Small-world Network Features of Brain Functional Network as Strong Void Perception for Healthy Female / 中国康复理论与实践

Objective:To identify the small-world network property of brain functional network provoked by a strong desire to void in healthy women. Methods:From 2017 to 2018, 21 healthy women were enrolled, and scanned with resting-state functional magnetic resonance imaging under the empty bladder and strong desire to void, respectively. Brain connection matrix was established with Pearson's correlation analysis, and the differences in topologic properties between the two conditions were identified with paired t-test and Bonferroni correction. The small-world parameters, named clustering coefficient (Cp), characteristic path length (Lp), global efficiency (Eglob), local efficiency (Eloc) and nodal efficiency (Enodal) were calculated. Results:There were two women dropped down because of head moving. For the other 19 women, the brain connection presented a small-world network property under the both conditions. Compared with the empty bladder, Cp, Lp, and Eloc decreased, and Eglob increased under the strong desire to void (P < 0.05); while Enodal increased in left inferior frontal gyrus and superior frontal gyrus; right cingulate gyrus, middle occipital gyrus and middle temporal gyrus; and bilateral gyrus rectus and inferior parietal lobes; and decreased in bilateral fusiform gyrus, calcarine fissure and surrounding, and lingual gyrus (P < 0.05). Conclusion:Brain functional network presents a small-world network property under both empty bladder and a strong desire to void. The regulation of lower urinary tract function involves the coordination of multiple brain regions.

Relationship between Small-world Network and Cognitive Impairment for Patients with White Matter Lesions Based On Diffusion Tensor Imaging / 中国康复理论与实践

Objective:To explore the relationship between small-worldness of brain network and cognitive impairment in patients with white matter lesions (WMLs) based on diffusion tensor imaging (DTI). Methods:From January, 2016 to December, 2017, 46 WMLs patients and 36 controls matched genders, ages and education levels from Beijing Tiantan Hospital were screened with DTI. The patients were divided into vascular cognitive impairment non-dementia (VCIND) and vascular dementia (VaD) groups according to the results of cognitive assessments. The brain structure network was created based on DTI data, and the topological properties of the whole-brain small-world network were calculated, and the correlation between the small-worldness and the severity of cognitive impairment was analyzed. Results:The global efficiency, local efficiency, shortest path length and clustering coefficient were different between the patients and the controls (F > 3.252, P < 0.05), as well as the properties of the small-world network, λ, γ and σ (F > 7.378, P < 0.01). The λ, γ and σ were correlated with the total score of Montreal Cognitive Assessment (|r| > 0.402, P < 0.05). Conclusion:The brain structure network is small-world network for patients with WMLs, and the decrease of small-world properties may relate to the cognitive impairment.

The research on dynamic properties of the small world neural network based on the synaptic plasticity / 生物医学工程学杂志

The artificial neural network has the ability of the information processing and storage, good adaptability, strong learning function, association function and fault tolerance function. The research on the artificial neural network is mostly focused on the dynamic properties due to fact that the applications of artificial neural networks are related to its dynamic properties. At present, the researches on the neural network are based on the hierarchical network which can not simulate the real neural network. As a high level of abstraction of real complex systems, the small world network has the properties of biological neural networks. In the study, the small world network was constructed and the optimal parameter of the small word network was chosen based on the complex network theory firstly. And then based on the regulation mechanism of the synaptic plasticity and the topology of the small world network, the small world neural network was constructed and dynamic properties of the neural network were analyzed from the three aspects of the firing properties, dynamic properties of synaptic weights and complex network properties. The experimental results showed that with the increase of the time, the firing patterns of excitatory and inhibitory neurons in the small world neural network didn't change and the firing time of the neurons tended to synchronize; the synaptic weights between the neurons decreased sharply and eventually tended to be steady; the connections in the neural network were weakened and the efficiency of the information transmission was reduced, but the small world attribute was stable. The dynamic properties of the small world neural network vary with time, and the dynamic properties can also interact with each other: the firing synchronization of the neural network can affect the distribution of synaptic weights to the minimum, and then the dynamic changes of the synaptic weights can affect the complex network properties of the small world neural network.

Small-world networks analysis of leukoaraiosis: a rest-state functional MRI study / 中华行为医学与脑科学杂志

Objective To explore the effect of leukoaraiosis (LA) on the efficiency of the brain function network and to analyze the features of the "small world" network with graph theory method.Methods This study involved 34 LA patients from the Department of Neurology,Beijing Tiantan hospital,Capital Medical University from January 2014 to September 2015 and 23 age-and sex-matched healthy controls(NC group).All participants underwent the neurocognitive tests including M MSE,MoCA and clinical dementia rating(CDR).The subjects were divided into LA with cognitive normal group (CN) (n=11) and LA patients with vascular cognitive impairment-non dementia group(VCIND) (n=23).Functional MRI (fMRI) was employed at resting state.And then,the functional network establishment and small-world network metrics (characteristic clustering coefficient and path length) were computed using graph analytical methods.Results In the range of 0.05 ≤ Kcost ≤ 0.5,the functional networks fitted the definition of small-worldness in LA (CN),LA(VCIND) and NC groups(δ＞1).The Lambda of group LA(CN) and LA (VCIND) were smaller than that of NC group at each threshold,and more closing to 1.The gamma of group LA(CN) were higher than that of NC group at each threshold.While the gamma of group LA(VCIND)were lower than that of NC group at each threshold.The sigma of group LA(CN) were higher than that of NC group at each threshold.Conclusion The LA patients exhibit abnormal small-world network properties.And compared with HCs,small world properties in LA (CN) patients have been increased,while that in LA (VCIND) patients have been reduced,which manifested that the altered topological properties may be responsible for cognitive dysfunction in LA patients.

Anatomical Brain Connectivity Map of Korean Children

PURPOSE: The purpose of this study is to establish the method generating human brain anatomical connectivity from Korean children and evaluating the network topological properties using small-world network analysis. MATERIALS AND METHODS: Using diffusion tensor images (DTI) and parcellation maps of structural MRIs acquired from twelve healthy Korean children, we generated a brain structural connectivity matrix for individual. We applied one sample t-test to the connectivity maps to derive a representative anatomical connectivity for the group. By spatially normalizing the white matter bundles of participants into a template standard space, we obtained the anatomical brain network model. Network properties including clustering coefficient, characteristic path length, and global/local efficiency were also calculated. RESULTS: We found that the structural connectivity of Korean children group preserves the small-world properties. The anatomical connectivity map obtained in this study showed that children group had higher intra-hemispheric connectivity than inter-hemispheric connectivity. We also observed that the neural connectivity of the group is high between brain stem and motorsensory areas. CONCLUSION: We suggested a method to examine the anatomical brain network of Korean children group. The proposed method can be used to evaluate the efficiency of anatomical brain networks in people with disease.