Vulnerable brain regions in adolescent major depressive disorder:A resting-state functional magnetic resonance imaging activation likelihood estimation meta-analysis

BACKGROUND Adolescent major depressive disorder(MDD)is a significant mental health concern that often leads to recurrent depression in adulthood.Resting-state functional magnetic resonance imaging(rs-fMRI)offers unique insights into the neural mechanisms underlying this condition.However,despite previous research,the specific vulnerable brain regions affected in adolescent MDD patients have not been fully elucidated.AIM To identify consistent vulnerable brain regions in adolescent MDD patients using rs-fMRI and activation likelihood estimation(ALE)meta-analysis.METHODS We performed a comprehensive literature search through July 12,2023,for studies investigating brain functional changes in adolescent MDD patients.We utilized regional homogeneity(ReHo),amplitude of low-frequency fluctuations(ALFF)and fractional ALFF(fALFF)analyses.We compared the regions of aberrant spontaneous neural activity in adolescents with MDD vs healthy controls(HCs)using ALE.RESULTS Ten studies(369 adolescent MDD patients and 313 HCs)were included.Combining the ReHo and ALFF/fALFF data,the results revealed that the activity in the right cuneus and left precuneus was lower in the adolescent MDD patients than in the HCs(voxel size:648 mm3,P<0.05),and no brain region exhibited increased activity.Based on the ALFF data,we found decreased activity in the right cuneus and left precuneus in adolescent MDD patients(voxel size:736 mm3,P<0.05),with no regions exhibiting increased activity.CONCLUSION Through ALE meta-analysis,we consistently identified the right cuneus and left precuneus as vulnerable brain regions in adolescent MDD patients,increasing our understanding of the neuropathology of affected adolescents.

Global Functional Network Connectivity Disturbances in Parkinson’s Disease with Mild Cognitive Impairment by Resting-State Functional MRI

Examining the spontaneous BOLD activity to understand the neural mechanism of Parkinson’s disease(PD)with mild cognitive impairment(MCI)is a focus in resting-state functional MRI(rs-fMRI)studies.This study aimed to investigate the alteration of brain functional connectivity in PD with MCI in a systematical way at two levels:functional connectivity analysis within resting state networks(RSNs)and functional network connectivity(FNC)analysis.Using group independent component analysis(ICA)on rs-fMRI data acquired from 30 participants(14 healthy controls and 16 PD patients with MCI),16 RSNs were identified,and functional connectivity analysis within the RSNs and FNC analysis were carried out between groups.Compared to controls,patients with PD showed decreased functional connectivity within putamen network,thalamus network,cerebellar network,attention network,and self-referential network,and increased functional connectivity within execution network.Globally disturbed,mostly increased functional connectivity of FNC was observed in PD group,and insular network and execution network were the dominant network with extensively increased functional connectivity with other RSNs.Cerebellar network showed decreased functional connectivity with caudate network,insular network,and self-referential network.In general,decreased functional connectivity within RSNs and globally disturbed,mostly increased functional connectivity of FNC may be characteristics of PD.Increased functional connectivity within execution network may be an early marker of PD.The multi-perspective study based on RSNs may be a valuable means to assess functional changes corresponding to specific RSN,contributing to the understanding of the neural mechanism of PD.

Modulatory effect of International standard Scalp Acupuncture on brain activation in the elderly as revealed by resting-state fMRI

The specific mechanisms by which acupuncture affects the central nervous system are unclear. In the International Standard Scalp Acupuncture system, acupuncture needles are applied at the middle line of the vertex, anterior parietal-temporal oblique line, and the posterior parietal-temporal oblique line. We conducted a single-arm prospective clinical trial in which seven healthy elderly volunteers (three men and four women;50–70 years old) received International Standard Scalp Acupuncture at MS5 (the mid-sagittal line between Baihui (DU20) and Qianding (DU21)), the left MS6 (line joining Sishencong (EX-HN1) and Xuanli (GB6)), and the left MS7 (line joining DU20 and Qubin (GB7)). After acupuncture, resting-state functional magnetic resonance imaging demonstrated changes in the fractional amplitude of low frequency fluctuations and regional homogeneity in various areas, showing remarkable enhancement of regional homogeneity in the bilateral anterior cingulate, left medial frontal gyrus, supramarginal gyrus, right middle frontal gyrus, and inferior frontal gyrus. Functional connectivity based on a seed region at the right middle frontal gyrus (42, 51, 9) decreased at the bilateral medial superior frontal gyrus. Our data preliminarily indicates that the international standard scalp acupuncture in healthy elderly participants specifcally enhances the correlation between the brain regions involved in cognition and implementation of the brain network regulation system and the surrounding adjacent brain regions. The study was approved by the Ethics Committee of the China-Japan Union Hospital at Jilin University, China, on July 18, 2016 (approval No. 2016ks043).

Brain activation and inhibition after acupuncture at Taichong and Taixi: resting-state functional magnetic resonance imaging

Acupuncture can induce changes in the brain. However, the majority of studies to date have focused on a single acupoint at a time. In the present study, we observed activity changes in the brains of healthy volunteers before and after acupuncture atTaichong （LR3） andTaixi （KI3） using resting-state functional magnetic resonance imaging. Fifteen healthy volunteers underwent resting-state functional magnetic resonance imaging of the brain 15 minutes before acupuncture, then received acupuncture atTaichong andTaixi using the nail-pressing needle insertion method, after which the needle was retained in place for 30 minutes. Fifteen minutes after withdrawal of the needle, the volunteers underwent a further session of resting-state functional magnetic res-onance imaging, which revealed that the amplitude of low-frequency lfuctuation, a measure of spontaneous neuronal activity, increased mainly in the cerebral occipital lobe and middle occipital gyrus （Brodmann area 18/19）, inferior occipital gyrus （Brodmann area 18） and cuneus （Brodmann area 18）, but decreased mainly in the gyrus rectus of the frontal lobe （Brodmann area 11）, inferi-or frontal gyrus （Brodmann area 44） and the center of the posterior lobe of the cerebellum. The present ifndings indicate that acupuncture atTaichong andTaixi speciifcally promote blood lfow and activation in the brain areas related to vision, emotion and cognition, and inhibit brain areas related to emotion, attention, phonological and semantic processing, and memory.

Resting-state network complexity and magnitude changes in neonates with severe hypoxic ischemic encephalopathy

Resting-state functional magnetic resonance imaging has revealed disrupted brain network connectivity in adults and teenagers with cerebral palsy. However, the specific brain networks implicated in neonatal cases remain poorly understood. In this study, we recruited 14 termborn infants with mild hypoxic ischemic encephalopathy and 14 term-born infants with severe hypoxic ischemic encephalopathy from Changzhou Children's Hospital, China. Resting-state functional magnetic resonance imaging data showed efficient small-world organization in whole-brain networks in both the mild and severe hypoxic ischemic encephalopathy groups. However, compared with the mild hypoxic ischemic encephalopathy group, the severe hypoxic ischemic encephalopathy group exhibited decreased local efficiency and a low clustering coefficient. The distribution of hub regions in the functional networks had fewer nodes in the severe hypoxic ischemic encephalopathy group compared with the mild hypoxic ischemic encephalopathy group. Moreover, nodal efficiency was reduced in the left rolandic operculum, left supramarginal gyrus, bilateral superior temporal gyrus, and right middle temporal gyrus. These results suggest that the topological structure of the resting state functional network in children with severe hypoxic ischemic encephalopathy is clearly distinct from that in children with mild hypoxic ischemic encephalopathy, and may be associated with impaired language, motion, and cognition. These data indicate that it may be possible to make early predictions regarding brain development in children with severe hypoxic ischemic encephalopathy, enabling early interventions targeting brain function. This study was approved by the Regional Ethics Review Boards of the Changzhou Children's Hospital(approval No. 2013-001) on January 31, 2013. Informed consent was obtained from the family members of the children. The trial was registered with the Chinese Clinical Trial Registry(registration number: ChiCTR1800016409) and the protocol version is 1.0.

The development of brain functional connectivity networks revealed by resting-state functional magnetic resonance imaging

Previous studies on brain functional connectivity networks in children have mainly focused on changes in function in specific brain regions, as opposed to whole brain connectivity in healthy children. By analyzing the independent components of activation and network connectivity between brain regions, we examined brain activity status and development trends in children aged 3 and 5 years. These data could provide a reference for brain function rehabilitation in children with illness or abnormal function. We acquired functional magnetic resonance images from 15 3-year-old children and 15 5-year-old children under natural sleep cond让ions. The participants were recruited from five kindergartens in the Nanshan District of Shenzhen City, China. The parents of the participants signed an informed consent form with the premise that they had been fully informed regarding the experimental protocol. We used masked independent component analysis and BrainNet Viewer software to explore the independent components of the brain and correlation connections between brain regions. We identified seven independent components in the two groups of children, including the executive control network, the dorsal attention network, the default mode network, the left frontoparietal network, the right frontoparietal network, the salience network, and the motor network. In the default mode network, the posterior cingulate cortex, medial frontal gyrus, and inferior parietal lobule were activated in both 3- and 5-year-old children, supporting the "three-brain region theory” of the default mode network. In the frontoparietal network, the frontal and parietal gyri were activated in the two groups of children, and functional connectivity was strengthened in 5-year-olds compared with 3-year-olds, although the nodes and network connections were not yet mature. The high-correlation network connections in the default mode networks and dorsal attention networks had been significantly strengthened in 5-year-olds vs. 3-year-olds. Further, the salience network in the 3-year-old children included an activated insula/inferior frontal gyrus-anterior cingulate cortex network circu让 and an activated thalamus-parahippocampal-posterior cingulate cortex-subcortical regions network circuit. By the age of 5 years, no des and high-correlation network connections (edges) were reduced in the salience network. Overall, activation of the dorsal attention network, default mode network, left frontoparietal network, and right frontoparietal network increased (the volume of activation increased, the signals strengthened, and the high-correlation connections increased and strengthened) in 5-year-olds compared with 3-year-olds, but activation in some brain nodes weakened or disappeared in the salience network, and the network connections (edges) were reduced. Between the ages of 3 and 5 years, we observed a tendency for function in some brain regions to be strengthened and for the generalization of activation to be reduced, indicating that specialization begins to develop at this time. The study protocol was approved by the local ethics committee of the Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences in China with approval No. SIAT-IRB- 131115-H0075 on November 15, 2013.

Resting-state connectivity in the default mode network and insula during experimental low back pain

Functional magnetic resonance imaging studies have shown that the insular cortex has a signif- icant role in pain identification and information integration, while the default mode network is associated with cognitive and memory-related aspects of pain perception. However, changes in the functional connectivity between the defauk mode network and insula during pain remain unclear. This study used 3.0 T functional magnetic resonance imaging scans in 12 healthy sub- jects aged 24.8 ± 3.3 years to compare the differences in the functional activity and connectivity of the insula and default mode network between the baseline and pain condition induced by intramuscular injection of hypertonic saline. Compared with the baseline, the insula was more functionally connected with the medial prefrontal and lateral temporal cortices, whereas there was lower connectivity with the posterior cingulate cortex, precuneus and inferior parietal lobule in the pain condition. In addition, compared with baseline, the anterior cingulate cortex exhibited greater connectivity with the posterior insula, but lower connectivity with the anterior insula, during the pain condition. These data indicate that experimental low back pain led to dysfunction in the connectivity between the insula and default mode network resulting from an impairment of the regions of the brain related to cognition and emotion, suggesting the impor- tance of the interaction between these regions in pain processing.

Human Mirror Neuron System (hMNS) Specific Differences in Resting-State Functional Connectivity in Self-Reported Democrats and Republicans: A Pilot Study

In light of ever-present partisan division in the US political system, it is critical that researchers gain a better under-standing of potential biological differences that exist between self-professed Democrats and Republicans. In the current pilot experiment, we examined differences within the human mirror neuron system (hMNS), a network linked to a host of social and emotional abilities, in a small group of self-identified Republicans and Democrats. We found clear differences between these two groups with respect to resting-state brain connectivity within the hMNS. These neural differences were not systematically related to differences in empathy. Our findings are consistent with the idea that other factors, such as one’s preferential type of social connectivity (broad vs. tight), may have driven the reported findings. These data provide novel insights regarding our knowledge of the biological basis of party identification, and suggest specific directions for future research.

Age-related connectivity differences between attention deficit and hyperactivity disorder patients and typically developing subjects：a resting-state functional MRI study

Attention deficit and hyperactivity disorder（ADHD） is a disorder characterized by behavioral symptoms including hyperactivity/impulsivity among children,adolescents,and adults.These ADHD related symptoms are influenced by the complex interaction of brain networks which were under explored.We explored age-related brain network differences between ADHD patients and typically developing（TD） subjects using resting state f MRI（rs-f MRI） for three age groups of children,adolescents,and adults.We collected rs-f MRI data from 184 individuals（27 ADHD children and 31 TD children;32 ADHD adolescents and 32 TD adolescents;and 31 ADHD adults and 31 TD adults）.The Brainnetome Atlas was used to define nodes in the network analysis.We compared three age groups of ADHD and TD subjects to identify the distinct regions that could explain age-related brain network differences based on degree centrality,a well-known measure of nodal centrality.The left middle temporal gyrus showed significant interaction effects between disease status（i.e.,ADHD or TD） and age（i.e.,child,adolescent,or adult）（P 0.001）.Additional regions were identified at a relaxed threshold（P 0.05）.Many of the identified regions（the left inferior frontal gyrus,the left middle temporal gyrus,and the left insular gyrus） were related to cognitive function.The results of our study suggest that aberrant development in cognitive brain regions might be associated with age-related brain network changes in ADHD patients.These findings contribute to better understand how brain function influences the symptoms of ADHD.

Effect and cerebral mechanism of moxibustion at heat-sensitized Yaoyangguan(GV3)in patients with lumbar disc herniation and myofascial pain syndrome by resting-state functionality magnetic resonance imaging:protocol for an observational study

We want to explore the analgesic brain effect of the moxibustion at heat-sensitized Yaoyangguan(GV3)in patients with lumbar disc herniation(LDH)and myofascial pain syndrome(MPS).In an assessor-blinded observational study,we will include 15 LDH and 15 MPS.They will accept same treatment of heat-sensitive moxibustion at Yaoyangguan(GV3).The resting-state functionality magnetic resonance imaging image data of brain activities before and after treatment will be analyzed by mean fractional amplitude of low-frequency fluctuation,regional homogeneity analysis and brain functional connection.We select seed of first sensory cortex,second sensory cortex,insula cortex,periaqueductal gray and anterior cingulate cortex as the regions of interest to analyse the relationship between brain functional connectivity of pain-related networks and clinical data.Our study could disclose key brain targets and central response characteristics of the analgesic brain effect and the brain functional connection of heat-sensitive moxibustion.

The altered network complexity of resting-state functional brain activity in schizophrenia and bipolar disorder patients

Schizophrenia(SZ)and bipolar disorder(BD)are two of themost frequent mental disorders.These disorders exhibit similarpsychotic symptoms,making diagnosis challenging and leadingto misdiagnosis.Yet,the network complexity changes drivingspontaneous brain activity in SZ and BD patients are still unknown.Functional entropy(FE)is a novel way of measuring the dispersion(or spread)of functional connectivities inside the brain.The FE wasutilized in this study to examine the network complexity of the resting-state fMRI data of SZ and BD patients at three levels,including global,modules,and nodes.At three levels,the FE of SZand BD patients was considerably lower than that of normal control(NC).At the intra-module level,the FE of SZ was substantially higher than that of BD in the cingulo-opercular network.Moreover,a strong negative association between FE and clinical measureswas discovered in patient groups.Finally,we classified using theFE features and attained an accuracy of 66.7%(BD vs.SZ vs.NC)and an accuracy of 75.0%(SZ vs.BD).These findings proposed that network connectivity’s complexity analyses using FE can provideimportant insights for the diagnosis of mental illness.

Resting-state functional connectivity in lifelong musicians

Background:It has been postulated that musicianship can lead to enhanced brain and cognitive reserve,but the neural mechanisms of this effect have been poorly understood.Lifelong professional musicianship in conjunction with novel brain imaging techniques offers a unique opportunity to examine brain network differences between musicians and matched controls.Objective:In this study we aim to investigate how resting-state functional networks(FNs)manifest in lifelong active musicians.We will evaluate the FNs of lifelong musicians and matched healthy controls using resting-state functional magnetic resonance imaging.Methods:We derive FNs using the data-driven independent component analysis approach and analyze the functional network con-nectivity(FNC)between the default mode(DMN),sensory-motor(SMN),visual(VSN),and auditory(AUN)networks.We examine whether the linear regressions between FNC and age are different between the musicians and the control group.Results:The age trajectory of average FNC across all six pairs of FNs shows significant differences between musicians and controls.Musicians show an increase in average FNC with age while controls show a decrease(P=0.013).When we evaluated each pair of FN,we note that in musicians FNC values increased with age in DMN–AUN,DMN–VSN,and SMN–VSN and in controls FNC values decreased with age in DMN–AUN,DMN–SMN,AUN–SMN,and SMN–VSN.Conclusion:This result provides early evidence that lifelong musicianship may contribute to enhanced brain and cognitive reserve.Results of this study are preliminary and need to be replicated with a larger number of participants.

Regional superficial amygdala resting-state functional connectivity in adults infers childhood maltreatment severity

Background:Childhood maltreatment(CM)is a potential risk factor for some neuropsychiatric disorders in adulthood(e.g.depression and anxiety)and alters trajectories of brain development.Accumulating evidence suggests that functional connectivity of the limbic system,especially the amygdala,is highly associated with childhood maltreatment,although not all studies have found this.These inconsistent results may be due to differential alterations of amygdala resting-state functional connectivity(rsFC)following childhood maltreatment.Objective:Our aim was to investigate the relationship between the rsFC of amygdala subregions and CM severity,as well as to develop a stable rsFC-based model for inferring the severity of CM.Methods:In this study,we employed the Childhood Trauma Questionnaire(CTQ)to assess CM severity in each individual.We explored the relationship between the rsFC of amygdala subregions(i.e.centromedial-CMA,basolateral-BLA,superficial-SFA amygdala)and CM experience in a discovery dataset of n=110 healthy Chinese participants by linear multiple regression analysis.Subsequent dimensional and categorical approach were performed to elucidate the relationship between rsFCs and CM severity and CM subtypes,respectively.A support vector regression model was then conducted to validate the associations between rsFCs and total CTQ scores.Moreover,we also verified the model into another independent replication dataset(n=38).Results:Our findings suggested that childhood maltreatment was negatively associated with rsFC between the right superficial amyg-dala and perigenual anterior cingulate cortex(pgACC)/postcentral gyrus(PCG)but not the other two amygdala subregions.Moreover,SFA-pgACC coupling was more associated with physical neglect whereas the SFA-PCG was more related to emotional neglect.In addi-tion,supervised machine learning confirmed that using these two rsFCs as predictors could stably estimate continuous maltreatment severity in both discovery and replication datasets.Conclusion:The current study supports that the rsFCs of superficial amygdala are related to childhood maltreatment and which may be a potential biomarker for the effects of childhood maltreatment-related psychiatric disorders(i.e.depression and anxiety).

Personality–brain connection:Based on resting-state functional magnetic resonance imaging data-driven exploration

Background:The personality-brain association mechanism has been a topic of interest in the field of neuroscience.Usually,the previous research strategy was to first group the population based on different personality traits,and then explore the brain mechanisms corresponding to different personality groups.At present,a“brain-first”research strategy,which uses data-driven approaches instead of personality traits to first group the population,has been adopted to further enhance study objectivity.Methods:Here,we used a data-driven approach following the“brain-first”research strategy to deeply mine the resting-state brain functional magnetic resonance imaging data of 119 healthy participants,classified subjects into different groups based on brain image characteristics,and used the Sixteen Personality Factor Questionnaire to explain the variabilities of resting-state brain characteristics between different groups.Results:We have identified 3 personality–brain connections,including the privateness–left frontoparietal network,liveliness–sensory–motor network,and vigilance–sensory–motor network.Conclusion:We conclude that the above-mentioned three personality factors are based on brain neural activity,independent of the subjective experience of the personality scale creator,and have stronger explanatory power of brain imaging features.

RESTplus: an improved toolkit for resting-state functional magnetic resonance imaging data processing

Resting-state functional magnetic resonance imaging (RS-fMRI)[1,2] provides relatively high spatial and temporal resolution for mapping spontaneous brain activity non-invasively. It has been widely used in cognitive neuroscience and clinical studies. A number of comprehensive software packages have been developed for RS-fMRI data analysis, among which a MATLAB package named REST (RESing-state fMRI data analysis Toolkit, released in October 2008 at http://www.restfmri.net)[3] is the earliest one dedicated to RS-fMRI analysis. REST focuses on RS-fMRI postprocessing metrics.

Acupuncture Treatment Modulates the Resting-State Functional Connectivity of Brain Regions in Migraine Patients without Aura

Objective： To investigate the modulatory effect of acupuncture treatment on the resting-state functional connectivity of brain regions in migraine without aura （MWoA） patients. Methods： Twelve MWoA patients were treated with standard acupuncture treatment for 4 weeks. All MWoA patients received resting-state functional magnetic resonance imaging （fMRI） scanning before and after acupuncture treatment. Another 12 normal subjects matched in age and gender were recruited to serve as healthy controls. The changes of resting- state functional connectivity in MWoA patients before and after the acupuncture treatment and those with the healthy controls were compared. Results： Before acupuncture treatment, the MWoA patients had significantly decreased functional connectivity in certain brain regions within the frontal and temporal lobe when compared with the healthy controls. After acupuncture treatment, brain regions showing decreased functional connectivity revealed significant reduction in MWoA patients compared with before acupuncture treatment. Conclusions： Acupuncture treatment could increase the functional connectivity of brain regions in the intrinsic decreased brain networks in MWoA patients. The results provided further insights into the interpretation of neural mechanisms of acupuncture treatment for migraine.

Abnormal function of the posterior cingulate cortex in heroin addicted users during resting-state and drug-cue stimulation task

Background Previous animal and neuroimaging studies have demonstrated that brain function in heroin addicted users is impaired. However, the posterior cingulate cortex （PCC） has not received much attention. The purpose of this study was to investigate whether chronic heroin use is associated with craving-related changes in the functional connectivity of the PCC of heroin addicted users. Methods Fourteen male adult chronic heroin users and fifteen age and gender-matched healthy subjects participated in the present study. The participants underwent a resting-state functional magnetic resonance imaging （fMRI） scan and a cue-induced craving task fMRI scan. The activated PCC was identified in the cue-induced craving task by means of a group contrast test. Functional connectivity was analyzed based on resting-state fMRI data in order to determine the correlation between brain regions. The relationship between the connectivity of specific regions and heroin dependence was investigated. Results The activation of PCC, bilateral anterior cingulate cortex, caudate, putamen, precuneus, and thalamus was significant in the heroin group compared to the healthy group in the cue-induced craving task. The detectable functional connectivity of the heroin users was stronger between the PCC and bilateral insula, bilateral dorsal striatum, right inferior parietal Iobule （IPL） and right supramarginal gyrus （P 〈0.001） compared to that of the healthy subjects in the resting-state data analysis. The strength of the functional connectivity, both for the PCC-insula （r=0.60, P 〈0.05） and for PCC-striatum （t=0.58, P 〈0.05）, was positively correlated with the duration of heroin use. Conclusion The altered functional connectivity patterns in the PCC-insula and PCC-striatum areas may be regarded as biomarkers of brain damage severity in chronic heroin users.

Resting-state fMRI studies in epilepsy

Epilepsy is a disease characterized by abnormal spontaneous activity in the brain.Resting-state functional magnetic resonance imaging（RS-fMRI） is a powerful technique for exploring this activity.With good spatial and temporal resolution,RS-fMRI is a promising approach for accurate localization of the focus of seizure activity.Although simultaneous electroencephalogram-fMRI has been performed with patients in the resting state,most studies focused on activation.This mini-review focuses on RS-fMRI alone,including its computational methods and its application to epilepsy.

Dopamine D4 Receptor Gene Associated with the Frontal-Striatal-Cerebellar Loop in Children with ADHD: A Resting-State fMRI Study

Attention deficit hyperactivity disorder（ADHD）is a common childhood neuropsychiatric disorder that has been linked to the dopaminergic system. This study aimed to investigate the effects of regulation of the dopamine D4 receptor（DRD4） on functional brain activity during the resting state in ADHD children using the methods of regional homogeneity（Re Ho） and functional connectivity（FC）. Resting-state functional magnetic resonance imaging data were analyzed in 49 children with ADHD. All participants were classified as either carriers of the DRD44-repeat/4-repeat（4 R/4 R） allele（n = 30） or the DRD42-repeat（2 R） allele（n = 19）. The results showed that participants with the DRD4 2 R allele had decreased Re Ho bilaterally in the posterior lobes of the cerebellum, while Re Ho was increased in the left angular gyrus. Compared with participants carrying the DRD4 4 R/4 R allele, those with the DRD4 2 R allele showed decreased FC to the left angular gyrus in the left striatum, right inferior frontal gyrus, and bilateral lobes of the cerebellum. The increased FC regions included the left superior frontal gyrus, medial frontal gyrus, and rectus gyrus. These data suggest that the DRD4 polymorphisms are associated with localized brain activity and specific functional connections, including abnormality in the frontal-striatal-cerebellar loop. Our study not only enhances the understanding of the correlation between the cerebellar lobes and ADHD, but also provides an imaging basis for explaining the neural mechanisms underlying ADHD in children.

Altered regional homogeneity in post-traumatic stress disorder: a resting-state functional magnetic resonance imaging study

Objective Little is known about the brain systems that contribute to vulnerability to post-traumatic stress disorder （PTSD）. Comparison of the resting-state patterns of intrinsic functional synchronization, as measured by functional magnetic resonance imaging （fMRI）, between groups with and without PTSD following a traumatic event can help identify the neural mechanisms of the disorder and targets for intervention. Methods Fifty-four PTSD patients and 72 matched traumatized subjects who experienced the 2008 Sichuan earthquake were imaged with blood oxygen level-dependent （BOLD） fMRI and analyzed using the measure of regional homogeneity （ReHo） during the resting state. Results PTSD patients presented enhanced ReHo in the left inferior parietal lobule and right superior frontal gyrus, and reduced ReHo in the right middle temporal gyrus and lingual gyrus, relative to traumatized individuals without PTSD. Conclusion Our findings showed that abnormal brain activity exists under resting conditions in PTSD patients who had been exposed to a major earthquake. Alterations in the local functional connectivity of cortical regions are likely to contribute to the neural mechanisms underlying PTSD.