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Full-Text Articles in Medicine and Health Sciences

Intrinsic Features Of The Multisensory Cortical Area Lrss In The Ferret, Alexandru Ioan Cojanu Nov 2010

Intrinsic Features Of The Multisensory Cortical Area Lrss In The Ferret, Alexandru Ioan Cojanu

Theses and Dissertations

Environmental events simultaneously transduced by more than one sensory modality underlie multisensory processing in the CNS. While most studies of multisensory processing examine functional effects, none have evaluated the influence of local or columnar circuitry. The goal of the present study is to examine of local features of the ferret lateral rostral suprasylvian sulcus (LRSS), a multisensory cortex. Immunostaining revealed the cytoarchitectonic features of the LRSS: thick supragranular layers, a narrow layer IV, and moderately stained but differentiated infragranular layers. Golgi-Cox techniques were used with light microscopy and digital reconstruction to document neuronal morphology. Among the 90 reconstructed neurons, 4 …


Volumetric Growth Model Of Human Medulloblastoma In The Nude Mouse Cerebellum, Thomas Gavigan Aug 2010

Volumetric Growth Model Of Human Medulloblastoma In The Nude Mouse Cerebellum, Thomas Gavigan

Theses and Dissertations

Medulloblastoma is the most common brain tumor in children, accounting for 10-20% of primary central nervous system (CNS) neoplasms and approximately 40% of all posterior fossa tumors. It is a highly invasive embryonal neuroepithelial tumor that typically arises in the cerebellar vermis and has a tendency to disseminate throughout the CNS early in its course. The molecular mechanisms of the disease largely remain uncharacterized, as the clinical treatment is still associated with mortality and severe side effects. The development of a clinically relevant in vivo model is important not only to further understand the disease but also to provide a …


Novel Roles For Reelin In Retinogeniculate Targeting, Cheryl Haner Aug 2010

Novel Roles For Reelin In Retinogeniculate Targeting, Cheryl Haner

Theses and Dissertations

In the developing visual system, the axon of a pre-synaptic cell must be guided to a post-synaptic partner. Retinal ganglion cells (RGCs) in the eye are an excellent model to study this process. Multiple classes exist that respond to specific types of light input, and these project to different destinations in the brain that process distinct types of information. The RGC axons that navigate to the lateral geniculate nucleus (LGN) do so in a class-specific manner. Axons from RGCs that mediate non-image forming functions innervate the ventral LGN (vLGN) and the intergeniculate leaflet (IGL). Axons from RGCs that process image-forming …


Klf2/Klf4 Double Knock-Out Mouse Embryos Show Cranial Bleeding With Endothelial Disruption Of The Primary Head Vein, Benjamin Curtis Aug 2010

Klf2/Klf4 Double Knock-Out Mouse Embryos Show Cranial Bleeding With Endothelial Disruption Of The Primary Head Vein, Benjamin Curtis

Theses and Dissertations

Krüppel-like factors (KLFs) are a family of 3 Cys2/His2 zinc finger transcription factors with a diverse set of roles in cellular differentiation, cell cycle regulation, tumor suppression, erythropoiesis, angiogenesis, and other processes. During embryonic development, KLF2 has a role in vessel maturation. Adult conditional KLF4 knockout mouse embryos have thickened arterial intima follow vascular injury. Breeding KLF2+/- and KLF4+/- mice resulted in the generation of KLF2/KLF4 double knockout (DKO) embryos. KLF2/KLF4 DKO embryos died by E10.5 with cranial bleeding. Using immunohistochemistry, embryo whole-mounts were examined for differences in gross vascularization between wild-type (WT), KLF2-/- and KLF2/KLF4 (DKO embryonic day 9.5 …


Membrane-Bound Matrix Metalloproteinases Influence Reactive Synaptogenesis Following Traumatic Brain Injury, Kelly Warren Jul 2010

Membrane-Bound Matrix Metalloproteinases Influence Reactive Synaptogenesis Following Traumatic Brain Injury, Kelly Warren

Theses and Dissertations

Traumatic brain injury (TBI) produces axonal damage and deafferentation, triggering injury-induced synaptogenesis, a process influenced by matrix metalloproteinases (MMP) and their substrates. Here we report results of studies examining the expression and potential role of two membrane-bound MMPs, membrane-type 5-MMP (MT5-MMP) and a disintegrin and metalloproteinase-10 (ADAM-10), along with their common synaptic substrate N-cadherin, during the period of reactive synaptogenesis. Protein and mRNA expression of MT5-MMP, ADAM-10 and N-cadherin were compared in two TBI models, one exhibiting adaptive plasticity (unilateral entorhinal cortex lesion; UEC) and the other maladaptive plasticity (fluid percussion injury + bilateral EC lesions; TBI+BEC), targeting 2, 7, …


Regional Heterogeneity And Diversity Of Astrocytes In Response To Hiv-1 Proteins And Morphine, Wen Chen Jun 2010

Regional Heterogeneity And Diversity Of Astrocytes In Response To Hiv-1 Proteins And Morphine, Wen Chen

Theses and Dissertations

HIV-infected individuals who abuse opiates have been found to have a higher incidence and a faster progression of HIV encephalitis. Astrocytes, the major support cells in the CNS, are known to play a critical role in the HIV neuropathy. Although astrocytes tend not to be productively infected by the HIV-1 virus, dysregulation of their pro- and anti- inflammatory cytokines/chemokines secretion is usually neurotoxic. Glutamate transport in astrocytes is reported to be impaired as well, which result in extrasynaptic excitatory neurotransmitter accumulation and over stimulation of postsynaptic neurons. It is long known that astrocytes from different brain regions have diverse responses …


The Effects Of Bfgf Treatment In The Aged Brain Following Traumatic Brain Injury, Michael Zeigler Jun 2010

The Effects Of Bfgf Treatment In The Aged Brain Following Traumatic Brain Injury, Michael Zeigler

Theses and Dissertations

The mature mammalian brain continually generates new neurons in the subventricular zone and hippocampus throughout life. Adult neurogenesis in the hippocampus is associated with hippocampal-dependent learning and memory function. During aging, this endogenous neurogenic potential is reduced which is accompanied by decreased cognitive function seen in the aging population. We have previously found that the injured adult brain shows heightened levels of endogenous neurogenesis and this response is associated with innate cognitive recovery. We have also found that basic fibroblast growth factor (bFGF), a potent neurotrophic polypeptide, can enhance injury-induced hippocampal neurogenesis and improve cognitive recovery following TBI. In this …


Spinal Cord Injury: Exploring The Histology Of Electrospun Implants In Vivo, Charles Lin May 2010

Spinal Cord Injury: Exploring The Histology Of Electrospun Implants In Vivo, Charles Lin

Theses and Dissertations

Spinal cord injury results in loss of motor function and sensory perception. A myriad of obstacles prevent axonal regeneration and ultimately functional recovery in those afflicted with spinal cord injury. Combinatorial strategies addressing many of these obstacles simultaneously have shown promising results. Laboratories investigating contusional spinal cord injuries must overcome the formation of a fluid filled cyst, a physical gap that axons must traverse, at the injury epicenter. To fill the cyst, our lab has generated a 3-D electrospun matrix that is capable of directing neurite outgrowth, delivering neurotrophic support, and reducing the activity of neuroinhibitory compounds. These electrospun matrices …


Focal Adhesion Kinase, A Major Regulator Of Oligodendrocyte Morphological Maturation And Myelination, Audrey Lafrenaye Apr 2010

Focal Adhesion Kinase, A Major Regulator Of Oligodendrocyte Morphological Maturation And Myelination, Audrey Lafrenaye

Theses and Dissertations

The formation of the myelin sheath is a crucial step during development because it enables fast and efficient propagation of signals within the limited space of the mammalian central nervous system. During the process of myelination, oligodendrocytes actively interact with the extracellular matrix (ECM). These interactions are considered crucial for proper and timely completion of the myelin sheath. However, the exact regulatory circuits involved in the signaling events that occur between the ECM and oligodendrocytes are currently not fully understood. Therefore, in this dissertation we investigated the role of a known integrator of cell-ECM signaling, namely, focal adhesion kinase (FAK), …


Perifosine, A Novel Akt Inhibitor Induces Apoptosis, Cell Cycle Arrest And Has A Chemo-Sensitizing Effect In Medulloblastoma Cell Lines, Anil Kumar Apr 2010

Perifosine, A Novel Akt Inhibitor Induces Apoptosis, Cell Cycle Arrest And Has A Chemo-Sensitizing Effect In Medulloblastoma Cell Lines, Anil Kumar

Theses and Dissertations

Primary central nervous system (CNS) tumors are the most common solid tumors found in children. While surgery and radiotherapy still remain the standard treatment modalities in pediatric brain tumors, chemotherapy also has an important part in the management of these tumors. However, most of the available chemotherapeutic drugs have suboptimal effectiveness. Deregulation of various pro-apoptotic and anti-apoptotic pathways has been cited as a major mechanism underlying this drug resistance. The role of various serine threonine kinases, including Akt kinases, in promoting drug resistance is being extensively studied in various cancers. A complete understanding of the molecular mechanisms that underlie drug …


The Influences Of Matrix Metalloproteinase-1 Expression On Glioblastoma Pathology, Nicholas Pullen Mar 2010

The Influences Of Matrix Metalloproteinase-1 Expression On Glioblastoma Pathology, Nicholas Pullen

Theses and Dissertations

Glioblastoma multiforme (GBM) is an aggressive central nervous system (CNS) cancer characterized by enhanced tumor cell motility, pernicious invasion into the normal brain, extensive tumor-induced angiogenesis, and adaptive resistance to current therapeutic paradigms. One of the difficulties associated with GBM is the ability of the tumor cells to infiltrate normal CNS tissue. Neurosurgeons can remove the primary tumor mass, but peripheral cells that are inaccessible will ultimately result in a secondary lesion that can lead to death. The matrix metalloproteinases (MMP) are well known for their abilities to facilitate processes of cellular motility and invasion through their clearance of extracellular …


Dendritic Spine Density Varies Between Unisensory And Multisensory Cortical Regions, Moazzum Bajwa Jan 2010

Dendritic Spine Density Varies Between Unisensory And Multisensory Cortical Regions, Moazzum Bajwa

Theses and Dissertations

In the brain, the dendritic spine is a point of information exchange that extends the neuronal surface on which synapses occur, as well as facilitates and stabilizes those contacts. Furthermore, dendritic spines dynamically change in shape and number in response to a variety of factors. Dendritic spine numbers are reduced in mental retardation, enhanced during development, sensory enrichment or physical exercise, or fluctuate during the reproductive cycle. Thus, for a given neuron type, it might be expected that dendritic spine number might achieve a dynamic optimum. Indeed, many studies of spine density of pyramidal neurons in sensory cortex indicate that …