Neuroscience and Neurobiology Commons^™

Changes In The Proliferation Of The Subventricular Zone Neural Stem Cell Pool Throughout Aging In The Murine Brain, Olayinka Edwards

Honors Scholar Theses

Previous studies regarding subventricular zone (SVZ) neural stem cells (NSCs) have either observed global changes in the SVZ niche containing NSCs or an impure NSC population. By imaging wholemount preparations of mouse brains and staining with molecular markers specific for proliferating NSC nuclei, the study was able to give a more accurate depiction of the SVZ NSC population than its predecessors. This study will quantify the percentage of proliferating NSCs at various ages of adult murine brain development in order to elucidate a possible correlation between NSC division kinetics and the declining neurogenic output witnessed with aging.

Environmental Influence On Brain, Behavior, And Gene Expression In Drosophila, Xia Wang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Brain development and behavior are sensitive to environmental stimuli. To gain an understanding of how and to what extent environmental variations, particularly with regard to thermal stress and sensory input, affect brain development, function, and genomic activity, in this dissertation, three interrelated studies were conducted in Drosophila melanogaster.

The first study examined the effects of ecologically-relevant hyperthermia stress on development of the Drosophila mushroom body (MB), a conserved sensory integration and associative center in the insect brain. A daily hyperthermic episode throughout larval and pupal development was shown to severely disrupt MB anatomy by reducing intrinsic Kenyon cell neuron …

Characterizing And Treating The Neuropathology Of Tuberous Sclerosis Complex In The Mouse, Sharon W. Way

Dissertations and Theses (Open Access)

Tuberous sclerosis complex (TSC) is a multisystem, autosomal dominant disorder affecting approximately 1 in 6000 births. Developmental brain abnormalities cause substantial morbidity and mortality and often lead to neurological disease including epilepsy, cognitive disabilities, and autism. TSC is caused by inactivating mutations in either TSC1 or TSC2, whose protein products are known inhibitors of mTORC1, an important kinase regulating translation and cell growth. Nonetheless, neither the pathophysiology of the neurological manifestations of TSC nor the extent of mTORC1 involvement in the development of these lesions is known. Murine models would greatly advance the study of this debilitating disorder. This thesis …

Tracking The Flow Of Information Through The Hippocampal Formation In The Rat, Joshua P. Neunuebel

Dissertations and Theses (Open Access)

The hippocampus receives input from upper levels of the association cortex and is implicated in many mnemonic processes, but the exact mechanisms by which it codes and stores information is an unresolved topic. This work examines the flow of information through the hippocampal formation while attempting to determine the computations that each of the hippocampal subfields performs in learning and memory. The formation, storage, and recall of hippocampal-dependent memories theoretically utilize an autoassociative attractor network that functions by implementing two competitive, yet complementary, processes. Pattern separation, hypothesized to occur in the dentate gyrus (DG), refers to the ability to decrease …

Neural Coding Of Temporal Information And Its Topography In The Auditory Cortex, Thomas A. Terleph, Raphael Pinaud

Biology Faculty Publications

The article discusses a study that focused on neural coding of temporal information and topography in the auditory cortex. The quest for a thorough understanding how highly complex stimuli are encoded poses a significant challenge for auditory neurosciences, such as human speech and animal vocal signals. The characteristics of cortical neurons have been attributed to the coding of temporal stimulus which features precise spike timing in the coding and firing rate of repetition sounds.

Meg And Fmri Fusion For Non-Linear Estimation Of Neural And Bold Signal Changes, Sergey M. Plis, Vince D. Calhoun, Michael Patrick Weisend, Tom Eichele, Terran D.R. Lane

Wright State Research Institute Publications

The combined analysis of magnetoencephalography (MEG)/electroencephalography and functional magnetic resonance imaging (fMRI) measurements can lead to improvement in the description of the dynamical and spatial properties of brain activity. In this paper we empirically demonstrate this improvement using simulated and recorded task related MEG and fMRI activity. Neural activity estimates were derived using a dynamic Bayesian network with continuous real valued parameters by means of a sequential Monte Carlo technique. In synthetic data, we show that MEG and fMRI fusion improves estimation of the indirectly observed neural activity and smooths tracking of the blood oxygenation level dependent (BOLD) response. In …

Filtering Of Visual Information In The Tectum By An Identified Neural Circuit, Filippo Del Bene, Claire Wyart, Estuardo Robles, Amanda Tran, Loren Looger, Ethan K. Scott, Ehud Y. Isacoff, Herwig Baier

Neuroscience: Faculty Publications

The optic tectum of zebrafish is involved in behavioral responses that require the detection of small objects. The superficial layers of the tectal neuropil receive input from retinal axons, while its deeper layers convey the processed information to premotor areas. Imaging with a genetically encoded calcium indicator revealed that the deep layers, as well as the dendrites of single tectal neurons, are preferentially activated by small visual stimuli. This spatial filtering relies on GABAergic interneurons (using the neurotransmitter γ-aminobutyric acid) that are located in the superficial input layer and respond only to large visual stimuli. Photo-ablation of these cells with …

Neural Coding And Decoding, Alexander Dimitrov

Systems Science Friday Noon Seminar Series

Methods based on Rate Distortion theory have been successfully used to cluster stimuli and neural responses in order to study neural codes at a level of detail supported by the amount of available data. They approximate the joint stimulus-response distribution by quantizing paired stimulus-response observations into smaller reproductions of the stimulus and response spaces. An optimal quantization is found by maximizing an information-theoretic cost function subject to both equality and inequality constraints, in hundreds to thousands of dimensions. This analytical approach has several advantages over other current approaches:

• it yields the most informative approximation of the encoding scheme given the …

Cortical Representation Of Lateralized Grasping In Chimpanzees (Pan Troglodytes): A Combined Mri And Pet Study, William D. Hopkins, Jared P. Taglialatela, Jamie L. Russell, Talia M. Nir, Jennifer Schaeffer

Faculty Articles

Functional imaging studies in humans have localized the motor-hand region to a neuroanatomical landmark call the KNOB within the precentral gyrus. It has also been reported that the KNOB is larger in the hemisphere contralateral to an individual's preferred hand, and therefore may represent the neural substrate for handedness. The KNOB has also been neuronatomically described in chimpanzees and other great apes and is similarly associated with handedness. However, whether the chimpanzee KNOB represents the hand region is unclear from the extant literature. Here, we used PET to quantify neural metabolic activity in chimpanzees when engaged in unilateral reach-and-grasping responses …

Alterations In Multiple Measures Of White Matter Integrity In Normal Women At High Risk For Alzheimer's Disease, Brian T. Gold, David K. Powell, Anders H. Andersen, Charles D. Smith

Neuroscience Faculty Publications

There is evidence that disruption of white matter (WM) microstructure is an early event in the course of Alzheimer's disease (AD). However, the neurobiological bases of WM microstructural declines in presymptomatic AD are unknown. In the present study we address this issue using a multimodal imaging approach to the study of presymptomatic AD. Participants were 37 high-risk (both family history of dementia and one or more APOE4 alleles) women and 20 low-risk (neither family history nor APOE4) women. Groups were matched for age, education, neuropsychological performance, and vascular factors that could affect white matter. Whole-brain analyses of diffusion tensor imaging …

Focusing On Optic Tectum Circuitry Through The Lens Of Genetics, Linda M. Nevin, Estuardo Robles, Herwig Baier, Ethan K. Scott

Neuroscience: Faculty Publications

The visual pathway is tasked with processing incoming signals from the retina and converting this information into adaptive behavior. Recent studies of the larval zebrafish tectum have begun to clarify how the 'micro-circuitry' of this highly organized midbrain structure filters visual input, which arrives in the superficial layers and directs motor output through efferent projections from its deep layers. The new emphasis has been on the specific function of neuronal cell types, which can now be reproducibly labeled, imaged and manipulated using genetic and optical techniques. Here, we discuss recent advances and emerging experimental approaches for studying tectal circuits as …

Alternation Rate In Perceptual Bistability Is Maximal At And Symmetric Around Equi-Dominance, Rubén Moreno-Bote, Asya Shpiro, John Rinzel, Nava Rubin

Publications and Research

When an ambiguous stimulus is viewed for a prolonged time, perception alternates between the different possible interpretations of the stimulus. The alternations seem haphazard, but closer inspection of their dynamics reveals systematic properties in many bistable phenomena. Parametric manipulations result in gradual changes in the fraction of time a given interpretation dominates perception, often over the entire possible range of zero to one. The mean dominance durations of the competing interpretations can also vary over wide ranges (from less than a second to dozens of seconds or more), but finding systematic relations in how they vary has proven difficult. Following …

Overexpression Of Amyloid Precursor Protein Induces Mitochondrial Oxidative Stress And Activates The Intrinsic Apoptosis Pathway, Matthew G. Bartley

Electronic Theses and Dissertations

Down syndrome (DS) is the most common genetic form of cognitive disability and is caused by trisomy of chromosome 21. Within chromosome 21 is the gene, amyloid precursor protein (APP). Proteolysis of APP into toxic and aggregate-prone, beta-amyloid fragments underlies the pathophysiology of Alzheimer's disease (AD). Individuals with DS develop the neuropathology that can be diagnosed as AD; however, the role of APP overexpression in this comorbidity is presently unclear. Here, we elucidated the mechanism of cell death induced by overexpression of wild type APP. Chinese hamster ovary cells transfected with a DsRed-APP fusion construct displayed caspase-3 activation and nuclear …

Neuroprotective Effects Of Anthocyanins On Neuronal Death Induced By Inhibition Of Bcl-2 And Oxidative Stress, Natalie A. Kelsey

Electronic Theses and Dissertations

Neurodegenerative diseases such as Parkinson’s and amyotrophic lateral sclerosis have devastating consequences to the afflicted patients. A major cellular pathophysiology underlying these diseases is mitochondrial oxidative stress (MOS) leading to neuronal death. Here, we investigated the neuroprotective effects of a novel class of nutraceuticals, anthocyanins, against MOS-induced death in primary cultures of rat cerebellar granule neurons (CGNs). Anthocyanins are natural antioxidants whose neuroprotective potential has yet to be examined in detail. Kuromanin and callistephin are anthocyanins derived from black rice and strawberries, respectively. Glutathione (GSH)-sensitive MOS and intrinsic apoptosis were induced in CGNs by the Bcl-2 inhibitor, HA14-1. Callistephin and …

Presenilin Is Necessary For The Function Of Cbp In The Adult Drosophila Cns, Randy S. Boyles

UNLV Theses, Dissertations, Professional Papers, and Capstones

Dominant mutations in Presenilin (Psn) have been correlated with the formation of Aß- containing plaques in patients with inherited forms of Alzheimer's disease (AD). However, a clear mechanism directly linking amyloid plaques to the pathology of familial or sporadic forms of AD has remained elusive. Thus, recent discoveries of several new substrates for Psn protease activity have sparked alternative hypotheses to explain the preclinical symptoms of AD. CBP (CREB-binding protein) is a haplo- insufficient transcriptional co-activator with histone acetyltransferase (HAT) activity that has been proposed to be a downstream target for Psn signaling. Individuals with reduced CBP levels have cognitive …

Genetic Analysis Of The Function Of The Drosophila Doublesex-Related Factor Dmrt93b, Diana O'Day

Dissertations and Theses (Open Access)

DMRT (Doublesex and Mab-3 related transcription factor) proteins generally associated with sexual differentiation in many organisms share a common DNA binding domain and are often expressed in reproductive tissues. Aside from doublesex, which is a central factor in the regulation of sex determination, Drosophila possesses three different dmrt genes that are of unknown function. Because the association with sexual differentiation and reproduction is not universal and some DMRT proteins have been found to play other developmental roles we chose to further characterize one of these Drosophila genes. We carried out genetic analysis of dmrt93B, which was previously found to be …

Direct Inputs To Off Α And G9 Ganglion Cells From Aii Amacrine Cells In Rabbit Retina, Wei-Li Liu

Dissertations and Theses (Open Access)

In the mammalian retina, AII amacrine cells are essential in the rod pathway for dark-adapted vision. But they also have a “day job”, to provide inhibitory inputs to certain OFF ganglion cells in photopic conditions. This is known as crossover inhibition. Physiological evidence from several different labs implies that AII amacrine cells provide direct input to certain OFF ganglion cells. However, previous EM analysis of the rabbit retina suggests that the dominant output of the AII amacrine cell in sublamina a goes to OFF cone bipolar cells (Strettoi et al., 1992).

Two OFF ganglion cell types in the rabbit retina, …

Neuropsychological And Emotion Processing Abnormalities In Bipolar Disorder I And Ii, Carol Randall

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bipolar disorder illness is marked by emotional lability and mood disturbance, as well as various neuropsychological deficits, and the neuroanatomical correlates of many of these deficits are beginning to be identified. Numerous studies have implicated specific cortical and sub-cortical abnormalities in areas associated with executive function, memory, motor function, and the processing of emotion. Although a large body of research has been devoted to the investigation of cognitive and emotion-processing deficits in bipolar disorder, relatively few studies have been devoted to the investigation of how these deficits differ among bipolar disorder subtypes. This is surprising in light of known symptomatological …

Pharmacological And Genetic Reversal Of Age-Dependent Cognitive Deficits Attributable To Decreased Presenilin Function, S. M.J. Mcbride, C. H. Choi, B. P. Schoenfeld, A. J. Bell, D. A. Liebelt, D. Ferreiro, R. J. Choi, P. Hinchey, M. Kollaros, A. M. Terlizzi, N. J. Ferrick, E. Koenigsberg, R. L. Rudominer, A. Sumida, S. Chiorean, Kathleen King Siwicki, H. T. Nguyen, M. E. Fortini, T. V. Mcdonald, T. A. Jongens

Biology Faculty Works

Alzheimer's disease (AD) is the leading cause of cognitive loss and neurodegeneration in the developed world. Although its genetic and environmental causes are not generally known, familial forms of the disease (FAD) are attributable to mutations in a single copy of the Presenilin (PS) and amyloid precursor protein genes. The dominant inheritance pattern of FAD indicates that it may be attributable to gain or change of function mutations. Studies of FAD-linked forms of presenilin (psn) in model organisms, however, indicate that they are loss of function, leading to the possibility that a reduction in PS activity might contribute to FAD …

Acute Responses To Estradiol Replacement In The Olfactory System Of Apoe-Deficient And Wild-Type Mice, Britto Nathan, Michael Tonsor, Robert Struble

Faculty Research & Creative Activity

Epidemiological studies suggest that estrogen therapy protects against clinical expression of chronic neurological diseases. These beneficial effects of estrogen therapy are highly modified by apolipoprotein E (apoE) through an unknown mechanism. We examined the short-term effects of estradiol replacement in ovariectomized mice on apoE expression and markers for cell proliferation, reactive gliosis, neuronal maturation, and synaptogenesis in the primary olfactory pathway of wild-type (WT) and apoE knockout (KO) mice. Three days of estradiol replacement increased apoE expression in the olfactory nerve and in the glomerular layer. Estradiol treatment also increased cell proliferation, total cell numbers, number of mature neurons in …