations induce the neurodevelopmental defects associated with NS remain elusive. Here, we report that cortical organoids (NS-COs) derived from NS-induced pluripotent stem cells (iPSCs) exhibit developmental abnormalities, especially in excitatory neurons (ENs). Although NS-COs develop normally in their appearance, single-cell transcriptomic analysis revealed an increase in the EN population and overexpression of cortical layer markers in NS-COs. Surprisingly, the EN subpopulation co-expressing the upper layer marker SATB2 and the deep layer maker CTIP2 was enriched in NS-COs during cortical development. In parallel with the developmental disruptions, NS-COs also exhibited reduced synaptic connectivity. Collectively, our findings suggest that perturbed cortical layer identity and impeded neuronal connectivity contribute to the neurological manifestations of NS.