Abnormal cortical-striatal-thalamic-cortical circuit centered on the thalamus in MDD patients with somatic symptoms: Evidence from the REST-meta-MDD project.

OBJECTIVE: Somatic symptoms are common comorbidities of major depressive disorder (MDD), and negatively impact the course and severity of the disease. In order to enrich the understanding of the pathological mechanism and clarify the neurobiological basis of somatic symptoms in depression, we attempted to explore the changes of brain structure and function in a large sample between depression with and without somatic symptoms. METHODS: Structure magnetic resonance imaging (MRI) data were collected from 342 patients with somatic symptoms (SD), 208 patients without somatic symptoms (NSD), and 510 healthy controls (HCs) based on the REST-meta-MDD project. We analyzed the whole brain VBM maps of the three groups, and combined with weight degree centrality (DC) index, we investigated whether the brain regions with gray matter volume (GMV) and gray matter density (GMD) abnormalities in MDD patients with somatic symptoms had corresponding brain functional abnormalities. RESULTS: Between depression with and without somatic symptoms, we found that there are extensive GMV and GMD differences involving cortical regions such as the temporal lobe, occipital lobe, and insula, as well as subcortical brain regions such as thalamus and striatum. The comparison results of weight DC signals of GMV and GMD abnormal clusters between the SD and NSD groups were basically consistent with the GMV and GMD abnormal clusters. CONCLUSION: The results indicate that the structure and function of cortical-striatal-thalamic-cortical (CSTC) circuit centered on the thalamus were abnormal in MDD patients with somatic symptoms. This may be the neurobiological basis of somatic symptoms in MDD.

Brain structural alterations in MDD patients with gastrointestinal symptoms: Evidence from the REST-meta-MDD project.

OBJECTIVE: While gastrointestinal (GI) symptoms are very common in patients with major depressive disorder (MDD), few studies have investigated the neural basis behind these symptoms. In this study, we sought to elucidate the neural basis of GI symptoms in MDD patients by analyzing the changes in regional gray matter volume (GMV) and gray matter density (GMD) in brain structure. METHOD: Subjects were recruited from 13 clinical centers and categorized into three groups, each of which is based on the presence or absence of GI symptoms: the GI symptoms group (MDD patients with at least one GI symptom), the non-GI symptoms group (MDD patients without any GI symptoms), and the healthy control group (HCs). Structural magnetic resonance images (MRI) were collected of 335 patients in the GI symptoms group, 149 patients in the non-GI symptoms group, and 446 patients in the healthy control group. The 17-item Hamilton Depression Rating Scale (HAMD-17) was administered to all patients. Correlation analysis and logistic regression analysis were used to determine if there was a correlation between the altered brain regions and the clinical symptoms. RESULTS: There were significantly higher HAMD-17 scores in the GI symptoms group than that of the non-GI symptoms group (P < 0.001). Both GMV and GMD were significant different among the three groups for the bilateral superior temporal gyrus, bilateral middle temporal gyrus, left lingual gyrus, bilateral caudate nucleus, right Fusiform gyrus and bilateral Thalamus (GRF correction, cluster-P < 0.01, voxel-P < 0.001). Compared to the HC group, the GI symptoms group demonstrated increased GMV and GMD in the bilateral superior temporal gyrus, and the non-GI symptoms group demonstrated an increased GMV and GMD in the right superior temporal gyrus, right fusiform gyrus and decreased GMV in the right Caudate nucleus (GRF correction, cluster-P < 0.01, voxel-P < 0.001). Compared to the non-GI symptoms group, the GI symptoms group demonstrated significantly increased GMV and GMD in the bilateral thalamus, as well as decreased GMV in the bilateral superior temporal gyrus and bilateral insula lobe (GRF correction, cluster-P < 0.01, voxel-P < 0.001). While these changed brain areas had significantly association with GI symptoms (P < 0.001), they were not correlated with depressive symptoms (P > 0.05). Risk factors for gastrointestinal symptoms in MDD patients (p < 0.05) included age, increased GMD in the right thalamus, and decreased GMV in the bilateral superior temporal gyrus and left Insula lobe. CONCLUSION: MDD patients with GI symptoms have more severe depressive symptoms. MDD patients with GI symptoms exhibited larger GMV and GMD in the bilateral thalamus, and smaller GMV in the bilateral superior temporal gyrus and bilateral insula lobe that were correlated with GI symptoms, and some of them and age may contribute to the presence of GI symptoms in MDD patients.

Functional connectivity between the thalamus and the primary somatosensory cortex in major depressive disorder: a resting-state fMRI study.

BACKGROUND: Studies have confirmed that the thalamus and the primary somatosensory cortex (SI) are associated with cognitive function. These two brain regions are closely related in structure and function. The interactions between SI and the thalamus are of crucial significance for the cognitive process. Patients with major depressive disorder (MDD) have significant cognitive impairment. Based on these observations, we used resting-state functional magnetic resonance imaging (rs-fMRI) to investigate whether there is an abnormality in the SI-thalamic functional connection in MDD. Furthermore, we explored the clinical symptoms related to this abnormality. METHODS: We included 31 patients with first-episode major depressive disorder and 28 age-, gender-, and education-matched healthy controls (HC). The SI-thalamic functional connectivity was compared between the MDD and HC groups. The correlation analyses were performed between areas with abnormal connectivity and clinical characteristics. RESULTS: Compared with healthy subjects, the MDD patients had enhanced functional connectivity between the thalamus and SI (p < 0.05, corrected). Brain areas with significantly different levels of connectivity had a negative correlation with the Assessment of Neuropsychological Status total score (r = - 0.383, p = 0.033), delayed memory score (r = - 0.376, p = 0.037) and two-digit continuous operation test score (r = - 0.369, p = 0.041) in MDD patients. CONCLUSIONS: These results demonstrate that SI-thalamic functional connectivity is abnormal and associated with the core clinical symptoms in MDD. The SI-thalamic functional connectivity functions as a neurobiological feature and potential biomarker for MDD.

[Study on the adsorption behaviors of cadmium and lead ions on green tea and black tea by ICP-AES].

The adsorption behaviors of Cd(II) and Pb(II) on green tea and black tea in aqueous solution as well as the influences of time, acidity and temperature on the adsorption have been studied. It was found that Cd(II) and Pb(II) can been adsorbed strongly by green tea and black tea samples. The adsorption effects depend on the pH strongly when pH<4. The recovery of Pb(II) on tea samples is more than that of Cd(II) when pH<6 and it is opposite when pH>6. It is difficult to elute Cd(II) and Pb(II) from tea samples by water at 25 degrees C.