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Recent human fMRI studies have shown that the hippocampal region is essential for probabilistic category learning, memory formation-retrieval and context based performance. We present an artificial neural network model that can qualitatively simulate the BOLD signal for these tasks. The model offers ideas on the functional architecture and the relationship between the hippocampus and other brain structures...
Delivery of therapeutic compounds to the brain is limited, because due to their molecular size they cannot cross the blood-brain barrier (BBB). Focused ultrasound (FUS) after administration of microbubbles into the blood-stream has been shown to open the BBB locally, non-invasively and reversibly. In this study, we investigated the time required for BBB's permeability at the sonicated region to revert...
The efficacy of uric acid (UA) to prevent cell death and preserve electrophysiological function after traumatic brain injury was tested in an in vitro model. UA significantly reduced post-traumatic cell death and attenuated changes in electrophysiological measures. UA may be a promising novel therapeutic for traumatic brain injury which warrants further study in animal models.
Delayed-nonmatch-to-sample (DNMS) task is memory-dependent. Hippocampal CA3 and CA1 cells were shown to be encoding the required spatial and temporal information to complete this task. In order to identify possible changes in neural population nonlinear dynamics during learning of the DNMS task, we have first modeled the input-output transformation of spike trains across brain subregions from learning...
Brain glucose uptake was examined in transgenic mice relevant to Alzheimer's disease (APP/PS1) and their control littermates (PS1). Glucose distribution in the brain of the resting animals was measured using 3D-reconstructed autoradiography and analysed by a voxel-wise approach using SPMMouse combined to an MRI-based 3D digital atlas. Prompt and direct indexation of metabolic changes between the two...
Epilepsy is a neurological disorder characterized by recurrent seizures which affects about 1% people worldwide. During the past decades, some mechanisms involved in ictogenesis (generation of seizures) have been identified and, to some extent, partially understood. However, regarding epileptogenesis (process by which a neuronal system becomes epileptic), underlying mechanisms remain elusive. This...
This work presents a platform for non-invasive in vitro cell monitoring activity and its use in recording the response of excitable cells to external stimuli. The platform integrates a Microelectrode Array (MEA) device, wire links and connectivity for data acquisitions systems. A MEA chip with platinum electrodes over glass substrate was designed and fabricated in two versions, with and without carbon...
The way that Alzheimer's disease (AD) invades brain is to destroy its fundamental elements, i.e. neurons. The phenomenon of neuron destruction reflects volume changes on brain tissues such as gray matter, white matter and cerebro-spinal fluid. In the AD-related research, the volumetric analysis of hippocampus is the most extensive study. However, the segmentation and identification of the hippocampus...
Hippocampus is one of brain areas which are related with some neurological diseases relating with memory such as Alzheimer and Parkinson. To understand pathogenesis of these diseases requires the development of detailed models of hippocampus function. The CA3 region is one of the most important regions of hippocampus to form associative memory. In this paper, a detailed model of hippocampus CA3 function...
A stimulus on/off imaging study is often used to evaluate the brain's response to a presented visual, electrical or chemical trigger. Clinical software and human templates already exist but given the recent advent of ultrahigh resolution μSPECT and μPET, a larger need rises for a post processing platform to perform these subtraction molecular imaging studies also in small animals. We have designed...
We consider the mechanisms by which coherent activity arises in the hippocampus and entorhinal cortex, two brain areas that are associated with episodic memory in humans and similar forms of memory in animal models. Our approach relies upon techniques from the theory of coupled oscillators. We show that such techniques can yield accurate predictions of the behavior of synaptically coupled neurons...
Traumatic brain injury (TBI) is caused by mechanical forces, producing tissue deformation at the moment of injury. Complex cellular, neurochemical and metabolic alterations are initiated by the deformation and result in delayed cell death and dysfunction. Using an in vitro model of TBI based on organotypic brain slice cultures, we have quantitatively studied the relationship between tissue deformation...
To understand the function of a brain region, e.g., hippocampus, it is necessary to model its input-output property. Such a model can serve as the computational basis of the development of cortical prostheses restoring the transformation of population neural activities performed by the brain region. We formulate a sparse generalized Laguerre-Volterra model (SGLVM) for the multiple-input, multiple-output...
Objective: By analyzing the effect of natural cerebrolysin (NC) on gene expression profile of rat hippocampus Alzheimer's disease (AD), to explore its molecular genetic pharmacodynamic mechanism of anti-AD. Methods: The experiment included the AD model, sham-operation and NC treated group. The changes of hippocampus gene expression profiles in the above three groups were analyzed by Affymetrix rat...
The hippocampus and associative structures are the highest integrative centers in the brain and are known to play a critical role in memory function. To understand how the memory is formed, retrieved and how to reach conscious awareness requires the development of detailed models of hippocampus function and is helpful to study pathogenesis of some brain diseases relating with memory such as Alzheimer...
We propose a general framework for segmentation of subcortical structures and the hippocampus in magnetic resonance brain images based on multi-atlas label propagation and graph cuts. The label maps obtained from multi-atlas segmentation are used to build a subject-specific probabilistic atlas of a structure of interest. From this atlas and an intensity model estimated from the unseen image, a Markov...
The study the age-related changes of hippocampus is an important issue in neuroscience. Here, we established the methodology of analyzing 18F-FDG brain PET images based on functional connectivity, and studied the age-related changes of functional networks in hippocampus detected by this method. 195 healthy volunteers were divided into 4 groups by age and were scanned in a resting state. The functional...
To evaluate normobaric hypoxia-induced brain damage and discuss the mechanism in wistar rat brain injury, the water content of brain , brain infarction area ratio , the level of lactic acid and Na+-K+-ATPase activity were detected. The expression of HIF-lalpha was confirmed using immunohistochemistry. Histopathological changes of brain in rat model due to hypoxia were investigated using hematoxylin...
PingYu capsule was a novel compound botanical drug, being composed of the extracts from Radix et Rhizoma Ginseng, Fructus Jujubae and Radix et Rhizoma Glycyrrhizae, which were the classical herbal medicines in China. Depression is one of psychological and/or physiological disorders. In the recent decades, depression affected the people's health seriously. This study was designed to demonstrate the...
We construct a multi-scale model of shape of surfaces in 3D space based on the heat kernel associated with the Laplace-Beltrami operator. The model is applied to the analysis of longitudinal neuroimaging data collected by the Alzheimer's Disease Neuroimaging Initiative. We use measures of shape deformation energy to quantify, compare and create maps of regional changes in hippocampal shape in normal...
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