This study explored how the human cortical folding pattern composed of convex gyri and concave sulci affected single-subject morphological brain networks, which are becoming an important method for studying the human brain connectome. We found that gyri-gyri networks exhibited higher morphological similarity, lower small-world parameters, and lower long-term test-retest reliability than sulci-sulci networks for cortical thickness- and gyrification index-based networks, while opposite patterns were observed for fractal dimension-based networks. Further behavioral association analysis revealed that gyri-gyri networks and connections between gyral and sulcal regions significantly explained inter-individual variance in Cognition and Motor domains for fractal dimension- and sulcal depth-based networks. Finally, the clinical application showed that only sulci-sulci networks exhibited morphological similarity reductions in major depressive disorder for cortical thickness-, fractal dimension-, and gyrification index-based networks. Taken together, these findings provide novel insights into the constraint of the cortical folding pattern to the network organization of the human brain.
Humans ; Cerebral Cortex/anatomy & histology* ; Male ; Female ; Magnetic Resonance Imaging ; Adult ; Connectome/methods* ; Young Adult ; Nerve Net/anatomy & histology* ; Neural Pathways ; Depressive Disorder, Major/diagnostic imaging*

Optical imaging of intrinsic signals is a secondary image of the cerebral cortex. The weak optical signal is decided by anatomical structure of brain. The spatial filter is a powerful technology for de-noising and image enhancement. We used different linear and nonlinear filters to deal with optical imaging. Furthermore, we compared the degree of noise suppression and discussed the image details. Our result showed that nonlinear median filter can keep more image details with effective noise reduction. It is useful for image enhancement of optical imaging.
Animals ; Artifacts ; Blood Vessels ; anatomy & histology ; Cats ; Cerebral Cortex ; anatomy & histology ; physiology ; Cerebrovascular Circulation ; physiology ; Female ; Image Enhancement ; methods ; Image Processing, Computer-Assisted ; instrumentation ; methods ; Male ; Optical Imaging ; methods ; Photic Stimulation

The finite element method (FEM) plays an important role in solving the brain deformation problem in the image guided neurosurgery system. The position of the brain cortex during the surgery provides the boundary condition for the FEM model. In this paper, the information of brain cortex is represented by the unstructured points and the boundary condition is achieved by the processing of unstructured points. The processing includes the mapping of texture, segmentation, simplification and denoising. The method of k-nearest clustering based on local surface properties is used to simplify and denoise the unstructured point clouds. The results of experiment prove the efficiency of point clouds processing.
Brain ; anatomy & histology ; surgery ; Cerebral Cortex ; anatomy & histology ; Finite Element Analysis ; Humans ; Imaging, Three-Dimensional ; methods ; Models, Anatomic ; Neuronavigation ; methods ; Neurosurgery ; instrumentation ; methods ; Surgery, Computer-Assisted ; methods ; User-Computer Interface

OBJECTIVETo study human vestibular cerebral representations by combining right-sided ice-water stimulation at 0 degree C with blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI) and to evaluate the value of this method in the functional localization of human vestibular cortex.

METHODSTwenty right-handed volunteers (12 men and 8 women) received unilateral irrigation of the right external auditory meatu for 15 s with 15 ml of water at 0 degrees C during fMRI in complete darkness. The functional imaging of brain cortex was acquired with a 1.5-T MRI scanner (Signa Infinity Twin + Excite; General Electric Co., USA). The successive functional images from each subject were analyzed as a group with statistical parametric mapping software (SPM 99).

RESULTSUltimately, data obtained from 17 subjects were analyzed (3 subjects were eliminated from data because of head movement exceeding 2 mm). The group analysis showed bilateral (particularly left-sided) cortical activation, associated with caloric stimulus involving in temporoparietal junction extending into the posterior insula, supramarginal gyrus in the inferior parietal lobe, precuneus, supplementary motor area (SMA), the ventrolateral portion of the occipital lobe, cuneus and lingual gyrus, superior temporal gyrus and cingular cortex.

CONCLUSIONSIce-water stimulation at 0 degree C in fMRI reveals a widespread cortical network involved in vestibular signal processing in human. As the functional localization of vestibular cortex could be determined precisely, ice-water stimulation at 0 degree C in fMRI would hold great promise as a sensitive and reproducible tool for the research in human vestibular cortex.

Adult ; Brain Mapping ; Cerebral Cortex ; anatomy & histology ; physiology ; Ear, Inner ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Vestibular Nuclei ; anatomy & histology ; physiology ; Young Adult

OBJECTIVETo investigate morphological changes of capillary in aging brain and explore the role of vascular factor in brain aging.

METHODSTwenty-eight brains of individuals (mean age 65 years) who died without clinical or pathological involvement of nervous system and 6 brains of Alzheimer's disease (AD) patients (mean age 83 years) were obtained at autopsy. Sections from frontal lobe, occipital lobe, striatum and hippocampus of normal subjects and sections from hippocampus of AD patients were used for hematoxylin eosin (HE), lox fast blue (LFB), toluidine blue stains and ulex europaeus agglutinin (UEA) immunostaining. After observations of morphological changes of neuron and capillary, computer-aid image analysis was performed to quantify numerical density and area density of neuron and capillary in frontal lobe, occipital lobe, putamen, CA3 sector of normal subjects and CA3 sector of AD patients. Numerical ratio and area ratio of neuron and capillary were then calculated. Correlations between neuron/capillary ratio and age were estimated using Pearson's correlation test. Difference of neuron/capillary ratio in CA3 sectors between AD patients and advanced aged normal subjects (> 75 years) was analyzed with Student's t-test.

RESULTSSeveral pathological microvascular changes, including increased tortuosity, looping, bundling, stringing, and effacement of endothelia were seen in aged subjects and more prevalent in AD patients. Numerical ratio and area ratio of neuron and capillary of frontal lobe, occipital lobe and putamen significantly increased with age in normal aging subjects.

CONCLUSIONSMorphological changes and relative decrease in number and capacity of capillary in aging brain may reduce cerebral blood flow and metabolism, and consequently result in functional impairment of aging brain. Vascular factors may play an important role in the development of brain aging.

Adult ; Aged ; Aged, 80 and over ; Aging ; Alzheimer Disease ; etiology ; pathology ; Capillaries ; anatomy & histology ; pathology ; Cell Count ; Cerebral Cortex ; blood supply ; pathology ; Female ; Frontal Lobe ; blood supply ; pathology ; Hippocampus ; blood supply ; pathology ; Humans ; Image Processing, Computer-Assisted ; Male ; Middle Aged ; Neurons ; pathology ; Occipital Lobe ; blood supply ; pathology

OBJECTIVETo localize the language cortex associated with Chinese word processing by magnetic source imaging (MSI).

METHODSEight right-handed and one left-handed healthy native Chinese subjects were examined by magnetoencephalography (MEG) and a 1.5T magnetic resonance imaging (MRI) unit. All subjects were given pure tone stimuli 50 times, 150 pairs of Chinese words (meaning related or unrelated) auditory stimuli, and pure tone stimuli subsequently 50 times. Evoked response fields time locked to the pure tone and Chinese words were recorded using a whole-head neuromagnetometer in real-time. The acquired data were averaged by the acquisition computer according to the response to the pure tone, related pairs of words and unrelated pairs of words. The data obtained by MEG were superimposed on MRI, using a GE Signa 1.5T system.

RESULTSMEG, showed there were two obviously higher magnetic waves named M50 and M100, which were localized in the bilateral transverse temporal gyri in all subjects. The responses to the pairs of Chinese words (meaning related or unrelated) were similar in the same hemisphere of the same subjects. There was a higher peak during 300 - 600 ms in the right hemisphere of one left handed subject, but no peak in the left hemisphere, indicating that the language dominant hemisphere was localized in the right hemisphere. Superimposing the MEG data on MRI, the language area was localized in the Wernicke's areas. A 300 - 600 ms response peak was obsarved in each hemisphere (the amplitude of the 300 - 600 ms response peak in each hemisphere was almost the same) in two right-handed subjects, showing that the language area was localized in the 2 hemispheres in the two subjects. There was one peak in each hemisphere (300 - 600 ms response) in 6 subjects, but the amplitude of the wave in the left hemisphere in the 6 subjects was much higher than that in the right hemisphere. By choosing randomly from the later component (300 - 600 ms response) several time points and superimposing them on MRI, all time points were localized in the posterior part of the superior temporal gyri, which is the Wernicke's areas.

CONCLUSIONSComparing with the later component of the bilateral hemispheres, the wave amplitude in the language dominant hemisphere was much higher than that in the non-language dominant hemisphere. The language areas could be identified by judging whether meanings of pairs of Chinese words were related or not.

Adolescent ; Adult ; Cerebral Cortex ; anatomy & histology ; Female ; Humans ; Language ; Magnetic Resonance Imaging ; Magnetoencephalography ; Male