Intermittent Theta-Burst Stimulation Transcranial Magnetic Stimulation Increases GABA in the Medial Prefrontal Cortex: A Preliminary Sham-Controlled Magnetic Resonance Spectroscopy Study in Acute Bipolar Depression

The effect of noninvasive brain stimulation on anhedonia in patients with schizophrenia and depression: A systematic review and meta-analysis

Anhedonia is a transdiagnostic symptom found in patients with schizophrenia and depression. Current pharmacological interventions for anhedonia are unsatisfactory in a considerable proportion of patients. There has been growing interest in applying noninvasive brain stimulation (NIBS) to patients with anhedonia. However, evidence for the efficacy of NIBS for anhedonia remain inconsistent. This study systematically identified all studies that measured anhedonia and applied NIBS in patients with schizophrenia or depression. We conducted a search using the various databases in English (PubMed, EBSCOHost (PsycInfo/PsycArticles), Web of Science) and Chinese (China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform) languages, and reviewed original research articles on NIBS published from January 1989 to July 2023. Our search had identified 15 articles for quantitative synthesis, with three concerning schizophrenia samples, 11 concerning samples with depression, and one concerning both clinical samples. We conducted a meta-analysis based on the 15 included studies, and the results suggested that NIBS could improve anhedonia symptoms in schizophrenia patients and patients with depression, with a medium-to-large effect size. Our findings are preliminary, given the limited number of included studies. Future NIBS research should measure anhedonia as a primary outcome and should recruit transdiagnostic samples.

GABAA Receptor Availability in Relation to Cortical Excitability in Depressed and Healthy: A Positron Emission Tomography and Transcranial Magnetic Stimulation Study

INTRODUCTION

Gamma-aminobutyric acid (GABA) deficiency is suggested in depressive disorders, along with alterations in cortical excitability. However, whether these excitability changes are related to GABAA receptor availability is largely unknown. Our aim was to assess the correlation between these measures in depressed patients and healthy controls.

METHODS

Twenty-eight patients with a major depressive episode, measured before and after participating in a clinical trial with repetitive transcranial magnetic stimulation (TMS), and 15 controls underwent [11C]flumazenil positron emission tomography to assess GABAA receptor availability and paired pulse TMS (ppTMS) to evaluate cortical excitability. Both whole-brain voxel-wise GABAA receptor availability and mean values from left hand motor cortex and left paracentral lobule were correlated to the ppTMS outcomes: short-interval intracortical inhibition reflecting GABAA receptor activity, long-interval intracortical inhibition representing GABAB receptor activity, intracortical facilitation reflecting glutamate N-methyl-D-aspartate-receptor activity, as well as the resting motor threshold (rMT), considered a global measure of corticospinal excitability.

RESULTS

No significant differences in baseline GABAA receptor availability or cortical excitability were found between patients and controls. Additionally, no correlations were observed between baseline measurements of GABAA receptor availability and TMS outcomes. Changes in GABAA receptor availability in the hand motor cortex, between pre- and post-assessments, were inversely related to pre-post changes in hand rMT.

CONCLUSION

We found that a change in GABAA receptor availability was inversely related to a change in rMT, suggesting a link between GABA deficiency and increased rMT previously observed in depressive episodes. The results highlight the complex mechanisms governing cortical excitability measures and offer new insight into their properties during the depressive state.

Are we really targeting and stimulating DLPFC by placing transcranial electrical stimulation (tES) electrodes over F3/F4?

In many clinical trials involving transcranial electrical stimulation (tES), target electrodes are typically placed over DLPFC with the assumption that this will primarily stimulate the underlying brain region. However, our study aimed to evaluate the electric fields (EF) that are actually delivered and identify prefrontal regions that may be inadvertently targeted in DLPFC tES. Head models were generated from the Human Connectome Project database's T1 + T2-weighted MRIs of 80 healthy adults. Two common DLPFC montages were simulated; symmetric-F4/F3, and asymmetric-F4/Fp1. Averaged EF was extracted from (1) the center of the target electrode (F4), and (2) the top 1% of voxels showing the strongest EF in individualized EF maps. Interindividual variabilities were quantified with the standard deviation of EF peak location/value. Similar steps were repeated with 66 participants with methamphetamine use disorder (MUDs) as an independent clinical population. In healthy adults, the group-level location of EF peaks was situated in the medial-frontopolar, and the individualized EF peaks were positioned in a cube with a volume of 29 cm3 /46 cm3 (symmetric/asymmetric montages). EFs in the frontopolar area were significantly higher than EF "under" the target electrode in both symmetric (peak: 0.41 ± 0.06, F4:0.22 ± 0.04) and asymmetric (peak: 0.38 ± 0.04, F4:0.2 ± 0.04) montages (Heges'g > 0.7). Similar results with slight between-group differences were found in MUDs. We highlighted that in common DLPFC tES montages, in addition to interindividual/intergroup variability, the frontopolar received the highest EFs rather than DLPFC as the main target. We specifically recommended considering the potential involvement of the frontopolar area as a mechanism underlying the effectiveness of DLPFC tES protocols.

Neuroimaging Correlates of Treatment Response to Transcranial Magnetic Stimulation in Bipolar Depression: A Systematic Review

Transcranial magnetic stimulation (TMS) has become a promising strategy for bipolar disorder (BD). This study reviews neuroimaging findings, indicating functional, structural, and metabolic brain changes associated with TMS in BD. Web of Science, Embase, Medline, and Google Scholar were searched without any restrictions for studies investigating neuroimaging biomarkers, through structural magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), functional MRI (fMRI), magnetic resonance spectroscopy (MRS), positron emission tomography (PET), and single photon emission computed tomography (SPECT), in association with response to TMS in patients with BD. Eleven studies were included (fMRI = 4, MRI = 1, PET = 3, SPECT = 2, and MRS = 1). Important fMRI predictors of response to repetitive TMS (rTMS) included higher connectivity of emotion regulation and executive control regions. Prominent MRI predictors included lower ventromedial prefrontal cortex connectivity and lower superior frontal and caudal middle frontal volumes. SPECT studies found hypoconnectivity of the uncus/parahippocampal cortex and right thalamus in non-responders. The post-rTMS changes using fMRI mostly showed increased connectivity among the areas neighboring the coil. Increased blood perfusion was reported post-rTMS in PET and SPECT studies. Treatment response comparison between unipolar depression and BD revealed almost equal responses. Neuroimaging evidence suggests various correlates of response to rTMS in BD, which needs to be further replicated in future studies.

Neurostimulation as a treatment for mood disorders in patients: recent findings

PURPOSE OF REVIEW

The use of neurostimulation to treat mood disorders dates back to the 1930s. Recent studies have explored various neurostimulation methods aimed at both restoring a healthy brain and reducing adverse effects in patients. The purpose of this review is to explore the most recent hypotheses and clinical studies investigating the effects of stimulating the brain on mood disorders.

RECENT FINDINGS

Recent work on brain stimulation and mood disorders has focused mainly on three aspects: enhancing efficacy and safety by developing new approaches and protocols, reducing treatment duration and chances of relapse, and investigating the physiological and pathological mechanisms behind treatment outcomes and possible adverse effects.This review includes some of the latest studies on both noninvasive techniques, such as transcranial magnetic stimulation, magnetic seizure therapy, transcranial direct current stimulation, transcranial alternating current stimulation, electroconvulsive treatment, and invasive techniques, such as deep brain stimulation and vagus nerve stimulation.

SUMMARY

Brain stimulation is widely used in clinical settings; however, there is a lack of understanding about its neurobiological mechanism. Further studies are needed to understand the neurobiology of brain stimulation and how it can be used to treat mood disorders in their diversity, including comorbidities with other illnesses.

Baihe Dihuang (Lilium Henryi Baker and Rehmannia Glutinosa) decoction attenuates somatostatin interneurons deficits in prefrontal cortex of depression via miRNA-144-3p mediated GABA synthesis and release

ETHNOPHARMACOLOGICAL RELEVANCE

Baihe Dihuang Decoction is a well-known traditional Chinese medicine prescription (Also known as Lilium Henryi Baker and Rehmannia Glutinosa Decoction, LBRD) composed of Lilium Henryi Baker bulb and raw juice from Rehmannia Glutinosa (Gaertn) DC with the curative efficacy of nourishing yin and clearing heat based on the Chinese herbal medicine theory. It has been used as routine medication in treating depression combined with conventional western medicine in China for years.

AIM OF THE STUDY

LBRD can attenuates GABAergic deficits in the medial prefrontal cortex (mPFC) of depression. This study aimed to investigate the mechanism of antidepressive properties of LBRD in the prefrontal GABAergic interneuron subtypes, including parvalbumin (PV), somatostatin (SST), vasoactive intestinal peptide (VIP)-positive neuron.

MATERIALS AND METHODS

In this project, chronic unpredicted mild stress paradigm was adopted to construct depression model. After treated with LBRD standard decoction and behaviors test, the level of GABA associated miRNA/mRNA and GABAergic subtype-specific markers were detected by qRT-PCR and Western blot. The lncRNAs/miRNAs/GABA regulatory axis was verified by luciferase reporter assay, RNA immunoprecipitation, RNA pull-down assay, and theses changes were measured in LBRD administration with the use of immunofluorescence staining and RNA-fluorescence in situ hybridization.

RESULTS

In the current study, we found that LBRD exhibited high efficacy based on the results of behavioral tests. Meanwhile, LBRD also improved the reduced GABA levels in depression by increasing the expression of lncRNA Neat1 and Malat1, as well as decreasing miRNA-144-3p and miRNA-15b-5p. Moreover, the level of Sst mRNA and protein that were harvested from the mPFC tissues of depression group was significantly lower than those in the control mice. While, these changes can be reverted by LBRD standard decoction administration. Whereas, neither chronic stress nor treatment can change the level of PV and VIP mRNAs and protein expression. In the SST-positive neuron of mPFC tissues, treatment with LBRD standard decoction resulted in the elevation of Gad-67, VGAT, GAT-3 and a reduction of miRNA-144-3p expression.

CONCLUSIONS

These findings suggested that LBRD antidepressant activities may be related to ameliorating the SST-positive neuron deficits via regulating the miRNA-144-3p mediated GABA synthesis and release.

Integrated analysis of the chemical-material basis and molecular mechanisms for the classic herbal formula of Lily Bulb and Rehmannia Decoction in alleviating depression

BACKGROUND

Lily Bulb and Rehmannia Decoction (LBRD), is a traditional Chinese formula that has been shown to be safe and effective against depression; however, its material basis and pharmacological mechanisms remain unknown.

METHODS

Here, ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) and high-performance liquid chromatography (HPLC) were used to identify the chemical spectrum and qualitatively identify the major active ingredients in the LBRD standard decoction, respectively. Subsequently, we assessed the behavior, neuronal function and morphology, neurotransmitter levels, hypothalamic-pituitary-adrenal (HPA)-axis associated hormones, inflammatory cytokine levels, and miRNA/mRNA expression alterations in an in vitro/vivo depression model treated by the LBRD standard decoction. Finally, miRNA/mRNA regulatory networks were created through bioinformatics analysis, followed by functional experiments to verify its role in LBRD standard decoction treatment.

RESULTS

A total of 32 prototype compounds were identified in the LBRD standard decoction, and the average quality of verbascoside in the fresh lily bulb decoction, fresh raw Rehmannia juice, and the LBRD standard decoction were 0.001264%, 0.002767%, and 0.009046% (w/w), respectively. Administration of the LBRD standard decoction ameliorated chronic unpredictable mild stress (CUMS)-induced depression-like phenotypes and protected PC12 cells against chronic corticosterone (CORT)-induced injury. The levels of neurotransmitter, cytokine, stress hormones and neuronal morphology were disrupted in the depression model, while LBRD standard decoction could work on these alterations. After LBRD standard decoction administration, four differentially expressed miRNAs, rno-miR-144-3p, rno-miR-495, rno-miR-34c-5p, and rno-miR-24-3p, and six differentially expressed mRNAs, Calml4, Ntrk2, VGAT, Gad1, Nr1d1, and Bdnf overlapped in the in vivo/vitro depression model. Among them, miR-144-3p directly mediated GABA synthesis and release by targeting Gad1 and VGAT, and miR-495 negatively regulated BDNF expression. The LBRD standard decoction can reverse the above miRNA/mRNA network-mediated GABA and BDNF expression in the in vivo/vitro depression model.

CONCLUSION

Collectively, the multi-components of the LBRD standard decoction altered a series of miRNAs in depression through mediating GABAergic synapse, circadian rhythm, and neurotrophic signaling pathway etc., thereby abolishing inhibitory/excitatory neurotransmitter deficits, recovering the pro-/anti-inflammatory cytokine levels and regulating the HPA-axis hormone secretion to achieve balance of the physiological function of the whole body.

Predictive Role of Executive Function in the Efficacy of Intermittent Theta Burst Transcranial Magnetic Stimulation Modalities for Treating Methamphetamine Use Disorder-A Randomized Clinical Trial

Background: Repetitive transcranial magnetic stimulation (rTMS) has therapeutic effects on craving in methamphetamine (METH) use disorder (MUD). The chronic abuse of METH causes impairments in executive function, and improving executive function reduces relapse and improves treatment outcomes for drug use disorder. The purpose of this study was to determine whether executive function helped predict patients' responses to rTMS treatment. Methods: This study employed intermittent theta burst stimulation (iTBS) rTMS modalities and observed their therapeutic effects on executive function and craving in MUD patients. MUD patients from an isolated Drug Rehabilitation Institute in China were chosen and randomly allocated to the iTBS group and sham-stimulation group. All participants underwent the Behavior Rating Inventory of Executive Function - Adult Version Scale (BRIEF-A) and Visual Analog Scales (VAS) measurements. Sixty-five healthy adults matched to the general condition of MUD patients were also recruited as healthy controls. Findings: Patients with MUD had significantly worse executive function. iTBS groups had better treatment effects on the MUD group than the sham-stimulation group. Further Spearman rank correlation and stepwise multivariate regression analysis revealed that reduction rates of the total score of the BRIEF-A and subscale scores of the inhibition factor and working memory factor in the iTBS group positively correlated with improvements in craving. ROC curve analysis showed that working memory (AUC = 87.4%; 95% CI = 0.220, 0.631) and GEC (AUC = 0.761%; 95% CI = 0.209, 0.659) had predictive power to iTBS therapeutic efficacy. The cutoff values are 13.393 and 59.804, respectively. Conclusions: The iTBS rTMS had a better therapeutic effect on the executive function of patients with MUD, and the improved executive function had the potential to become a predictor for the efficacy of iTBS modality for MUD treatment. Clinical Trial Registration: ClinicalTrials.gov, identifier: ChiCTR2100046954.