Thalamic Functional Connectivity Research Articles

Functional connectivity alterations in the thalamus among patients with bronchial asthma.

Bronchial Asthma (BA) is a common chronic respiratory disease worldwide. Earlier research has demonstrated abnormal functional connectivity (FC) in multiple cognition-related cortices in asthma patients. The thalamus (Thal) serves as a relay center for transmitting sensory signals, yet the modifications in the thalamic FC among individuals with asthma remain uncertain. This research employed the resting-state functional connectivity (rsFC) approach to explore alterations in thalamic functional connectivity among individuals with BA. After excluding participants who did not meet the criteria, this study finally included 31 patients with BA, with a gender distribution of 16 males and 15 females. Subsequently, we recruited 31 healthy control participants (HC) matched for age, gender, and educational background. All participants underwent the Montreal Cognitive Assessment (MoCA) and the Hamilton Depression Rating Scale (HAMD) assessment. Following this, both groups underwent head magnetic resonance imaging scans, and resting-state functional magnetic resonance imaging (rs-fMRI) data was collected. Based on the AAL (Automated Anatomical Labeling) template, the bilateral thalamic regions were used as seed points (ROI) for subsequent rsFC research. Pearson correlation analysis was used to explore the relationship between thalamic functional connectivity and neuropsychological scales in both groups. After controlling for potential confounding factors such as age, gender, intelligence, and emotional level, a two-sample t-test was further used to explore differences in thalamic functional connectivity between the two groups of participants. Compared to the HC group, the BA group demonstrated heightened functional connectivity (FC) between the left thalamus and the left cerebellar posterior lobe (CPL), left postcentral gyrus (PCG), and right superior frontal gyrus (SFG). Concurrently, there was a decrease in FC with both the Lentiform Nucleus (LN) and the left corpus callosum (CC). Performing FC analysis with the right thalamus as the Region of Interest (ROI) revealed an increase in FC between the right thalamus and the right SFG as well as the left CPL. Conversely, a decrease in FC was observed between the right thalamus and the right LN as well as the left CC. In our study, we have verified the presence of aberrant FC patterns in the thalamus of BA patients. When compared to HCs, BA patients exhibit aberrant alterations in FC between the thalamus and various brain areas connected to vision, hearing, emotional regulation, cognitive control, somatic sensations, and wakefulness. This provides further confirmation of the substantial role played by the thalamus in the advancement of BA.

Subregional thalamic functional connectivity abnormalities and cognitive impairments in first-episode schizophrenia

BackgroundPrevious studies have documented thalamic functional connectivity (FC) abnormalities in schizophrenia, typically examining the thalamus as a whole. The specific link between subregional thalamic FC and cognitive deficits in first-episode schizophrenia (FES) remains unexplored. MethodsUsing data from resting-state functional magnetic resonance imaging, we compared whole-brain FC with thalamic subregions between patients and HCs, and analyzed FC changes in drug-naïve patients separately. We then examined correlations between FC abnormalities with both cognitive impairment and clinical symptoms. ResultsA total of 33 FES patients (20 drug-naïve) and 32 age- and sex-matched healthy controls (HCs) were included. Compared to HCs, FES patients exhibited increased FC between specific thalamic subregions and cortical regions, particularly bilateral middle temporal lobe and cuneus gyrus, left medial superior frontal gyrus, and right inferior/superior occipital gyrus. Decreased FC was observed between certain thalamic subregions and the left inferior frontal triangle. These findings were largely consistent in drug-naïve patients. Notably, deficits in social cognition and visual learning in FES patients correlated with increased FC between certain thalamic subregions and cortical regions involving the right superior occipital gyrus and cuneus gyrus. The severity of negative symptoms was associated with increased FC between a thalamic subregion and the left middle temporal gyrus. ConclusionOur findings suggest FC abnormalities between thalamic subregions and cortical areas in FES patients. Increased FC correlated with cognitive deficits and negative symptoms, highlighting the importance of thalamo-cortical connectivity in the pathophysiology of schizophrenia.

Abnormal functional connectivity of the occipital thalamus with the superior occipital gyrus is associated with mild cognitive impairment in elderly individuals with primary insomnia

AbstractStudy objectivesPrimary insomnia (PI) triggers a decline in cognitive function, and the thalamus plays an integral role in this process; however, the mechanisms are unclear. The purpose of this study was to investigate the altered functional connectivity (FC) of the thalamus in PI patients with mild cognitive impairment (MCI) and to explore the potential neural mechanisms of thalamic involvement in these patients.MethodsThis case–control study was conducted in older adults from various communities in Fuzhou, China with a PI diagnosis. These participants underwent neuropsychological assessment and were matched in a 1:2 ratio to the healthy control (HC) group and the PI group according to sex, age, and education level. Resting‐state functional magnetic resonance imaging was used to explore changes in thalamic FC in PI patients. To further compare changes in thalamic and whole‐brain FC, we further divided the PI group into cognitively normal patients and patients with MCI according to the diagnostic criteria for MCI. The relationship between abnormal FC and cognitive function was investigated.ResultsThe 28 HCs and 58 participants with PI showed significant differences in Montreal Cognitive Assessment (MoCA) scores (p = .044). In comparison to the HC group, the PI group showed enhanced FC of the occipital thalamus with the left inferior occipital gyrus, right lingual gyrus, left middle temporal gyrus, left superior marginal gyrus, left dorsolateral superior frontal gyrus, and right anterior central gyrus. The MoCA total score and the executive function, attention, and abstraction scores of PI patients with MCI (PI–MCI) were worse than those of PI patients without MCI. In comparison to the simple PI group, FC was enhanced in the PI–MCI group between the left occipital thalamus and the middle occipital gyrus, and between the right occipital thalamus and the right superior frontal gyrus, left middle frontal gyrus, right superior occipital gyrus, and orbital inferior frontal gyrus. There was a significant negative correlation between the MoCA total score and the enhanced FC between the right occipital thalamus and right superior occipital gyrus (r = −.419, p = .042).ConclusionThe early onset of cognitive impairment in patients with PI is associated with altered FC between the thalamus and the cortex. Enhanced FC between the thalamus and the visual cortex, that is, the superior occipital gyrus, which is involved in attentional processing, may play a role in the early onset of cognitive impairment in insomnia patients. Moreover, due to the fact that PI patients “overdraw” the compensatory capacity of these brain regions earlier, the PI–MCI may fall into the abyss of “decompensation” faster and face more severe cognitive impairments.

Altered thalamic volumes and functional connectivity in the recovered patients with psychosis

BackgroundInvestigating neural correlates in recovered patients with psychosis is important in terms of identifying biological markers associated with recovery status or predicting a possible future relapse. We sought to examine thalamic nuclei volumes and thalamus-centered functional connectivity (FC) in recovered patients with psychosis who discontinued their medication. MethodsThirty patients with psychosis who satisfied the criteria for full recovery and 50 healthy controls (HC) matched for age, sex, and education underwent magnetic resonance imaging and clinical evaluation. The recovered patients were divided into the maintained and relapsed subjects according to their clinical status on the follow-ups. Thalamic nuclei volumes and thalamus-centered FC were measured between the recovered patients and HC. Correlations between the thalamic nuclei or altered FC, and clinical symptoms and cognitive functioning were explored. ResultsModest cognitive impairments and reduced thalamic nuclei volumes were evident in the recovered patients. Moreover, we found altered thalamo-cortical connectivity and its associations with negative symptoms and cognitive functioning in the recovered patients compared with HC. ConclusionThese findings suggest that there are still cognitive impairments, and aberrant neuronal changes in the recovered patients. The implication of differential FC patterns between the maintained and the relapsed patients remain to be further explored.

Thalamic functional connectivity and sensorimotor processing in neurodevelopmental disorders.

One of the earliest neurobiological findings in autism has been the differences in the thalamocortical pathway connectivity, suggesting the vital role thalamus plays in human experience. The present functional MRI study investigated resting-state functional connectivity of the thalamus in 49 (autistic, ADHD, and neurotypical) young adults. All participants underwent structural MRI and eyes-open resting state functional MRI scans. After preprocessing the imaging data using Conn's connectivity toolbox, a seed-based functional connectivity analysis was conducted using bilateral thalamus as primary seeds. Autistic participants showed stronger thalamic connectivity, relative to ADHD and neurotypical participants, between the right thalamus and right precentral gyrus, right pars opercularis-BA44, right postcentral gyrus, and the right superior parietal lobule (RSPL). Autistic participants also showed significantly increased connectivity between the left thalamus and the right precentral gyrus. Furthermore, regression analyses revealed a significant relationship between autistic traits and left thalamic-precentral connectivity (R2 = 0.1113), as well as between autistic traits and right postcentral gyrus and RSPL connectivity (R2 = 0.1204) in autistic participants compared to ADHD. These findings provide significant insights into the role of thalamus in coordinating neural information processing and its alterations in neurodevelopmental disorders.

Thalamic Contributions to Functional Circuitry in Preclinical Alzheimer’s Disease

AbstractBackgroundThalamic nuclei are heterogeneously impacted by Alzheimer’s disease (AD) pathology. The anterior thalamus shows tau deposition early on in AD, while other nuclei, such as the mediodorsal (MD) thalamus are spared by tau until much later in the disease process (Braak and Braak, 1991). Furthermore, anterior and MD thalamus have dissociable roles in memory performance – the anterior has a greater role in recollective memory, while the MD plays a role in familiarity. Additionally, the anterior thalamus has direct anatomical links to brain regions implicated in poor short‐term memory performance in AD, while MD thalamus connectivity is primarily to regions spared of AD pathology until late. We sought to identify differences in functional connectivity between the anterior and MD thalamus in amyloid negative and positive individuals.MethodWe examined resting‐state functional MRI data from the A4 study (n = 569), including 254 healthy controls and 315 individuals with preclinical AD based on amyloid SUVR>1.14 (Table 1). We assessed functional connectivity of anterior and MD thalamus to the whole brain using 2mm radius spherical seeds at the center of mass of Morel atlas nuclei. All results were covaried for age, sex, handedness, and years of education.ResultsAnterior thalamic activity was positively correlated with parahippocampal gyrus, fusiform, and insula, and negatively with the striatum and thalamus. MD thalamic activity was positively correlated with the amygdala, ventral striatum, and anterior cingulate, and negatively correlated to the superior temporal gyrus and regions of the parieto‐occipital lobe. In preclinical AD, compared with HCs, the positive correlations in either thalamic nuclei were lost.ConclusionThe thalamic functional connectivity observed agrees with preexisting literature dissociating structures related to the anterior and MD thalamus. Our results provide a basis for further exploration of thalamic nuclei to AD‐involved functional networks, as well as future analysis of the observed connectivity measures to cognition.

Thalamic Contributions to Functional Circuitry in Preclinical Alzheimer’s Disease

AbstractBackgroundThalamic nuclei are heterogeneously impacted by Alzheimer’s disease (AD) pathology. The anterior thalamus shows tau deposition early on in AD, while other nuclei, such as the mediodorsal (MD) thalamus are spared by tau until much later in the disease process (Braak and Braak, 1991). Furthermore, anterior and MD thalamus have dissociable roles in memory performance – the anterior has a greater role in recollective memory, while the MD plays a role in familiarity. Additionally, the anterior thalamus has direct anatomical links to brain regions implicated in poor short‐term memory performance in AD, while MD thalamus connectivity is primarily to regions spared of AD pathology until late. We sought to identify differences in functional connectivity between the anterior and MD thalamus in amyloid negative and positive individuals.MethodWe examined resting‐state functional MRI data from the A4 study (n = 569), including 254 healthy controls and 315 individuals with preclinical AD based on amyloid SUVR>1.14 (Table 1). We assessed functional connectivity of anterior and MD thalamus to the whole brain using 2mm radius spherical seeds at the center of mass of Morel atlas nuclei. All results were covaried for age, sex, handedness, and years of education.ResultAnterior thalamic activity was positively correlated with parahippocampal gyrus, fusiform, and insula, and negatively with the striatum and thalamus. MD thalamic activity was positively correlated with the amygdala, ventral striatum, and anterior cingulate, and negatively correlated to the superior temporal gyrus and regions of the parieto‐occipital lobe. In preclinical AD, compared with HCs, the positive correlations in either thalamic nuclei were lost.ConclusionThe thalamic functional connectivity observed agrees with preexisting literature dissociating structures related to the anterior and MD thalamus. Our results provide a basis for further exploration of thalamic nuclei to AD‐involved functional networks, as well as future analysis of the observed connectivity measures to cognition.

The role of the thalamic subregions in major depressive disorder with childhood maltreatment: Evidences from dynamic and static functional connectivity

BackgroundMajor depressive disorder (MDD) with a history of childhood maltreatment represents a highly prevalent clinical phenotype. Previous studies have demonstrated functional alterations of the thalamus among MDD. However, no study has investigated the static and dynamic changes in functional connectivity (FC) within thalamic subregions among MDD with childhood maltreatment. MethodsThis study included four groups: MDD with childhood maltreatment (n = 48), MDD without childhood maltreatment (n = 30), healthy controls with childhood maltreatment (n = 57), and healthy controls without childhood maltreatment (n = 46). Sixteen thalamic subregions were selected as seed to investigate group-differences in dynamic FC (dFC) and static FC (sFC). Correlation analyses were performed to assess the associations between abnormal FC and maltreatment severity. Eventually, moderation analyses were employed to explore the moderating role of abnormal FC in the relationship between maltreatment and depressive severity. ResultsMDD with childhood maltreatment exhibit abnormal thalamic subregions FC compared to MDD without childhood maltreatment, characterized by abnormalities with the sFC of the rostral anterior cingulate cortex, with the dFC of the calcarine, middle cingulate cortex, precuneus cortex and superior temporal gyrus. Furthermore, sFC with the rostral anterior cingulate cortex and dFC with the middle cingulate cortex were correlated with the severity of maltreatment. Additionally, dFC with the superior temporal gyrus moderates the relationship between maltreatment and depression severity. LimitationsThe cross-sectional designs fail to infer causality. ConclusionsOur findings support thalamic dysfunction as neurobiological features of childhood maltreatment as well as vulnerability to MDD.

Thalamic network under wakefulness after sleep onset and its coupling with daytime fatigue in insomnia disorder: An EEG-fMRI study

BackgroundFatigue is the most common daytime impairment of insomnia disorder (ID). Thalamus is acknowledged as the key brain region closely associated with fatigue. However, the thalamus-based neurobiological mechanisms of fatigue in patients with ID remain unknown. MethodsForty-two ID patients and twenty-eight well-matched healthy controls (HCs) underwent simultaneous electroencephalography––functional magnetic resonance imaging. We calculated the functional connectivity (FC) between the thalamic seed and each voxel across the whole brain in two conditions of wakefulness––after sleep onset (WASO) and before sleep onset. A linear mixed effect model was used to determine the condition effect of the thalamic FC. The correlation between daytime fatigue and the thalamic connectivity was explored. ResultsAfter sleep onset, the connectivity with the bilateral thalamus was increased in the cerebellar and cortical regions. Compared with HCs, ID patients showed significantly lower FC between left thalamus and left cerebellum under the WASO condition. Furthermore, thalamic connectivity with cerebellum under the WASO condition was negatively correlated with Fatigue Severity Scale scores in the pooled sample. ConclusionsThese findings contribute to an emerging framework that reveals the link between insomnia-related daytime fatigue and the altered thalamic network after sleep onset, further highlighting the possibility that this neural pathway is a therapeutic target for meaningfully mitigating fatigue.

Abnormal Thalamic Functional Connectivity Correlates With Cardiorespiratory Fitness and Physical Activity in Progressive Multiple Sclerosis (P12-8.011)

Abnormal Thalamic Functional Connectivity Correlates With Cardiorespiratory Fitness and Physical Activity in Progressive Multiple Sclerosis (P12-8.011)

Associations between thalamocortical functional connectivity and sensory over-responsivity in infants at high likelihood for ASD.

Despite growing evidence implicating thalamic functional connectivity atypicalities in autism spectrum disorder (ASD), it remains unclear how such alterations emerge early in human development. Because the thalamus plays a critical role in sensory processing and neocortical organization early in life, its connectivity with other cortical regions could be key for studying the early onset of core ASD symptoms. Here, we investigated emerging thalamocortical functional connectivity in infants at high (HL) and typical (TL) familial likelihood for ASD in early and late infancy. We report significant thalamo-limbic hyperconnectivity in 1.5-month-old HL infants, and thalamo-cortical hypoconnectivity in prefrontal and motor regions in 9-month-old HL infants. Importantly, early sensory over-responsivity (SOR) symptoms in HL infants predicted a direct trade-off in thalamic connectivity whereby stronger thalamic connectivity with primary sensory regions and basal ganglia was inversely related to connectivity with higher order cortices. This trade-off suggests that ASD may be characterized by early differences in thalamic gating. The patterns reported here could directly underlie atypical sensory processing and attention to social vs. nonsocial stimuli observed in ASD. These findings lend support to a theoretical framework of ASD whereby early disruptions in sensorimotor processing and attentional biases early in life may cascade into core ASD symptomatology.

Using support vector machine to explore the difference of function connection between deficit and non-deficit schizophrenia based on gray matter volume.

Schizophrenia can be divided into deficient schizophrenia (DS) and non-deficient schizophrenia (NDS) according to the presence of primary and persistent negative symptoms. So far, there are few studies that have explored the differences in functional connectivity (FC) between the different subtypes based on the region of interest (ROI) from GMV (Gray matter volume), especially since the characteristics of brain networks are still unknown. This study aimed to investigate the alterations of functional connectivity between DS and NDS based on the ROI obtained by machine learning algorithms and differential GMV. Then, the relationships between the alterations and the clinical symptoms were analyzed. In addition, the thalamic functional connection imbalance in the two groups was further explored. A total of 16 DS, 31 NDS, and 38 health controls (HC) underwent resting-state fMRI scans, patient group will further be evaluated by clinical scales including the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Negative Symptoms (SANS), and the Scale for the Assessment of Positive Symptoms (SAPS). Based on GMV image data, a support vector machine (SVM) is used to classify DS and NDS. Brain regions with high weight in the classification were used as seed points in whole-brain FC analysis and thalamic FC imbalance analysis. Finally, partial correlation analysis explored the relationships between altered FC and clinical scale in the two subtypes. The relatively high classification accuracy is obtained based on the SVM. Compared to HC, the FC increased between the right inferior parietal lobule (IPL.R) bilateral thalamus, and lingual gyrus, and between the right inferior temporal gyrus (ITG.R) and the Salience Network (SN) in NDS. The FC between the right thalamus (THA.R) and Visual network (VN), between ITG.R and right superior occipital gyrus in the DS group was higher than that in HC. Furthermore, compared with NDS, the FC between the ITG.R and the left superior and middle frontal gyrus decreased in the DS group. The thalamic FC imbalance, which is characterized by frontotemporal-THA.R hypoconnectivity and sensory motor network (SMN)-THA.R hyperconnectivity was found in both subtypes. The FC value of THA.R and SMN was negatively correlated with the SANS score in the DS group but positively correlated with the SAPS score in the NDS group. Using an SVM classification method and based on an ROI from GMV, we highlighted the difference in functional connectivity between DS and NDS from the local to the brain network, which provides new information for exploring the neural physiopathology of the two subtypes of schizophrenic.

Abnormal thalamic functional connectivity correlates with cardiorespiratory fitness and physical activity in progressive multiple sclerosis.

Altered thalamic volumes and resting state (RS) functional connectivity (FC) might be associated with physical activity (PA) and cardiorespiratory fitness (CRF) in people with progressive multiple sclerosis (PMS). To assess thalamic structural and functional alterations and investigate their correlations with PA/CRF levels in people with PMS. Seven-day accelerometry and cardiopulmonary exercise testing were used to assess PA/CRF levels in 91 persons with PMS. They underwent 3.0T structural and RS fMRI acquisition with 37 age/sex-matched healthy controls (HC). Between-group comparisons of MRI measures and their correlations with PA/CRF variables were assessed. PMS people had lower volumes compared to HC (all p < 0.001). At corrected threshold, PMS showed decreased intra- and inter-thalamic RS FC, and increased RS FC between the thalamus and the hippocampus, bilaterally. At uncorrected threshold, decreased thalamic RS FC with caudate nucleus, cerebellum and anterior cingulate cortex (ACC), as well as increased thalamic RS FC with occipital regions, were also detected. Lower CRF, measured as peak oxygen consumption (VO2peak), correlated with lower white matter volume (r = 0.31, p = 0.03). Moreover, lower levels of light PA correlated with increased thalamic RS FC with the right hippocampus (r = -0.3, p = 0.05). People with PMS showed widespread brain atrophy, as well as pronounced intra-thalamic and thalamo-hippocampal RS FC abnormalities. White matter atrophy correlated with CRF, while increased thalamo-hippocampal RS FC was associated to worse PA levels. Thalamic RS FC might be used to monitor physical impairment and efficacy of rehabilitative and disease-modifying treatments in future studies.

Acute thalamic connectivity precedes chronic post-concussive symptoms in mild traumatic brain injury.

Chronic post-concussive symptoms are common after mild traumatic brain injury (mTBI) and are difficult to predict or treat. Thalamic functional integrity is particularly vulnerable in mTBI and may be related to long-term outcomes but requires further investigation. We compared structural MRI and resting state functional MRI in 108 patients with a Glasgow Coma Scale (GCS) of 13-15 and normal CT, and 76 controls. We examined whether acute changes in thalamic functional connectivity were early markers for persistent symptoms and explored neurochemical associations of our findings using PET data. Of the mTBI cohort, 47% showed incomplete recovery 6 months post-injury. Despite the absence of structural changes, we found acute thalamic hyperconnectivity in mTBI, with specific vulnerabilities of individual thalamic nuclei. Acute fMRI markers differentiated those with chronic post-concussive symptoms, with time- and outcome-dependent relationships in a sub-cohort followed longitudinally. Moreover, emotional and cognitive symptoms were associated with changes in thalamic functional connectivity to known serotonergic and noradrenergic targets, respectively. Our findings suggest that chronic symptoms can have a basis in early thalamic pathophysiology. This may aid identification of patients at risk of chronic post-concussive symptoms following mTBI, provide a basis for development of new therapies and facilitate precision medicine application of these therapies.

Galvanic vestibular stimulation modulates altered thalamic and basal ganglia functional connectivity in Parkinson’s disease

Galvanic vestibular stimulation modulates altered thalamic and basal ganglia functional connectivity in Parkinson’s disease

Thalamic volume and functional connectivity are associated with nicotine dependence severity and craving.

Tobacco smoking is associated with deleterious health outcomes. Most smokers want to quit smoking, yet relapse rates are high. Understanding neural differences associated with tobacco use may help generate novel treatment options. Several animal studies have recently highlighted the central role of the thalamus in substance use disorders, but this research focus has been understudied in human smokers. Here, we investigated associations between structural and functional magnetic resonance imaging measures of the thalamus and its subnuclei to distinct smoking characteristics. We acquired anatomical scans of 32 smokers as well as functional resting-state scans before and after a cue-reactivity task. Thalamic functional connectivity was associated with craving and dependence severity, whereas the volume of the thalamus was associated with dependence severity only. Craving, which fluctuates rapidly, was best characterized by differences in brain function, whereas the rather persistent syndrome of dependence severity was associated with both brain structural differences and function. Our study supports the notion that functional versus structural measures tend to be associated with behavioural measures that evolve at faster versus slower temporal scales, respectively. It confirms the importance of the thalamus to understand mechanisms of addiction and highlights it as a potential target for brain-based interventions to support smoking cessation, such as brain stimulation and neurofeedback.

Thalamocortical functional connectivity and cannabis use in men with childhood attention-deficit/hyperactivity disorder.

Disruptions of the cortico-striato-thalamo-cortical circuit has been implicated in both attention-deficit/hyperactivity disorder and substance use disorder. Given the high prevalence of cannabis use among patients with attention-deficit/hyperactivity disorder, we set out to investigate the relationship between the two in the thalamus. We analyzed resting-state functional magnetic resonance imaging data obtained from the Addiction Connectome Preprocessed Initiative Multimodal Treatment Study of Attention-Deficit/Hyperactivity Disorder database. Functional connectivity maps were extracted to compare thalamic connectivity among adults who had been diagnosed with attention-deficit/hyperactivity disorder during childhood according to whether or not they used cannabis. The study participants included 18 cannabis users and 15 cannabis non-users with childhood attention-deficit/hyperactivity disorder. Our results revealed that adults with attention-deficit/hyperactivity disorder who used cannabis (n = 18) had significantly decreased functional connectivity between the thalamus and parietal regions, which was particularly prominent in the inferior parietal areas, in comparison with those who did not use cannabis (n = 15). Left thalamic functional connectivity with the inferior parietal and middle frontal areas and right thalamic functional connectivity with the inferior parietal and superior frontal areas were increased in non-users of cannabis with attention-deficit/hyperactivity disorder compared with a local normative comparison group (n = 7). In conclusion, adults with a childhood history of attention-deficit/hyperactivity disorder who do not use cannabis often have relatively stronger thalamoparietal and thalamofrontal connectivity, which may help reduce the risk of cannabis use.

Changes of insular function in lifelong premature ejaculation patients before and after SSRI administration.

Lifelong premature ejaculation (PE) is regarded as one of the most common male sexual dysfunction. We aimed to detect whether insula-related brain functional networks are altered in lifelong PE patients and whether such alterations are "normalised" after selective serotonin reuptake inhibitors (SSRI) administration. Twenty-three drug-naive lifelong PE patients and 30 healthy controls (HC) were recruited in current study. All subjects underwent resting-state functional magnetic resonance imaging (fMRI) scan at first. One hour after dapoxetine administration, all patients underwent fMRI scanning again. The degree centrality (DC), amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) analysis, and ROI-based functional connectivity (FC) analysis were applied to calculate the abnormalities in insula-related functions among three groups. Compared to HC group, PE patients at baseline showed significantly altered DC, ALFF, and ReHo value of the bilateral insula, which subsequently showed a "normalised" trend after dapoxetine administration. Additionally, compared to HC group, PE patients at baseline showed significantly decreased FC between insula and precentral gyrus, inferior frontal gyrus, middle/inferior temporal gyrus, and caudate, while patients after dapoxetine administration showed increased insula-related FC in anterior cingulate cortex and decreased FC in thalamus and middle/inferior temporal gyrus. The main effects of dapoxetine were located in precentral gyrus, inferior frontal gyrus, caudate, and limbic system. Our findings report altered brain mechanism of insula in lifelong PE patients and also indicate that dapoxetine can "normalise" the abnormal function of the insula to certain extent in lifelong PE patients.

Altered functional connectivity of the thalamus in primary angle-closure glaucoma patients: A resting-state fMRI study.

Background and objectivesGlaucoma is one of the leading irreversible causes of blindness worldwide, and previous studies have shown that there is abnormal functional connectivity (FC) in the visual cortex of glaucoma patients. The thalamus is a relay nucleus for visual signals; however, it is not yet clear how the FC of the thalamus is altered in glaucoma. This study investigated the alterations in thalamic FC in patients with primary angle-closure glaucoma (PACG) by using resting-state functional MRI (rs-fMRI). We hypothesized that PACG patients have abnormal FC between the thalamus and visual as well as extravisual brain regions.MethodsClinically confirmed PACG patients and age- and gender-matched healthy controls (HCs) were evaluated by T1 anatomical and functional MRI on a 3 T scanner. Thirty-four PACG patients and 33 HCs were included in the rs-fMRI analysis. All PACG patients underwent complete ophthalmological examinations; included retinal nerve fiber layer thickness (RNFLT), intraocular pressure (IOP), average cup-to-disc ratio (A-C/D), and vertical cup-to-disc ratio (V-C/D). After the MRI data were preprocessed, the bilateral thalamus was chosen as the seed point; and the differences in resting-state FC between groups were evaluated. The brain regions that significantly differed between PACG patients and HCs were identified, and the correlations were then evaluated between the FC coefficients of these regions and clinical variables.ResultsCompared with the HCs, the PACG patients showed decreased FC between the bilateral thalamus and right transverse temporal gyrus, between the bilateral thalamus and left anterior cingulate cortex, and between the left thalamus and left insula. Concurrently, increased FC was found between the bilateral thalamus and left superior frontal gyrus in PACG patients. The FC between the bilateral thalamus and left superior frontal gyrus was positively correlated with RNFLT and negatively correlated with the A-C/D and V-C/D. The FC between the left thalamus and left insula was negatively correlated with IOP.ConclusionExtensive abnormal resting-state functional connections between the thalamus and visual and extravisual brain areas were found in PACG patients, and there were certain correlations with clinical variables, suggesting that abnormal thalamic FC plays an important role in the progression of PACG.

Modulation of thalamic network connectivity using transcranial direct current stimulation based on resting-state functional magnetic resonance imaging to improve hypoxia-induced cognitive impairments.

Hypoxic conditions at high altitudes severely affect cognitive functions such as vigilance, attention, and memory and reduce cognitive ability. Hence, there is a critical need to investigate methods and associated mechanisms for improving the cognitive ability of workers at high altitudes. This study aimed to use transcranial direct current stimulation (tDCS) to modulate thalamic network functional connectivity to enhance cognitive ability. We recruited 20 healthy participants that underwent hypoxia exposure in a hypoxic chamber at atmospheric pressure to simulate a hypoxic environment at 4,000 m. Participants received both sham and real stimulation. tDCS significantly improved the participants’ emotional status, including depression, fatigue, and energy level. These effects were sustained for more than 6 h (P < 0.05 at the second to fifth measurements). In addition, tDCS enhanced vigilance, but this was only effective within 2 h (P < 0.05 at the second and third measurements). Central fatigue was significantly ameliorated, and cerebral blood oxygen saturation was increased within 4 h (P < 0.05 at the second, third, and fourth measurements). Furthermore, functional connectivity results using the thalamus as a seed revealed enhanced connectivity between the thalamus and hippocampus, cingulate gyrus, and amygdala after tDCS. These results indicated that tDCS increased local cerebral blood oxygen saturation and enhanced thalamic network connectivity in a hypoxic environment, thereby improving vigilance, depression, fatigue, and energy levels. These findings suggest that tDCS may partially rescue the cognitive decline caused by hypoxia within a short period. This approach affords a safe and effective cognitive enhancement method for all types of high-altitude workers with a large mental load.