scholarly journals Atypical Antipsychotics Mediate Dynamics of Intrinsic Brain Activity in Early-Stage Schizophrenia? A Preliminary Study

2021 ◽  
Vol 18 (12) ◽  
pp. 1205-1212
Author(s):  
Yingchan Wang ◽  
Yuchao Jiang ◽  
Dengtang Liu ◽  
Jianye Zhang ◽  
Dezhong Yao ◽  
...  
Keyword(s):  
Negative Symptoms ◽  
Atypical Antipsychotics ◽  
Early Stage ◽  
Brain Activity ◽  
Low Frequency ◽  
Antipsychotic Treatment ◽  
Before And After ◽  
Middle Occipital Gyrus ◽  
The Right ◽  
Intrinsic Brain Activity

Objective Abnormalities of static brain activity have been reported in schizophrenia, but it remains to be clarified the temporal variability of intrinsic brain activities in schizophrenia and how atypical antipsychotics affect it.Methods We employed a resting-state functional magnetic resonance imaging (rs-fMRI) and a sliding-window analysis of dynamic amplitude of low-frequency fluctuation (dALFF) to evaluate the dynamic brain activities in schizophrenia (SZ) patients before and after 8-week antipsychotic treatment. Twenty-six schizophrenia individuals and 26 matched healthy controls (HC) were included in this study.Results Compared with HC, SZ showed stronger dALFF in the right inferior temporal gyrus (ITG.R) at baseline. After medication, the SZ group exhibited reduced dALFF in the right middle occipital gyrus (MOG.R) and increased dALFF in the left superior frontal gyrus (SFG.L), right middle frontal gyrus (MFG.R), and right inferior parietal lobule (IPL.R). Dynamic ALFF in IPL.R was found to significant negative correlate with the Scale for the Assessment of Negative Symptoms (SANS) scores at baseline.Conclusion Our results showed dynamic intrinsic brain activities altered in schizophrenia after short term antipsychotic treatment. The findings of this study support and expand the application of dALFF method in the study of the pathological mechanism in psychosis in the future.

scholarly journals Dynamic Changes of Amplitude of Low-Frequency Fluctuations in Patients With Diabetic Retinopathy

2021 ◽  
Vol 12 ◽  
Author(s):  
Xin Huang ◽  
Zhi Wen ◽  
Chen-Xing Qi ◽  
Yan Tong ◽  
Yin Shen
Keyword(s):  
Diabetic Retinopathy ◽  
Brain Activity ◽  
Memory Function ◽  
Low Frequency ◽  
Parahippocampal Gyrus ◽  
Cerebral Activity ◽  
Visual Cortices ◽  
Middle Occipital Gyrus ◽  
The Right ◽  
Intrinsic Brain Activity

Background: Growing evidence demonstrate that diabetic retinopathy (DR) patients have a high risk of cognitive decline and exhibit abnormal brain activity. However, neuroimaging studies thus far have focused on static cerebral activity changes in DR patients. The characteristics of dynamic cerebral activity in patients with DR are poorly understood.Purpose: The purpose of the study was to investigate the dynamic cerebral activity changes in patients with DR using the dynamic amplitude of low-frequency fluctuation (dALFF) method.Materials and methods: Thirty-four DR patients (18 men and 16 women) and 38 healthy controls (HCs) (18 males and 20 females) closely matched in age, sex, and education were enrolled in this study. The dALFF method was used to investigate dynamic intrinsic brain activity differences between the DR and HC groups.Results: Compared with HCs, DR patients exhibited increased dALFF variability in the right brainstem, left cerebellum_8, left cerebellum_9, and left parahippocampal gyrus. In contrast, DR patients exhibited decreased dALFF variability in the left middle occipital gyrus and right middle occipital gyrus.Conclusion: Our study highlighted that DR patients showed abnormal variability of dALFF in the visual cortices, cerebellum, and parahippocampal gyrus. These findings suggest impaired visual and motor and memory function in DR individuals. Thus, abnormal dynamic spontaneous brain activity might be involved in the pathophysiology of DR.

scholarly journals Altered Temporal Dynamic Intrinsic Brain Activity in Late Blindness

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Xin Huang ◽  
Zhi Wen ◽  
Chen-Xing Qi ◽  
Yan Tong ◽  
Han-Dong Dan ◽  
...  
Keyword(s):  
Visual Processing ◽  
Brain Activity ◽  
Gaussian Random Field ◽  
Low Frequency ◽  
Sliding Window ◽  
Crossmodal Plasticity ◽  
The Difference ◽  
Structural Architecture ◽  
The Right ◽  
Intrinsic Brain Activity

Previous neuroimaging studies demonstrated that visual deprivation triggers significant crossmodal plasticity in the functional and structural architecture of the brain. However, prior neuroimaging studies focused on the static brain activity in blindness. It remains unknown whether alterations of dynamic intrinsic brain activity occur in late blindness (LB). This study investigated dynamic intrinsic brain activity changes in individuals with late blindness by assessing the dynamic amplitude of low-frequency fluctuations (dALFFs) using sliding-window analyses. Forty-one cases of late blindness (LB) (29 males and 12 females, mean age: 39.70±12.66 years) and 48 sighted controls (SCs) (17 males and 31 females, mean age: 43.23±13.40 years) closely matched in age, sex, and education level were enrolled in this study. The dALFF with sliding-window analyses was used to compare the difference in dynamic intrinsic brain activity between the two groups. Compared with SCs, individuals with LB exhibited significantly lower dALFF values in the bilateral lingual gyrus (LING)/calcarine (CAL) and left thalamus (THA). LB cases also showed considerably decreased dFC values between the bilateral LING/CAL and the left middle frontal gyrus (MFG) and between the left THA and the right LING/cerebelum_6 (CER) (two-tailed, voxel-level P<0.01, Gaussian random field (GRF) correction, cluster-level P<0.05). Our study demonstrated that LB individuals showed lower-temporal variability of dALFF in the visual cortices and thalamus, suggesting lower flexibility of visual thalamocortical activity, which might reflect impaired visual processing in LB individuals. These findings indicate that abnormal dynamic intrinsic brain activity might be involved in the neurophysiological mechanisms of LB.

Assessment of cerebral low-frequency oscillations in patients with retinal vein occlusion: a preliminary functional MRI study

2019 ◽  
Vol 61 (6) ◽  
pp. 813-820 ◽  
Author(s):  
Qing Gao ◽  
Bin Peng ◽  
Xin Huang ◽  
Chen-Xing Qi ◽  
Yan Tong ◽  
...  
Keyword(s):  
Retinal Vein Occlusion ◽  
Brain Activity ◽  
Low Frequency ◽  
Frequency Fluctuation ◽  
Healthy Controls ◽  
Vein Occlusion ◽  
Lower Amplitude ◽  
Frequency Fluctuations ◽  
Middle Occipital Gyrus ◽  
Intrinsic Brain Activity

Background There is increasing evidence that patients with retinal vein occlusion exhibit cerebral vascular changes and are at an increased risk of stroke. However, it remains unknown whether patients with retinal vein occlusion exhibit changes in intrinsic brain activity. Purpose This study investigated intrinsic brain activity changes in patients with retinal vein occlusion by assessing the amplitude of low-frequency fluctuations. Material and Methods Forty-five patients with retinal vein occlusion (22 men, 23 women, mean age 56.55 ± 6.97 years) and 43 healthy controls (13 men, 30 women; mean age 53.53 ± 8.19 years) closely matched in age, sex, and education level underwent resting-state MRI scans. The amplitude of low-frequency fluctuation method was used to compare intrinsic brain activity between the two groups. Results Compared with healthy controls, patients with retinal vein occlusion exhibited significantly lower amplitude of low-frequency fluctuation values in the left middle occipital gyrus, right middle occipital gyrus, and right calcarine. However, patients with retinal vein occlusion showed significantly higher amplitude of low-frequency fluctuations in the bilateral cerebellum 6, right hippocampus, left insula, and left fusiform (voxel-level P < 0.01, Gaussian random field correction, cluster-level P < 0.05). Conclusion Our results demonstrated that patients with retinal vein occlusion showed abnormal spontaneous neural activities in the visual cortices, cerebellum, and Papez circuit, which might indicate impaired vision, cognition, and emotional function in patients with retinal vein occlusion. These findings offer important insights into the neural mechanism of retinal vein occlusion.

scholarly journals Abnormal Regional Spontaneous Brain Activity and Its Indirect Effect on Spasm Ratings in Patients With Hemifacial Spasm

2020 ◽  
Vol 14 ◽  
Author(s):  
Fei-Fei Luo ◽  
Hui Xu ◽  
Ming Zhang ◽  
Yuan Wang
Keyword(s):  
Hemifacial Spasm ◽  
Indirect Effect ◽  
Brain Activity ◽  
Low Frequency ◽  
Posterior Cingulate Cortex ◽  
Angular Gyrus ◽  
Neurovascular Compression ◽  
Regional Brain ◽  
Middle Occipital Gyrus ◽  
The Right

PurposeThree classical methods of resting-state functional magnetic resonance imaging (rs-fMRI) were employed to explore the local functional abnormalities and their effect on spasm ratings in hemifacial spasm (HFS) patients.MethodsThirty HFS patients and 30 matched healthy controls (HCs) were recruited. Rs-fMRI data, neurovascular compression (NVC) degree and spasm severity were collected in each subject. Fractional amplitude of low-frequency fluctuation (fALFF), regional homogeneity (ReHo), and degree centrality (DC) were calculated in the whole brain voxels. Two sample t-tests were performed to investigate group differences of fALFF, ReHo, and DC. Correlation analysis was performed to assess the relationships between the regional brain abnormalities and clinical variables in HFS.ResultsCompared with HCs, HFS patients exhibited increased fALFF in the left precuneus and right posterior cingulate cortex (PCC), together with increased ReHo in the bilateral PCC and bilateral precuneus. Decreased ReHo was observed in the right middle occipital gyrus (MOG), right superior occipital gyrus (SOG), right cuneus, and right angular gyrus (AG) in HFS patients. Moreover, ReHo in the right PCC were positively correlated with NVC degree and spasm severity in HFS patients, respectively. Mediation analysis revealed that increased ReHo in the right PCC regulated the neurovascular compression degree, and further resulted in increased spasm ratings.ConclusionOur study revealed regional brain dysfunctions from different perspectives and an indirect effect of ReHo in right PCC on spasm ratings predominantly through the alteration of NVC.

scholarly journals Dynamic Altered Amplitude of Low-Frequency Fluctuations in Patients With Major Depressive Disorder

2021 ◽  
Vol 12 ◽  
Author(s):  
Ruiping Zheng ◽  
Yuan Chen ◽  
Yu Jiang ◽  
Mengmeng Wen ◽  
Bingqian Zhou ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
Neural Activity ◽  
Temporal Variability ◽  
Brain Activity ◽  
Low Frequency ◽  
First Episode ◽  
Posterior Lobe ◽  
Major Depressive ◽  
Drug Naïve ◽  
The Right

Background: Major depressive disorder (MDD) has demonstrated abnormalities of static intrinsic brain activity measured by amplitude of low-frequency fluctuation (ALFF). Recent studies regarding the resting-state functional magnetic resonance imaging (rs-fMRI) have found the brain activity is inherently dynamic over time. Little is known, however, regarding the temporal dynamics of local neural activity in MDD. Here, we investigated whether temporal dynamic changes in spontaneous neural activity are influenced by MDD.Methods: We recruited 81 first-episode, drug-naive MDD patients and 64 age-, gender-, and education-matched healthy controls who underwent rs-fMRI. A sliding-window approach was then adopted for the estimation of dynamic ALFF (dALFF), which was used to measure time-varying brain activity and then compared between the two groups. The relationship between altered dALFF variability and clinical variables in MDD patients was also analyzed.Results: MDD patients showed increased temporal variability (dALFF) mainly focused on the bilateral thalamus, the bilateral superior frontal gyrus, the right middle frontal gyrus, the bilateral cerebellum posterior lobe, and the vermis. Furthermore, increased dALFF variability values in the right thalamus and right cerebellum posterior lobe were positively correlated with MDD symptom severity.Conclusions: The overall results suggest that altered temporal variability in corticocerebellar–thalamic–cortical circuit (CCTCC), involved in emotional, executive, and cognitive, is associated with drug-naive, first-episode MDD patients. Moreover, our study highlights the vital role of abnormal dynamic brain activity in the cerebellar hemisphere associated with CCTCC in MDD patients. These findings may provide novel insights into the pathophysiological mechanisms of MDD.

scholarly journals The Cumulative Therapeutic Effect of Acupuncture Treatment in Patients With Migraine Without Aura: Evidence From Dynamic Alterations of Intrinsic Brain Activity and Effective Connectivity Analysis

2021 ◽  
Author(s):  
Yilei Chen ◽  
Yingjie Kang ◽  
Shilei Luo ◽  
Shanshan Liu ◽  
Bo Wang ◽  
...  
Keyword(s):  
Migraine Attack ◽  
Therapeutic Effect ◽  
Migraine Without Aura ◽  
Acupuncture Treatment ◽  
Brain Activity ◽  
Effective Connectivity ◽  
Life Questionnaire ◽  
Precentral Gyrus ◽  
The Right ◽  
Intrinsic Brain Activity

Abstract Background: The underlying neurological mechanism of acupuncture treatment in migraine without aura (MwoA) remains unclear. Therefore, we explored the dynamic alterations of intrinsic brain activity and effective connectivity in patients with MwoA after acupuncture treatment.Methods:The fMRI scans were separately obtained at baseline, after the first and after the 12th acupuncture sessions in 40 patients with MwoA. The acupuncture treatments were finished within 6 weeks as twice a week. 36 matched healthy controls (HCs) were recruited and performed once fMRI scan. The dynamic amplitude of low-frequency fluctuation (dALFF) and dynamic granger causality analysis(GCA) were used to analyze the difference of different time points in patients with MwoA. The correlation analyses were performed in dALFF variability, dynamic effective connectivity (DEC) variability with clinical variables in patients with MwoA.Results:Compared with HCs, Patients with MwoA at baseline showed decreased dALFF variability in regions within rostral ventromedial medulla (RVM), the superior lobe of left cerebellum (Cerebelum_Crus1_L), the right inferior frontal gyrus, triangular part (IFGtriang.R), the right median cingulate and paracingulate gyri (DCG.R), the right precuneus (PCUN.R), and the left inferior parietal, supramarginal and angular gyri (IPL.L), increased dALFF variability only in the left inferior occipital gyrus (IOG.L). After acupuncture treatment, the decreased dALFF variability of the RVM, Cerebelum_Crus1_L , and PCUN.R progressively recovered, the RVM revealed gradually increased DEC variability to the right middle frontal gyrus (MFG.R), the left insula (INS.L), the right precentral gyrus (PreCG.R), and the right supramarginal gyrus (SMG.R). And enhanced DEC variability from the right fusiform gyrus (FFG.R) to RVM. Furthermore, the increased DEC variability were found from Cerebelum_Crus1_L to the left middle occipital gyrus (MOG.L) and the left precentral gyrus (PreCG.L), from PCUN.R to the right thalamus (THA.R). These dALFF variabilities were significantly positive correlated with frequency of migraine attack and negative correlated with disease duration at baseline, dynamic GCA coefficients were significantly positive correlated with Migraine-Specific Quality of Life Questionnaire (MSQ) score, negative correlated with frequency of migraine attack and visual analog scale (VAS) score postacupuncture treatment.Conclusions:Our results provide insight into dynamic alterations from the perspective of dynamic local brain activity and effective connectivity for the understanding mechanisms of cumulative therapeutic effect of acupuncture in patients with MwoA.Trial registration: ChiCTR, ChiCTR1900023105. Registered 11 May 2019, http://www.chictr.org.cn/showproj.aspx?proj=36959.

Receptor mechanisms of antipsychotic drug atypicality

1998 ◽  
Vol 13 (S1) ◽  
pp. 5s-8s
Author(s):  
GP Reynolds
Keyword(s):  
Side Effects ◽  
Animal Models ◽  
Negative Symptoms ◽  
Atypical Antipsychotics ◽  
Mechanisms Of Action ◽  
Antipsychotic Treatment ◽  
Extrapyramidal Side Effects ◽  
Treatment Resistant ◽  
Pharmacological Profile ◽  
New Compounds

SummaryRecent advances in antipsychotic treatment of schizophrenia have offered several new compounds which avoid many of the limitations of the classical antipsychotics. These so-called ‘atypical’ antipsychotics have fewer extrapyramidal side effects, greater efficacy against negative symptoms and greater efficacy in otherwise treatment-resistant patients. However, the mechanism of action of these atypical antipsychotics is still unclear. The several receptors currently implicated in the pharmacological profile of these atypical antipsychotics include subtypes of those for dopamine, serotonin, noradrenaline, and acetylcholine among others. The current hypotheses for possible mechanisms of action of atypical antipsychotics are discussed along with the experimental correlates of antipsychotic efficacy in animal models.

scholarly journals Longitudinal Spatial Patterns of Intrinsic Brain Activity and Functional Connectivity in Upper Limb Amputees Patients

2020 ◽  
Author(s):  
bingbo bao ◽  
xuyun hua ◽  
haifeng wei ◽  
pengbo luo ◽  
hongyi zhu ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Spatial Patterns ◽  
Brain Plasticity ◽  
Brain Activity ◽  
Low Frequency ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Brain Network ◽  
Intrinsic Connectivity ◽  
Intrinsic Brain Activity

Abstract Background: Amputation in adults is a serious condition and most patients were associated with the remapping of representations in motor and sensory brain network. Methods: The present study includes 8 healthy volunteers and 16 patients with amputation. We use resting-state fMRI to investigate the local and extent brain plasticity in patients suffering from amputation simultaneously. Both the amplitude of low-frequency fluctuations (ALFF) and degree centrality (DC) were used for the assessment of neuroplasticity in central level. Results: We described changes in spatial patterns of intrinsic brain activity and functional connectivity in amputees in the present study and we found that not only the sensory and motor cortex, but also the related brain regions involved in the functional plasticity after upper extremity deafferentation. Conclusion: Our findings showed local and extensive cortical changes in the sensorimotor and cognitive-related brain regions, which may imply the dysfunction in not only sensory and motor function, but also sensorimotor integration and motor plan. The activation and intrinsic connectivity in the brain changed a lot showed correlation with the deafferentation status.

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