Visualization-Based Mapping of Language Function in the Brain

Cortical language maps, obtained through intraoperative electrical stimulation studies, provide a rich source of information for research on language organization. Previous studies have shown interesting correlations between the distribution of essential language sites and such behavioral indicators as verbal IQ and have provided suggestive evidence for regarding human language cortex as an organization of multiple distributed systems. Noninvasive studies using ECoG, PET, and functional MR lend support to this model; however, there as yet are no studies that integrate these two forms of information. In this paper we describe a method for mapping the stimulation data onto a 3-D MRI-based neuroanatomic model of the individual patient. The mapping is done by comparing an intraoperative photograph of the exposed cortical surface with a computer-based MR visualization of the surface, interactively indicating corresponding stimulation sites, and recording 3-D MR machine coordinates of the indicated sites. Repeatability studies were performed to validate the accuracy of the mapping technique. Six observers—a neurosurgeon, a radiologist, and four computer scientists, independently mapped 218 stimulation sites from 12 patients. The mean distance of a mapping from the mean location of each site was 2.07 mm, with a standard deviation of 1.5 mm, or within 5.07 mm with 95% confidence. Since the surgical sites are accurate within approximately 1 cm, these results show that the visualization-based approach is accurate within the limits of the stimulation maps. When incorporated within the kind of information system envisioned by the Human Brain Project, this anatomically based method will not only provide a key link between noninvasive and invasive approaches to understanding language organization, but will also provide the basis for studying the relationship between language function and anatomical variability

Neuronal correlates of functional magnetic resonance imaging in human temporal cortex

The relationship between changes in functional magnetic resonance imaging and neuronal activity remains controversial. Data collected during awake neurosurgical procedures for the treatment of epilepsy provided a rare opportunity to examine this relationship in human temporal association cortex. We obtained functional magnetic resonance imaging blood oxygen dependent signals, single neuronal activity and local field potentials from 8 to 300 Hz at 13 temporal cortical sites, from nine subjects, during paired associate learning and control measures. The relation between the functional magnetic resonance imaging signal and the electrophysiologic parameters was assessed in two ways: colocalization between significant changes in these signals on the same paired associate-control comparisons and multiple linear regressions of the electrophysiologic measures on the functional magnetic resonance imaging signal, across all tasks. Significant colocalization was present between increased functional magnetic resonance imaging signals and increased local field potentials power in the 50–250 Hz range. Local field potentials power greater than 100 Hz was also a significant regressor for the functional magnetic resonance imaging signal, establishing this local field potentials frequency range as a neuronal correlate of the functional magnetic resonance imaging signal. There was a trend for a relation between power in some low frequency local field potentials frequencies and the functional magnetic resonance imaging signal, for 8–15 Hz increases in the colocalization analysis and 16–23 Hz in the multiple linear regression analysis. Neither analysis provided evidence for an independent relation to frequency of single neuron activity

Mechanisms Underlying Alcohol-Mediated Cellular Injury In Esophageal Keratinocytes

Esophageal squamous cell carcinoma (ESCC) is the 6th deadliest cancers worldwide. Although it is more prevalent in eastern world, it accounts for 90% of esophageal cancer worldwide. Late stage diagnosis and resistance to therapy has resulted in a poor 5-year survival rate of 20%. Alcohol consumption is a major environmental risk factor for developing ESCC. Acetaldehyde, a by-product of alcohol metabolism is a potent human carcinogen. Furthermore, single nucleotide polymorphisms (SNPs) in the alcohol metabolizing enzyme Aldehyde dehydrogenase (ALDH)-2 is strongly associated with ESCC. However, there is very limited understanding underlying the interaction between alcohol and the esophageal epithelium. Here, we utilize in vitro, ex vivo and in vivo models to study alcohol-mediated cellular injury and cytoprotective mechanisms in esophageal keratinocytes. Here we utilize RNA-Seq to identify dramatic decrease in genes and pathways associated with DNA repair and Mitochondria in alcohol exposed human esophageal keratinocytes. Alcohol caused significant structural damage to mitochondria which translated into decreased mitochondrial functional output leading to a combination of metabolic and oxidative stress. Autophagy maintained cell viability and mitochondrial homeostasis under alcohol induced stress. Autophagy induction was accompanied by a simultaneous activation of AMPK and inhibition of mTORC1. Loss of ALDH2 increased the susceptibility of esophageal keratinocytes to alcohol and acetaldehyde mediated toxicity and cell death. Cells were more reliant on autophagy in the absence of ALDH2 to negate alcohol-induced oxidative stress and DNA damage. In summary, the current work offers insight into alcohol-induced metabolic and oxidative stress in esophageal keratinocytes as the potential source of cellular injury. Finally, autophagy could be a key cytoprotective pathway in modulating response to alcohol-induced stress

3D Matching using Statistically Significant Groupings

Vision programming is defined as the task of constructing explicit object models to be used in object recognition. These object models specify the features to be used in recognizing the object as well as the exact order in which they have to be used. For 3D recognition, in the absence of grouping information, the number of bases (model feature/image feature correspondences) that must be examined before a match is found is prohibitively large. By exploiting the relationships between features, we can avoid having to consider a potentially large number of bases. The automatic programming framework [5] helps us in ordering model features based on their utilities such as detectability and error rate that are derived from training data. Examining model features in the order specified by this framework leads to minimal numbers of bases being considered before a match is found. In this article, we describe a vision programming approach to matching 3D models to 2D images. Our system considers feature clusters instead of individual features..

A Web-based repository manager for brain mapping data.

The Web provides a rapid prototyping environment for building platform-independent graphical user interfaces. A Web-based console can be implemented as a suite of CGI scripts that generate HTML code, manipulate files, execute system commands, and invoke external tools. Often these tools share data by reading and writing flat files, which must be explicitly maintained by the CGI programmer. In a repository system, meta-data about each file object are maintained in a database, and access to all data is regulated by a layer of control services. This paper describes the design and implementation of a Web-based Repository Manager (WRM), which provides an application programmer's interface for controlling applications, generating HTML documents, handling Web forms, and managing multi-media data. The WRM is being used to develop a console for the Brain Mapping Framework, a system for visualizing cortical stimulation data obtained during neurosurgery

Evaluation of a visualization-based approach to functional brain mapping.

We describe a method for mapping stimulation data, obtained at the time of neurosurgery for intractable epilepsy, onto a 3D MRI-based neuroanatomic model of the individual patient. The mapping is done by comparing an intraoperative photograph of the exposed cortical surface with a computer-based MR visualization of the surface, interactively indicating corresponding stimulation sites, and recording 3-D MR machine coordinates of the indicated sites. Repeatability studies were performed to validate the accuracy of the mapping technique. Six observers--a neurosurgeon, a radiologist, and four computer scientists, independently mapped 218 stimulation sites from 12 patients. The mean distance of the six locations from the mean location of each site was 2.07 mm, with a standard deviation of 1.5 mm, or within 5.07 mm with 95% confidence. Since the surgical sites are accurate within approximately 1 cm, these results show that the visualization-based approach is accurate within the limits of the stimulation maps. When incorporated within the kind of information system envisioned by the Human Brain Project, this anatomically-based method will not only provide a key link between non-invasive and invasive approaches to understanding language organization, but will also provide the basis for studying the relationship between language function and anatomical variability