Resting-State Functional Connectivity between Putamen and Salience Network and Childhood Body Mass Index

The neural substrates responsible for punishment sensitivity association with procrastination: Left putamen connectivity with left middle temporal gyrus

Procrastination has adverse consequences across cultural contexts. Behavioral research found a positive correlation between punishment sensitivity and procrastination. However, little is known about the neural substrates underlying the association between them. We employed voxel-based morphometry (VBM) and resting-state functional connectivity (RSFC) methods to address this issue with two independent samples. In Sample 1, behavioral results found that punishment sensitivity was positively related to procrastination. The VBM analysis showed that punishment sensitivity was negatively correlated with gray matter volume in left putamen. Subsequently, the RSFC results revealed that left putamen - left middle temporal gyrus (MTG) connectivity was positively associated with punishment sensitivity. More crucially, mediation analysis indicated that left putamen - left MTG connectivity mediated the relationship between punishment sensitivity and procrastination. The aforementioned results were validated in Sample 2. Altogether, left putamen - left MTG connectivity might be the neural signature of the association between punishment sensitivity and procrastination.

Exposure to gestational diabetes mellitus in utero impacts hippocampal functional connectivity in response to food cues in children

Objectives

Intrauterine exposure to gestational diabetes mellitus (GDM) increases the risk of obesity in the offspring, but little is known about the underlying neural mechanisms. The hippocampus is crucial for food intake regulation and is vulnerable to the effects of obesity. The purpose of the study was to investigate whether GDM exposure affects hippocampal functional connectivity during exposure to food cues using functional magnetic resonance imaging.

Methods

Participants were 90 children age 7-11 years (53 females) who underwent an fMRI-based visual food cue task in the fasted state. Hippocampal functional connectivity (FC) was examined using generalized psychophysiological interaction in response to high-calorie food versus non-food cues. Food-cue induced hippocampal FC was compared between children with and without GDM exposure, while controlling for possible confounding effects of age, sex and waist-to-hip ratio.

Results

Children with GDM exposure exhibited stronger hippocampal FC to the insula and striatum (i.e., putamen, pallidum and nucleus accumbens) compared to unexposed children, while viewing high caloric food cues.

Conclusions

Intrauterine exposure to GDM was associated with higher food-cue induced hippocampal FC to reward processing regions. Future studies with longitudinal measurements are needed to clarify whether increased hippocampal FC to reward processing regions may raise the risk of the development of metabolic diseases later in life.

Robust sex differences in functional brain connectivity are present in utero

Sex-based differences in brain structure and function are observable throughout development and are thought to contribute to differences in behavior, cognition, and the presentation of neurodevelopmental disorders. Using multiple support vector machine (SVM) models as a data-driven approach to assess sex differences, we sought to identify regions exhibiting sex-dependent differences in functional connectivity and determine whether they were robust and sufficiently reliable to classify sex even prior to birth. To accomplish this, we used a sample of 110 human fetal resting state fMRI scans from 95 fetuses, performed between 19 and 40 gestational weeks. Functional brain connectivity patterns classified fetal sex with 73% accuracy. Across SVM models, we identified features (functional connections) that reliably differentiated fetal sex. Highly consistent predictors included connections in the somatomotor and frontal areas alongside the hippocampus, cerebellum, and basal ganglia. Moreover, high consistency features also implicated a greater magnitude of cross-region connections in females, while male weighted features were predominately within anatomically bounded regions. Our findings indicate that these differences, which have been observed later in childhood, are present and reliably detectable even before birth. These results show that sex differences arise before birth in a manner that is consistent and reliable enough to be highly identifiable.

Associations of leptin and corticostriatal connectivity in bipolar disorder

Bipolar disorder (BD) and metabolic disturbance represent a chronic state of low-grade inflammation and corticostriatal circuitry alterations. Herein, we aimed to investigate whether plasma leptin, an adipokine that plays a key role in the interplay of metabolism and inflammation, is associated with corticostriatal connectivity in patients with BD. Twenty-eight BD I patients, 36 BD II patients and 66 healthy controls were enrolled and completed the Hamilton Depression Rating Scale, the Young Mania Rating Scale, and the Recent Life Change Questionnaire. Fasting plasma leptin and C-reactive protein (CRP) levels were measured, and corticostriatal connectivity was examined using functional magnetic resonance imaging (fMRI). The relationships between leptin, CRP and body mass index (BMI) identified in the controls and BD II patients were absent in the BD I patients. We did not find a significant group difference in the leptin level; nevertheless, the negative correlation between leptin level and corticostriatal connectivity (ventrolateral prefrontal cortex and inferior temporal gyrus) observed in the healthy controls was absent in the BD patients. The disproportionate increase in leptin level with increasing BMI in BD indicated a potential inflammatory role of white adipose tissue in BD. Furthermore, higher CRP levels in BD I patients might induce leptin resistance. Collectively, our results implied vulnerability to inflammatory and metabolic diseases in patients with BD, especially BD I.