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You searched for subject:(Parahippocampus). Showing records 1 – 3 of 3 total matches.

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University of Florida

1. Parekh, Mansi. Enhanced Magnetic Resonance Imaging of a Rat Model of Temporal Lobe Epilepsy.

Degree: PhD, Medical Sciences - Neuroscience (IDP), 2010, University of Florida

Enhanced Magnetic Resonance Imaging of a Rat Model of Temporal Lobe Epilepsy Structural changes in limbic regions are often observed in individuals with temporal lobe epilepsy (TLE) and in animal models of TLE. However, the brain structural changes during the evolution into epilepsy remain largely unknown. Therefore, the purpose of this study was to define the temporal changes in limbic structures during the latency period of epileptogenesis in vivo, after electrically induced experimental status epilepticus (SE), with quantitative diffusion tensor imaging (DTI) and T2 relaxometry in an animal model of chronic TLE. A pair of fifty micron electrodes was implanted into the ventral hippocampus in male adult rats. In vivo diffusion tensor and T2 magnetic resonance imaging (MRI) was performed at 11.1 Tesla (T), pre- and post-implantation of electrodes and 1, 3, 5, 7, 10, 20, 40 and 60 days post-SE to assess structural changes. Spontaneous seizures were identified with continuous time-locked video monitoring. Following imaging in vivo, fixed, excised brains were MR imaged at 17.6 T. Subsequently, histological analysis was correlated with MRI results. Following SE, 8/11 injured rats developed spontaneous seizures. Unique to only 8 of 11 rats, early T2, diffusivity and anisotropy changes were observed in vivo within the parahippocampal gyrus (contralateral) and fimbria (bilateral). In excised brains, bilateral increase in anisotropy was observed in the dentate gyrus, corresponding to mossy fiber sprouting as determined by Timm staining. The other three rats did not show any such changes and did not develop spontaneous seizures, despite the same initial injury (i.e. SE). Based on the results of this initial study, a cohort of rats was perfused at days 1, 3 and 10 to study the early pathological changes and correlate in vivo MR changes with excised imaging and histology. Three rats were perfused at day 1 and 3 post-SE each and two rats were perfused at day 10 post-SE. Extensive neurodegeneration was observed bilaterally in the hippocampus and in the contralateral parahippocampal gyrus. Extensive microglial activation and gliosis were also observed in the same regions at day 3 post-SE. No correlation was observed with decreased average diffusivity (AD) and cellular swelling within the pyramidal cell layers of the hippocampus. At day-10 post-SE gliosis was observed in the same regions but there was reduction in FJC-stained degenerating neurons. Interestingly, similar to all rats that developed spontaneous seizures, these early time-point rats also showed substantial damage in the amygdala, piriform cortex and the entorhinal cortex. Therefore, based on these results, it can be postulated that aberrant connectivity between the parahippocampal gyrus and the hippocampus may be of importance in the onset of spontaneous seizures. Future work would include studying the connectivity between these regions. Preliminary studies show that the perforant pathway (connections between the entorhinal cortex and the dentate gyrus) may be fiber… Advisors/Committee Members: Mareci, Thomas H. (committee chair), King, Michael A. (committee member), Liu, Zhao (committee member), Sarntinoranont, Malisa (committee member).

Subjects/Keywords: Amygdala; Animal models; Dentate gyrus; Entorhinal cortex; Epilepsy; Hippocampus; Imaging; Parahippocampal gyrus; Rats; Seizures; dti, epilepsy, epileptogenesis, fibertracking, hippocampus, mri, parahippocampus

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Parekh, M. (2010). Enhanced Magnetic Resonance Imaging of a Rat Model of Temporal Lobe Epilepsy. (Doctoral Dissertation). University of Florida. Retrieved from https://ufdc.ufl.edu/UFE0042161

Chicago Manual of Style (16th Edition):

Parekh, Mansi. “Enhanced Magnetic Resonance Imaging of a Rat Model of Temporal Lobe Epilepsy.” 2010. Doctoral Dissertation, University of Florida. Accessed December 04, 2020. https://ufdc.ufl.edu/UFE0042161.

MLA Handbook (7th Edition):

Parekh, Mansi. “Enhanced Magnetic Resonance Imaging of a Rat Model of Temporal Lobe Epilepsy.” 2010. Web. 04 Dec 2020.

Vancouver:

Parekh M. Enhanced Magnetic Resonance Imaging of a Rat Model of Temporal Lobe Epilepsy. [Internet] [Doctoral dissertation]. University of Florida; 2010. [cited 2020 Dec 04]. Available from: https://ufdc.ufl.edu/UFE0042161.

Council of Science Editors:

Parekh M. Enhanced Magnetic Resonance Imaging of a Rat Model of Temporal Lobe Epilepsy. [Doctoral Dissertation]. University of Florida; 2010. Available from: https://ufdc.ufl.edu/UFE0042161


Brunel University

2. Shaw, Lynda Joan. Emotional processing of natural visual images in brief exposures and compound stimuli : fMRI and behavioural studies.

Degree: PhD, 2009, Brunel University

Can the brain register the emotional valence of brief exposures of complex natural stimuli under conditions of forward and backward masking, and under conditions of attentional competition between foveal and peripheral stimuli? To address this question, three experiments were conducted. The first, a behavioural experiment, measured subjective valence of response (pleasant vs unpleasant) to test the perception of the valence of natural images in brief, masked exposures in a forward and backward masking paradigm. Images were chosen from the International Affective Picture System (IAPS) series. After correction for response bias, responses to the majority of target stimuli were concordant with the IAPS ratings at better than chance, even when the presence of the target was undetected. Using functional magnetic resonance imaging (fMRI), the effects of IAPS valence and stimulus category were objectively measured on nine regions of interest (ROIs) using the same strict temporal restrictions in a similar masking design. Evidence of affective processing close to or below conscious threshold was apparent in some of the ROIs. To further this line of enquiry, a second fMRI experiment mapping the same ROIs and using the same stimuli were presented in a foveal (‘attended’) peripheral (‘to-be-ignored’) paradigm (small image superimposed in the centre of a large image of the same category, but opposite valence) to investigate spatial parameters and limitations of attention. Results are interpreted as showing both valence and category specific effects of ‘to-be-ignored’ images in the periphery. These results are discussed in light of theories of the limitations of attentional capacity and the speed in which we process natural images, providing new evidence of the breadth of variety in the types of affective visual stimuli we are able to process close to the threshold of conscious perception.

Subjects/Keywords: 612.8; Amygdala; Anterior Cingulate Cortex; medial Prefrontal Cortex; Dorsolateral Prefrontal Cortex; Orbitofrontal Cortex; Parahippocampus; Fusiform Gyrus; Insula; Superior Temporal Gyrus; consciousness; attention; masking; fMRI

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Shaw, L. J. (2009). Emotional processing of natural visual images in brief exposures and compound stimuli : fMRI and behavioural studies. (Doctoral Dissertation). Brunel University. Retrieved from http://bura.brunel.ac.uk/handle/2438/3203 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.557697

Chicago Manual of Style (16th Edition):

Shaw, Lynda Joan. “Emotional processing of natural visual images in brief exposures and compound stimuli : fMRI and behavioural studies.” 2009. Doctoral Dissertation, Brunel University. Accessed December 04, 2020. http://bura.brunel.ac.uk/handle/2438/3203 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.557697.

MLA Handbook (7th Edition):

Shaw, Lynda Joan. “Emotional processing of natural visual images in brief exposures and compound stimuli : fMRI and behavioural studies.” 2009. Web. 04 Dec 2020.

Vancouver:

Shaw LJ. Emotional processing of natural visual images in brief exposures and compound stimuli : fMRI and behavioural studies. [Internet] [Doctoral dissertation]. Brunel University; 2009. [cited 2020 Dec 04]. Available from: http://bura.brunel.ac.uk/handle/2438/3203 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.557697.

Council of Science Editors:

Shaw LJ. Emotional processing of natural visual images in brief exposures and compound stimuli : fMRI and behavioural studies. [Doctoral Dissertation]. Brunel University; 2009. Available from: http://bura.brunel.ac.uk/handle/2438/3203 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.557697


Université de Montréal

3. Chebat, Daniel-Robert. Un oeil sur la langue : aspects neuro-cognitifs du processus de la navigation chez l'aveugle-né.

Degree: 2010, Université de Montréal

Subjects/Keywords: Plasticité intermodale; aveugle de naissance; substitution sensorielle; navigation; détection et contournement d'obstacles; IRMf; environnement virtuel; hippocampe; parahippocampe; cortex visuel; humain; Cross-modal plasticity; Early blind; sensory substitution; virtual environment; hippocampus; parahippocampus; visual cortex; human; Psychology - Experimental / Psychologie expérimentale (UMI : 0623)

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Chebat, D. (2010). Un oeil sur la langue : aspects neuro-cognitifs du processus de la navigation chez l'aveugle-né. (Thesis). Université de Montréal. Retrieved from http://hdl.handle.net/1866/4421

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Chebat, Daniel-Robert. “Un oeil sur la langue : aspects neuro-cognitifs du processus de la navigation chez l'aveugle-né.” 2010. Thesis, Université de Montréal. Accessed December 04, 2020. http://hdl.handle.net/1866/4421.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Chebat, Daniel-Robert. “Un oeil sur la langue : aspects neuro-cognitifs du processus de la navigation chez l'aveugle-né.” 2010. Web. 04 Dec 2020.

Vancouver:

Chebat D. Un oeil sur la langue : aspects neuro-cognitifs du processus de la navigation chez l'aveugle-né. [Internet] [Thesis]. Université de Montréal; 2010. [cited 2020 Dec 04]. Available from: http://hdl.handle.net/1866/4421.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chebat D. Un oeil sur la langue : aspects neuro-cognitifs du processus de la navigation chez l'aveugle-né. [Thesis]. Université de Montréal; 2010. Available from: http://hdl.handle.net/1866/4421

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.