Neuropsychobiology最新文献

Introduction: Functional connectivity is attracting increasing attention for understanding the pathophysiology of depression and predicting the therapeutic efficacy of antidepressants. In this study, we evaluated effective connectivity using isolated effective coherence (iCoh), an effective functional connectivity analysis method developed from low-resolution brain electromagnetic tomography (LORETA) and estimated its practical usefulness for predicting the reaction to antidepressants in theta and alpha band iCoh values.

Methods: We enrolled 25 participants from a depression treatment randomized study (the GUNDAM study) in which electroencephalography was performed before treatment. We conducted iCoh between the rostral anterior cingulate cortex (rACC) and anterior insula (AI), which are associated with the salience network. The patients were divided into responder and nonresponder groups at 4 weeks after the start of treatment, and iCoh values were compared between the two groups. Additionally, the sensitivity and specificity of iCoh were calculated using the receiver-operating characteristic (ROC) curve.

Results: The Mann-Whitney U test showed significantly weaker connectivity flow from the rACC to the left AI in the alpha band in the responder group. The ROC curve for the connectivity flow from the rACC to the left AI in the alpha band showed 82% sensitivity and 86% specificity.

Discussion/conclusion: These findings suggest the pathological importance of effective connectivity flow from the rACC to the left AI in the alpha and theta bands and suggest its usefulness as a biomarker to distinguish responders to antidepressants.

Introduction: The present study compared the mismatch negativity (MMN) and P3a waveforms among early-phase psychosis (EPP; n = 13) individuals and healthy controls (n = 30) to contribute to the research on these waveforms as potential biomarkers for schizophrenia.

Methods: MMN and P3a were elicited with a novelty paradigm using complex stimuli with electrophysiological technology.

Results: No significant group differences of amplitude were observed with either waveform. Increased asociality and blunted affect were associated with a reduction in both MMN and P3a waveforms indicating a relationship between these negative symptoms and cognitive deficits. Good social and occupational functioning correlated with improved MMN and P3a waveforms in the EPP group.

Conclusions: This study suggests that MMN and P3a may be more appropriately used as an indicator of illness progression and symptomology rather than a biomarker in the early phase of the illness.

Background: The precise physiological mechanisms of acupuncture in the treatment of depression are still unknown. This study aimed to observe the effects of electroacupuncture (EA) on depression-like behavior of mouse in chronic mild stress (CMS) model and explore the underlying mechanism.

Methods: The depression model was established by using CMS method for 6 weeks. After the third week of the CMS paradigm, EA treatment was performed daily for 15 min over a period of 3 weeks. The antidepressant-like effects of EA were evaluated using the sucrose preference test and the forced swimming test (FST). The protein levels of the nuclear factor-kappa B (NF-κB), p-NF-κB, inhibitor of NF-κB, p-IκBα, NOD-like receptor protein 3, interleukin (IL)-6, IL-1β, IL-18, and tumor necrosis factor-α (TNF-α) in hippocampus of mice were detected.

Results: Sucrose preference was decreased after 6 weeks of CMS and the effects of CMS was reversed by EA. CMS increased immobility time and decreased latency to the first immobility in the FST test, but these effects were reversed by EA. CMS-induced nuclear entry of NF-κB (nuclear/cytoplasmic ratio of NF-κB) with an increase in protein levels of p-NF-κB and p-IκBα in the hippocampus. The CMS also increased NLRP3 levels in the hippocampus. However, these effects were reversed by EA. In addition, the levels of IL-6, IL-1β, IL-18, and TNF-α in the hippocampus were increased by CMS, and these effects of stress were reversed by EA.

Conclusion: EA prevented CMS-induced depressive-like behaviors by inhibiting NF-κB/NLRP3 inflammatory pathway.

Introduction: Reduced striatal dopamine D2/3 receptor availability in alcohol use disorder (AUD) has been demonstrated in recent clinical studies and meta-analyses. However, only a limited number of studies investigated extrastriatal D2/3 availability in AUD or in at-risk populations. In line with a dimensional understanding of addiction, extrastriatal dopaminergic neuroadaptations have been suggested to be relevant from a pathobiological perspective.

Methods: We investigated D2/3 receptor availability via 18F-fallypride positron emission tomography applying a region of interest (ROI) approach. We selected ROIs for the prefrontal cortex (PFC) and the anterior cingulate cortex (ACC). Our sample included 19 healthy controls (low risk [LR]), 19 individuals at high risk (HR) to develop addiction, and 20 recently detoxified AUD patients.

Results: We found significantly higher D2/3 receptor availability of HR compared to AUD in the left and right rostral ACC (rACC), as well as in the left ventrolateral PFC (vlPFC). We did not observe a significant difference between AUD and LR. After corrections for multiple comparisons none of the ROIs reached significance throughout the group comparison. The D2/3 receptor availability in the left rACC was inversely correlated with symptom severity assessed with the Alcohol Dependency Scale.

Discussion: To our knowledge, the present work is the first study investigating extrastriatal D2/3 receptor availabilities in individuals at HR and patients with AUD. The observation that D2/3 receptor availabilities are highest in HR might suggest that their pathobiology differs from subjects with AUD. Future studies are necessary to clarify the intraindividual course of this biomarker over different disease stages and its possible role as a risk or protective factor.

Introduction: Major depressive disorder (MDD) is a prevalent condition which has a well-known association with ischemic cardiomyopathy, probably explained by an inflammatory mediator mechanism. Statins, besides reducing cholesterol production, have pleiotropic effects including anti-inflammatory activity. The goal was to evaluate the effect of statins as an addition to standard therapy on mood status, brain perfusion, and neurocognitive performance in MDD.

Methods: We studied 20 MDD patients with brain single-photon emission tomography and Cambridge Neuropsychological Test Automated Battery (CANTAB), half randomized to 10 mg of Rosuvastatin or placebo, in addition to selective serotonin reuptake inhibitors (SSRIs) therapy and being reevaluated 3 months later. The images were compared using Statistical Parametric Mapping; clinical scores (Hamilton Depression Score with 17 items and Beck's Depression Inventory) as well as neurocognitive parameters were applied as covariances (CoV) to estimate regional cerebral blood flow (rCBF) changes with both therapies.

Results: Clinical scores decreased in both groups (p = 0.0001); Beck's presented a larger decrease with statins. We observed significantly rCBF changes expressed as significant larger clusters of voxels (p < 0.05) in the pre/subgenual anterior cingulate plus orbitofrontal cortex and a small area in the posterior cingulate gyrus in the statins group, whereas it was not observed with placebo, when using clinical scores as CoV. A similar pattern of rCBF changes was present with emotions recognition, attentional, paired associates learning, spatial planning, and working memory tasks.

Conclusion: Short-term use of low-dose statins in MDD patients under SSRIs results in important rCBF changes in key mood associated areas to improvement in neurocognitive performance. These findings, even though demonstrated in a small sample, could open a new therapeutic tool in the comprehensive management of this disorder.

Introduction: The pathophysiological mechanisms of acute schizophrenia are largely unknown, but it is widely accepted that dopamine D2 receptors (DRD2s) are involved in psychosis treatments for schizophrenic patients. We suggest that genetic variation in these receptors may play a role in patients' responses to commonly used antipsychotics, particularly D2-blockers.

Methods: This study included adult patients with ICD-10 diagnoses of schizophrenia and current acute psychosis who were treated with antipsychotics. All patients underwent genotyping for DRD2 rs2514218 polymorphism. The definition of overall treatment response was based on changes in treatment scheme: no changes indicated a good response, and changes indicated a limited response.

Results: There were 275 inpatients (38.1% of whom were female; mean age = 32.7 years, SD = 11.1 years) who met the inclusion criteria. Of the participants, 99 were good responders (34% of whom were female), and 176 were limited responders (40% of whom were female). No differences in demographic, premorbid, or disease characteristics were found. The number of patients that were homozygous for the risk allele was significantly greater in the limited response group than in the good response group.

Conclusion: Our findings suggest that the risk variant at the DRD2 locus can be used as an indicator for patients' responses to antipsychotics without direct DRD2-blocking, thereby shortening the time needed for drug selection.

Introduction: In recent years, research on posttraumatic stress disorder (PTSD) focused on the description of different biological correlates of illness. Morphological changes of different brain regions were involved in PTSD neurophysiopathology, being related to trauma or considered a resilience biomarker. In this meta-analysis, we aimed to investigate the grey matter changes reported in magnetic resonance imaging (MRI) studies on patients who have developed PTSD compared to exposed subjects who did not show a clinical PTSD onset.

Methods: We meta-analysed eight peer-reviewed MRI studies conducted on trauma-exposed patients and reported results corrected for false positives. We then conducted global and intergroup comparisons from neuroimaging data of two cohorts of included subjects. The included studies were conducted on 250 subjects, including 122 patients with PTSD and 128 non-PTSD subjects exposed to trauma.

Results: Applying a family-wise error correction, PTSD subjects compared to trauma-exposed non-PTSD individuals showed a significant volume reduction of a large left-sided grey matter cluster extended from the parahippocampal gyrus to the uncus, including the amygdala.

Conclusions: These volumetric reductions are a major structural correlate of PTSD and can be related to the expression of symptoms. Future studies might consider these and other neural PTSD correlates, which may lead to the development of clinical applications for affected patients.

Background: The "cognitive dysmetria hypothesis" of schizophrenia proposes a disrupted communication between the cerebellum and cerebral cortex, resulting in sensorimotor and cognitive symptoms. Sensorimotor adaptation relies strongly on the function of the cerebellum.

Objectives: This study investigated whether sensorimotor adaptation is reduced in schizophrenia compared with age-matched and elderly healthy controls.

Methods: Twenty-nine stably treated patients with schizophrenia, 30 age-matched, and 30 elderly controls were tested in three motor adaptation tasks in which visual movement feedback was unexpectedly altered. In the "rotation adaptation task" the perturbation consisted of a rotation (30° clockwise), in the "gain adaptation task" the extent of the movement feedback was reduced (by a factor of 0.7) and in the "vertical reversal task," up- and downward pen movements were reversed by 180°.

Results: Patients with schizophrenia adapted to the perturbations, but their movement times and errors were substantially larger than controls. Unexpectedly, the magnitude of adaptation was significantly smaller in schizophrenia than elderly participants. The impairment already occurred during the first adaptation trials, pointing to a decline in explicit strategy use. Additionally, post-adaptation aftereffects provided strong evidence for impaired implicit adaptation learning. Both negative and positive schizophrenia symptom severities were correlated with indices of the amount of adaptation and its aftereffects.

Conclusions: Both explicit and implicit components of sensorimotor adaptation learning were reduced in patients with schizophrenia, adding to the evidence for a role of the cerebellum in the pathophysiology of schizophrenia. Elderly individuals outperformed schizophrenia patients in the adaptation learning tasks.

Introduction: Hypothalamic-pituitary-adrenal (HPA) axis dysregulation may contribute to the symptom burden in bipolar disorder (BD). Further characterization of cortisol secretion is needed to improve understanding of the connection between mood, sleep, and the HPA axis. Here, we observe diurnal cortisol patterns in individuals with BD and healthy controls (HCs) to determine time points where differences may occur.

Methods: Salivary cortisol was measured at 6 time points (wake, 15, 30, and 45 min after wake, between 2:00 and 4:00 p.m. and 10:00 p.m.) for 3 consecutive days in individuals with symptomatic BD (N = 27) and HC participants (N = 31). A general linear model with correlated errors was utilized to determine if salivary cortisol changed differently throughout the day between the 2 study groups.

Results: A significant interaction (F = 2.74, df = 5, and p = 0.02) was observed between the time of day and the study group (BD vs. HC) when modeling salivary cortisol over time, indicating that salivary cortisol levels throughout the day significantly differed between the study groups. Specifically, salivary cortisol in BD was elevated compared to HCs at the 10:00 p.m. time point (p = 0.01).

Conclusion: Significantly higher levels of cortisol in participants with BD in the night-time suggest that the attenuation of cortisol observed in healthy individuals may be impaired in those with BD. Reregulation of cortisol levels may be a target of further study and treatment intervention for individuals with BD.

Introduction: Recently, several mindfulness-based programs showed promising clinical effects in the treatment of psychiatric disorders including substance use disorders. However, very little is known about the effects of mindfulness-based interventions (MBIs) on brain structure in such patients.

Methods: This study aimed to detect changes in gray matter volume (GMV) in opioid-dependent patients receiving MBI during their first month of treatment. Thirty patients were assigned to either 3 weeks of MBI (n = 16) or treatment as usual (TAU, n = 14) and were investigated using structural magnetic resonance imaging before and after treatment. Longitudinal pipeline of the Computational Anatomy Toolbox for SPM (CAT12) was used to detect significant treatment-related changes over time. The identified GMV changes following treatment were related to clinically relevant measures such as impulsivity, distress tolerance, and mindfulness.

Results: After treatment, increased mindfulness scores were found in individuals receiving MBI compared to TAU. In the MBI group, there were also significant differences with respect to distress tolerance and impulsivity. Effects on mindfulness, distress tolerance, and impulsivity were also found in the TAU group. Longitudinal within-group analysis revealed increased left anterior insula GMV in individuals receiving MBI. Anterior insula volume increase was associated with decreased impulsivity levels. In the TAU group, significant GMV changes were found in the right lingual gyrus and right entorhinal cortex.

Discussion/conclusion: MBI can yield significant clinical effects during early abstinence from opioid dependence. MBI is particularly associated with increased insula GMV, supporting an important role of this region in the context of MBI-induced neural changes.