SEARCH · PubMed Health
Results for “Brain Mapping”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
[Relationship between intraoperative brain mapping and pre- or post-operative functional MRI in patients with glioma].
Explore the source record for details and available documents.
Drug profiling by computed electroencephalography and brain maps, with special consideration of sertraline and its psychometric effects.
The five main psychopharmacological drug groups are reviewed in respect of their effects on the pharmaco-electroencephalogram (pharmaco-EEG), with special consideration given to drug profiling by topographic brain mapping. In addition, the CNS effects of sertraline (100, 200, and 400 mg), zimelidine (100 mg), and placebo were studied. The pharmaco-EEG profiles of both sertraline (100 mg) and zimelidine were indicative of vigilance-enhancement seen after desipramine-type antidepressants; with higher sertraline dosages there was a change toward the sedation associated with imipramine-type antidepressants. Both sertraline (100 mg) and zimelidine improved psychometric performance, although some deterioration occurred with higher sertraline (200 and 400 mg) doses. Psychophysiological variables showed dose-dependent changes in CNS activation and pupillary dilatation. Adverse effects were minimal with both sertraline (100 mg) and zimelidine, while nausea and vomiting increased with sertraline 200 and 400 mg.
Brain-mapping abnormalities in a family with three obsessive compulsive children.
Brain electrical activity mapping (BEAM) and personality disorder assessment (Millon Clinical Multiaxial Inventory-II) were performed on a married couple and their four children. Three of the children had previously been identified as having obsessive compulsive disorder (OCD). Temporal lobe abnormalities were found in all four children but in neither parent. If there is a neurophysiologic basis for this subtype of OCD, brain electrical abnormalities may be necessary, but not sufficient, to produce the clinical syndrome. Delineation of specific electrophysiological and personality characteristics may help define subtypes of obsessive compulsive disorder.
[Surgery of the central nervous system: value of preoperative functional brain mapping by direct electric stimulation].
Explore the source record for details and available documents.
Tridimensional animated brain mapping from conventional paper-ink EEG recordings.
One of the most powerful functional evaluations of the electrical activity of the brain is the EEG imaging, but wide clinical use is limited by its costs. It is also of clinical, academic and scientific interest to obtain brain electrical maps from old paper/ink, patient recordings. The aim of the present study was the development of a computer system designed to obtain bidimensional and tridimensional maps, continuous movie map display and mosaic presentation from conventional paper/ink EEG recordings. The wave amplitude was manually measured with a translucent template from conventional 8- to 16-channel EEG paper recordings using 10-20 monopolar montage for one or both hemispheres. The computer system allows the selection of the number and location of electrodes, input of amplitude values, and the map display mode. The electrical brain field was generated from amplitude measurements by a spherical splines interpolation algorithm on a conventional Pentium-based computer. The interpolated surface was represented on a semi-sphere modeled skull. The EEG maps displayed with pseudo-color or gray scales can be rotated, zoomed in or zoomed out and/or printed for clinical reports. Movie animation or mosaic display of space-temporal EEG voltage changes were generated by processing sequential amplitude measurements. This system represents a cost-effective method for EEG mapping from conventional paper/Ink EEG equipments.
Scientists chart course for brain map.
Explore the source record for details and available documents.
A three-dimensional multimodality brain map of the nemestrina monkey.
A three-dimensional multimodality computerized map of the nemestrina monkey brain was created with serial sectioning and digital imaging techniques. An adult female Macaca nemestrina (pigtail macaque) weighing 7.2 kg was used in constructing this atlas. CT, PET, and MRI were performed on the monkey before the specimen's head was frozen and cryoplaned. Closely spaced (50 microns) images of the specimen blockface were then digitally acquired and modified to produce whole head and brain-only 3D image sets. The resulting data sets were organized into a digital volume and repositioned into a stereotaxic coordinate system defined by Horsley and Clark in 1908 [7]. Orthogonal images were obtained by digitally resampling the volume in order to produce a full set of coronal, sagittal, and horizontal images. Stereotaxic reference grids were applied to each image indicating the A/P, M/L, or Ho position within the digital volume. Specific anatomic structures were outlined from the cryosection data set and 3D surface models reconstructed. Structural labels indicating nuclei, tracts, and other neuroanatomical features were incorporated into coronally sliced cryosection images spaced at 500 microns. The CT, PET, and MRI data sets were reconstructed into a digital volume and coregistered to the cryosection volume. All images constructed from this 3D map are available for public access via the internet using an anonymous file transfer protocol (FTP) and the World Wide Web (http:@www.loni.ucla.edu). The foremost advantage of this digital map is an integrated multimodality three-dimensional representation of the Macaca nemestrina brain, which is not possible with traditional atlases.
Endogenous melanocortin antagonist in fish: structure, brain mapping, and regulation by fasting of the goldfish agouti-related protein gene.
Agouti-related protein (AGRP) is a naturally occurring antagonist of melanocortin. In mammals, central AGRP expression is restricted to the arcuate nucleus in which it plays a key role in the control of energy balance by antagonizing melanocortin effects at melanocortin 4 receptors. In goldfish, melanocortin 4 receptor is profusely expressed within the main brain areas for the control of energy balance, and central administration of agonist or antagonist analogs inhibits or stimulates food intake, respectively. Here we demonstrate that the goldfish genome has a homologous gene to mammalian AGRP. Detailed brain mapping by in situ hybridization shows that AGRP is exclusively expressed in the ventrobasal hypothalamic lateral tuberal nucleus, the teleostean homolog of the arcuate nucleus. Fasting up-regulates its mRNA levels in the lateral tuberal nucleus. In the periphery, AGRP is expressed in several tissues including ovary, muscle, and ventral skin, suggesting that AGRP might regulate peripheral actions of melanocortin peptides. The results provide the first evidence for an endogenous melanocortin antagonist in nontetrapod species and suggest that hypothalamic overexpression during fasting might regulate the inhibitory effects of melanocortin peptides on food intake in goldfish.
Abnormalities of thalamic volume and shape detected in fetally irradiated rhesus monkeys with high dimensional brain mapping.
BACKGROUND: Prior research has indicated neuroanatomical abnormalities of the thalamus in schizophrenia. To study the possible pathogenesis, an animal model of neurodevelopmental thalamic damage has been developed by applying low-dose radiation to rhesus monkeys in early gestation. Irradiated monkeys sacrificed as infants demonstrate neuronal losses in specific thalamic nuclei and decreases in cortical neuropil. METHODS: Magnetic resonance scans were collected in adult Rhesus monkeys exposed to irradiation during thalamic neurogenesis (E33-42), after thalamic neurogenesis (E70-81), and in nonirradiated control animals. High dimensional brain mapping was used to compare thalamic volumes and shape characteristics in the three groups of animals. RESULTS: Animals exposed to irradiation at E33-42 showed a significant bilateral loss of thalamic volumes (> 20%) compared with controls and with animals irradiated at E70-81 when total brain volume was used as a covariate in the analysis. Thalamic volume loss was associated with a nonuniform deformation of thalamic shape. CONCLUSIONS: A first-trimester, neurodevelopmental insult in the nonhuman primate during thalamic neurogenesis produces a complex pattern of thalamic volume loss and shape deformation in adulthood. Low-dose irradiation of the fetal primate may be useful for modeling key features of the pathology described in schizophrenic patients.
Extensive brain mapping of calcitonin-induced anorexia.
The purpose of this study was to compare the localization in the brain of calcitonin-induced anorexia to the distribution of calcitonin binding sites (as described by others). We, thus, performed an extensive mapping of brain structures to determine those involved in calcitonin-induced anorexia. A significant anorexia is found after injection of calcitonin (15 ng in 0.3 microliters) into several brain areas. Forebrain: lateral septum, lateral part of the anterior commissure, and bed nucleus of the stria terminalis; hypothalamus: floor of the anterior part of the hypothalamus, paraventricular nucleus and adjacent perifornical area; thalamus: nucleus reuniens, an area internal to the mamillo-thalamic tract, and medial geniculate body; other areas: amygdala, lateral hippocampus, and central gray. No significant effect is found in the following areas: forebrain: nucleus accumbens, striatum, and medial septum; hypothalamus: lateral, ventro-medial, dorso-medial, and posterior nuclei; thalamus: centro-medial nucleus, lateral part of the zona incerta, and lateral geniculate body; hippocampus: dorsal and ventral parts; midbrain: central tegmentum, ventral tegmental area, and substantia nigra. When these results are compared to the distribution of calcitonin binding sites in the brain, two types of discrepancies are found. The first is the absence of effect in areas containing receptors: these areas may be involved in calcitonin-induced behaviors other than food intake. The second is the occurrence of anorexia in areas where no receptors are found: this finding is not easy to explain and raises some speculative hypotheses. In conclusion, calcitonin is active to decrease food intake in several brain areas, the strongest effect occurring in the paraventricular/perifornical area.(ABSTRACT TRUNCATED AT 250 WORDS)
Receptors for interleukin-1 (alpha and beta) in mouse brain: mapping and neuronal localization in hippocampus.
Interleukin-I receptors were mapped and characterized in mouse brain by quantitative autoradiography using human recombinant [125I]interleukin-I alpha and [125I]interleukin-1 beta as ligands. Both ligands provide identical receptor mapping. In terms of specificity, interleukin-1 alpha and interleukin-1 beta were equally potent in binding competitions assays with either [125I]interleukin-1 alpha or [125I]interleukin-1 beta (EC50 11 pM). These receptors were shown to be highly concentrated in the dentate gyrus, in the choroid plexus at various levels of the brain, in the pituitary and in the meninges. They were also present at low concentrations in the cortex but undetectable in other brain structures. In the dentate gyrus, interleukin-1 receptors were localized on the granular and molecular layers (granule cells) when visualized on slides dipped in nuclear emulsion. Cellular localization of interleukin-1 receptors was assessed using selective lesion by colchicine. The complete loss of [125I]interleukin-1 binding in hippocampal areas where neurons were destroyed by colchicine demonstrates that interleukin-1 receptors are located on granule cells. Following lesion, sparse undestroyed cells, with glial cell morphology, also showed significant labelling. In conclusion, interleukin-1 receptors are located on the granule cells in the mouse dentate gyrus. These neurons may therefore be targets for neuromodulation by interleukin-1 and they may play a key role in the central effect of interleukin-1 as well as in the control of the immune response by the brain.
Multivariate statistical brain electromagnetic mapping.
Brain Electromagnetic Topography (BET) has attained widespread use. The representation of EEG or MEG parameters as scalp maps (BETm) aids its clinical interpretation. However, some critical issues limit the usefulness of BETm. In particular, the conventional statistical assessment of BETm with respect to normative data is based upon marginal significance probability scales which involve multiple univariate comparisons (one at each recording site). As a consequence, the probability of false positive findings (type I error) is increased above its nominal level. The use of conservative levels avoids this phenomenon but results in a considerable increase of the probability of not detecting real abnormality (type II error). Furthermore, BETm are constructed without taking into consideration the patterns of correlations characteristic of electromagnetic data under normal states of brain functioning. This limits the capability of BETm of representing multivariate aspects of abnormality. This paper introduces some techniques to approach these difficulties. Multivariate Brain Electromagnetic Topographic maps (MBETm) are defined, which retain the attractive features of mapping but also take advantage of multivariate characteristics (in the spatial and frequency domains) to highlight aspects of neuropathology. Moreover, simultaneous significance probability (SSP) scales, valid for both BETm and MBETm, are introduced for the global control of the probability of a type I error. The use of these techniques is illustrated with data from patients with cortical tumours and with epilepsy. ROC analysis shows that in some cases there is a significant improvement in both detection and localization accuracy.
Quantitative EEG Brain Mapping In Psychotropic Drug Development, Drug Treatment Selection, and Monitoring.
Quantification of standard electroencephalogram (EEG) by digital computers [computer-analyzed EEG (CEEG)] has transformed the subjective analog EEG into an objective scientific method. Until a few years ago, CEEG was only used to assist in the development of psychotropic drugs by means of the quantitative pharmaco EEG. Thanks to the computer revolution and the accompanying reductions in cost of quantification, CEEG can now also be applied in psychiatric practice. CEEG can assist the physician in confirming clinical diagnoses, selecting psychotropic drugs for treatment, and drug treatment monitoring. Advancements in communications technology allow physicians and researchers to reduce the costs of acquiring a high-technology CEEG brain mapping system by utilizing the more economical telephonic services.
[Comments on the analysis of the P300 components using brain mapping].
Recently, Maurer and colleagues reported that the peak amplitude of the P300 was distributed in specific topographical patterns for demented, hebephrenic, and paranoid patients. This evidence is critically discussed. For the hebephrenic and paranoid patients, it is doubtful whether their topographic patterns differed from normal subjects, while for the demented patients the impact of EOG artifacts is not clear. Some recommendations are given how to deal with artifacts before mapping the P300.
Variability and asymmetry in the human precentral motor system. A cytoarchitectonic and myeloarchitectonic brain mapping study.
The morphology of the region of the primary motor cortex in the human brain is variable, and putative asymmetries between the hemispheres have been noted since the beginning of last century. Such variability may confound the results of clinical lesion or functional activation studies. We measured Brodmann area (BA) 4 and the identifiable precentral component of the pyramidal tract (PRPT) in 11 human post-mortem brains using techniques of quantitative cytoarchitectonic and myeloarchitectonic image analysis. Topography and variability in the localization of architectonic borders were analysed and mapped to a computerized spatial reference system, which consists of an individual in vivoMRI brain. All maps were superimposed to produce probabilistic maps of BA 4 and PRPT which can be co-registered with any image of brain structure or function that has also been transformed to Talairach coordinates. These maps can be readily applied to future brain mapping studies. We observed a considerable degree of variability between hemispheres (intra-individual) and between brains (inter-individual). The variation zones of BA 4 and PRPT differ from the templates of the Talairach atlas. Voxel-based morphometry shows significant side differences with larger volumes of PRPT in the left hemisphere than in the right hemisphere. This larger volume of the descending cortical motor fibres may be related to the known left-hemisphere dominance for handedness in >90% of the population. In contrast, BA 4 was symmetrically organized. The lack of a significant correlation between the size of BA 4 and the size of PRPT may relate to the fact that additional non-primary motor and sensory cortices contribute to the origins and size of the pyramidal tract proper.
[Quantitative and topographic EEG brain mapping: a study of normal adult population].
We studied the electric brain activity during wakefulness in 20 Brazilian people through digital EEG and spectral analysis in order to propose a standardization for Brazilian adult population. All this group is healthy with laboratory examinations and mini-mental state (scores higher than 27) evaluation normal. After Fourier fast transformation (FFT) calculation, we found a histogram display with monomodal distribution, with higher values in alpha band. Analyzing the average of these results, different standards from the analogical traditional EEG were found, as the distribution of alpha band and delta activity behavior. The beta 2 and beta 3 behavior showed a diffuse distribution, that is not the usual. By the other hand, other findings are congruent to the analogical EEG as the alpha posterior predominance and the bigger presence of theta activity at the central regions.