Serotonin regulates brain-derived neurotrophic factor expression in select brain regions during acute psychological stress

Previous studies suggest that serotonin （5-HT） might interact with brain-derived neurotrophic factor （BDNF） during the stress response. However, the relationship between 5-HT and BDNF expression under purely psychological stress is unclear. In this study, one hour before psychological stress exposure, the 5-HT1A receptor agonist 8-OH-DPAT or antagonist MDL73005, or the 5-HT2A receptor agonist DOI or antagonist ketanserin were administered to rats exposed to psychological stress. Immunohistochemistry and in situ hybridization revealed that after psychological stress, with the exception of the ventral tegmental area, BDNF protein and mRNA expression levels were higher in the 5-HT1A and the 5-HT2A receptor agonist groups compared with the solvent control no-stress or psychological stress group in the CA1 and CA3 of the hippocampus, prefrontal cortex, central amygdaloid nucleus, dorsomedial hypothalamic nucleus, dentate gyrus, shell of the nucleus accumbens and the midbrain periaqueductal gray. There was no significant difference between the two agonist groups. In contrast, after stress exposure, BDNF protein and mRNA expression levels were lower in the 5-HT1A and 5-HT2A receptor antagonist groups than in the solvent control non-stress group, with the exception of the ventral tegmental area. Our findings suggest that 5-HT regulates BDNF expression in a rat model of acute psychological stress.

Exploring neuroimaging-genetic co-alteration features of auditory verbal hallucinations in different subjects for the establishment of a predictive model

To the Editor: Auditory verbal hallucination (AVH) is defined as the hearing of voices in the absence of any external auditory stimulus.[1,2,3] Most AVH content is related to the experiencer, and these events usually cause serious distress. AVHs can occur in patients with a broad range of mental disorders and neurological diseases, such as schizophrenia, bipolar disorder (BP), major depressive disorder (MDD), post-traumatic stress disorder (PTSD), borderline personality disorder (BPD), and in healthy individuals.[2,3,4]

Antidepressant Effects of Electroconvulsive Therapy Unrelated to the Brain＇s Functional Network Connectivity alterations at an Individual Level

Background： Electroconvulsive therapy （ECT） can alleviate the symptoms of treatment-resistant depression （TRD）. Functional network connectivity （FNC） is a newly developed method to investigate the brain＇s functional connectivity patterns. The first aim of this study was to investigate FNC alterations between TRD patients and healthy controls. The second aim was to explore the relationship between the ECT treatment response and pre-ECT treatment FNC alterations in individual TRD patients. Methods： This study included 82 TRD patients and 41 controls. Patients were screened at baseline and after 2 weeks of treatment with a combination of ECT and antidepressants. Group information guided-independent component analysis （G1G-ICA） was used to compute subject-specific functional networks （FNs）. Grassmann maniibld and step-wise forward component selection using support vector machines were adopted to perform the FNC measure and extract the functional networks＇ connectivity patterns （FCP）. Pearson＇s correlation analysis was used to calculate the correlations between the FCP and ECT response. Results： A total of 82 TRD patients in the ECT group were successfully treated. On an average, 8.50 ~ 2.00 ECT sessions were conducted. After ECT treatment, only 42 TRD patients had an improved response to ECT （the Hamilton scores reduction rate was more than 50%）, response rate 51%. 8 FNs （anterior and posterior default mode network, bilateral frontoparietal network, audio network, visual network, dorsal attention network, and sensorimotor network） were obtained using GIG-ICA. We did not found that FCPs were significantly different between TRD patients and healthy controls. Moreover, the baseline FCP was unrelated to the ECT treatment response. Conclusions： The FNC was not significantly different between the TRD patients and healthy controls, and the baseline FCP was unrelated to the ECT treatment response. These findings will necessitate that we modify the experimental scheme to explore the mechanisms underlying ECT＇s effects on depression and explore the specific predictors of the effects of ECT based on the pre-ECT treatment magnetic resonance imaging.

Brain function differences in drug-nave first-episode auditory verbal hallucination-schizophrenia patients with versus without insight

Background:Few studies have reported brain function differences in drug-na(i)ve first-episode schizophrenia patients who had auditory verbal hallucinations (AVH) with insight vs.those without insight.This study aimed to investigate brain function differences between drug-naive first-episode AVH-schizophrenia patients with and without insight.Methods:Forty first-episode drug-naive AVH-schizophrenia patients with or without insight and 40 healthy controls between December 2016 and December 2018 were recruited in this study.The auditory hallucinations rating scale (AHRS) was used to assess AVH severity,while the insight and treatment attitudes questionnaire was used to distinguish insight.The global functional connectivity density (gFCD) between different groups was compared using a voxel-wise one-way analysis of covariance.The relationship between gFCD and AHRS total scores were analyzed using voxel-wise multiple regression.Results:Finally,13 first-episode drug-naive AVH-schizophrenia patients with insight,15 AVH-schizophrenia patients without insight,and 20 healthy controls were included for analysis.Except for global assessment of functioning scores,there were no significant differences in sociodemographic information between the AVH-schizophrenia and healthy groups (P > 0.05).Compared to the healthy controls,AVH-schizophrenia patients with insight demonstrated a decreased gFCD in the supramarginal gyrus within the primary auditory cortex,while those without insight demonstrated an increased gFCD in the inferior frontal gyrus and superior temporal gyrus and decreased gFCD in the supplemental motor area.Compared to the AVH-schizophrenia patients with insight,those without insight demonstrated an increased gFCD in the supra-marginal gyrus and posterior superior temporal lobule and a decreased gFCD in the frontal lobe.No significant correlation between gFCD and AVH severity (AHRS total score:r =0.23,P =0.590;and frequency:r =0.42,P =0.820) was found in both AVH-schizophrenia groups.Condusions:The gFCD-aberrant brain regions in the AVH-schizophrenia patients without insight were wider compared to those with insight,although the AHRS scores were not significandy different.The AVH-schizophrenia patients without insight had wide functional impairment in the frontal lobule,which may underlie the lack of insight and the abnormal hyperactivity in the inferior frontal gurus and temporal lobe related to the AVH symptoms.

Nonspecific Effect of Stress on Brain Gray Matter Volume in Drug-naive Female Patients with First Depressive Episode

Background： This study aimed to observe the differences in brain gray matter volume in drug-naive female patients after the first episode of major depression with and without stressful life events （SLEs） before the onset of depression.Methods： Forty-three drug-naive female patients voluntarily participated in the present study after the first major depressive episode.The life event scale was used to evaluate the severity of the impact of SLEs during 6 months before the onset of the major depressive episode.High-field magnetic resonance imaging （MRI） scans were obtained, and the VBM and SPM8 software process were used to process and analyze the MRI.Results： Compared to that in patients without SLEs, the volume of brain gray matter was lower in the bilateral temporal lobe, right occipital lobe, and right limbic lobe in the SLE group.However, the gray matter volume did not differ significantly between the two groups after the application of false discovery rate （FDR） correction.Conclusions： Although the results of the present study suggest the absence of significant differences in brain gray matter volume between female drug-naive patients after the first episode of major depression with and without SLEs after FDR correction, the study provides useful information for exploring the definitive role of stress in the onset of depression.