Neurosciences Commons^™

Expanding The Basic Science Debate: The Role Of Physics Knowledge In Interpreting Clinical Findings., Mark Goldszmidt, John Paul Minda, Sarah L Devantier, Aimee L Skye, Nicole N Woods

Brain and Mind Institute Researchers' Publications

Current research suggests a role for biomedical knowledge in learning and retaining concepts related to medical diagnosis. However, learning may be influenced by other, non-biomedical knowledge. We explored this idea using an experimental design and examined the effects of causal knowledge on the learning, retention, and interpretation of medical information. Participants studied a handout about several respiratory disorders and how to interpret respiratory exam findings. The control group received the information in standard "textbook" format and the experimental group was presented with the same information as well as a causal explanation about how sound travels through lungs in both the …

Frequency-Dependent Conduction Block In Demyelinating Focal Neuropathies, Brad V. Watson

Electronic Thesis and Dissertation Repository

It is the objective of this thesis to demonstrate conduction block across regions of focal demyelination by utilizing a conventional electrophysiological technique used frequently in the diagnosis of peripheral nerve disease. Specifically, patients with moderate to severe carpal tunnel syndrome (CTS), but, with no evidence of conduction block via conventional motor nerve conduction study techniques, were assessed in the initial studies of this thesis for evidence of frequency-dependent conduction block (FDB) by way of high-frequency nerve stimulation (HFNS) applied across the region of entrapment. The final studies examined whether FDB could be demonstrated along the median motor fibers in mild …

Gradients And Ranges Of Visually Selective Attention Based On Location, Objects, Color, And Size: Gradients Are Universal, But Range Is Uniquely Spatial, William S. Bush

Open Access Dissertations

Two interesting properties of the distribution of spatially selective attention have been noted in the behavioral and electrophysiological literature. First, there is a graded field of attention that expands from the center of the attended area. Second, the size of the attended area can be adjusted to be either larger or smaller in order to match the demands of the current task. Five event-related potential (ERP) studies are presented that extend these findings in several important ways; 1) The time frame of these two distribution properties is different. Results are consistent with a two stage model of spatial attention in …

Exosome-Mediated Shuttling Of Microrna-29 Regulates Hiv Tat And Morphine-Mediated Neuronal Dysfunction., Guoku Hu, H Yao, A D. Chaudhuri, Sowmya V. Yelamanchili, H Wen, P D. Cheney, Howard S. Fox, Shilpa J. Buch

Journal Articles: Pharmacology & Experimental Neuroscience

Neuronal damage is a hallmark feature of HIV-associated neurological disorders (HANDs). Opiate drug abuse accelerates the incidence and progression of HAND; however, the mechanisms underlying the potentiation of neuropathogenesis by these drugs remain elusive. Opiates such as morphine have been shown to enhance HIV transactivation protein Tat-mediated toxicity in both human neurons and neuroblastoma cells. In the present study, we demonstrate reduced expression of the tropic factor platelet-derived growth factor (PDGF)-B with a concomitant increase in miR-29b in the basal ganglia region of the brains of morphine-dependent simian immunodeficiency virus (SIV)-infected macaques compared with the SIV-infected controls. In vitro relevance …

Psychophysical And Neural Evidence For Emotion-Enhanced Perceptual Vividness, Rebecca M. Todd, Deborah Talmi, Taylor W. Schmitz, Josh Susskind, Adam K. Anderson

Brain and Mind Institute Researchers' Publications

Highly emotional events are associated with vivid "flashbulb" memories. Here we examine whether the flashbulb metaphor characterizes a previously unknown emotion-enhanced vividness (EEV) during initial perceptual experience. Using a magnitude estimation procedure, human observers estimated the relative magnitude of visual noise overlaid on scenes. After controlling for computational metrics of objective visual salience, emotional salience was associated with decreased noise, or heightened perceptual vividness, demonstrating EEV, which predicted later memory vividness. Event-related potentials revealed a posterior P2 component at ~200 ms that was associated with both increased emotional salience and decreased objective noise levels, consistent with EEV. Blood oxygenation level-dependent …

Perceptual Fluency Can Be Used As A Cue For Categorization Decisions., Sarah J Miles, John Paul Minda

Brain and Mind Institute Researchers' Publications

Learning in the prototype distortion task is thought to involve perceptual learning in which category members experience an enhanced visual response (Ashby & Maddox. Annual Review of Psychology, 56, 149-178, 2005). This response likely leads to more-efficient processing, which in turn may result in a feeling of perceptual fluency for category members. We examined the perceptual-fluency hypothesis by manipulating fluency independently from category membership. We predicted that when perceptual fluency was induced using subliminal priming, this fluency would be misattributed to category membership and would affect categorization decisions. In a prototype distortion task, the participants were more likely to judge …

Gonadotropin-Releasing Hormone Plasticity: A Comparative Perspective., T J Stevenson, T P Hahn, S A Macdougall-Shackleton, G F Ball

Brain and Mind Institute Researchers' Publications

Gonadotropin-releasing hormone 1 (GnRH1) is a key regulator of the reproductive neuroendocrine system in vertebrates. Recent developments have suggested that GnRH1 neurons exhibit far greater plasticity at the cellular and molecular levels than previously thought. Furthermore, there is growing evidence that sub-populations of GnRH1 neurons in the preoptic area are highly responsive to specific environmental and hormonal conditions. In this paper we discuss findings that reveal large variation in GnRH1 mRNA and protein expression that are regulated by social cues, photoperiod, and hormonal feedback. We draw upon studies using histochemistry and immediate early genes (e.g., c-FOS/ZENK) to illustrate that specific …

Interactions Among Positions In The Third And Fourth Membrane-Associated Domains At The Intersubunit Interface Of The N-Methyl-D-Aspartate Receptor Forming Sites Of Alcohol Action, Hong Ren, Yulin Zhao, Donard S. Dwyer, Robert W. Peoples

Biomedical Sciences Faculty Research and Publications

The N-methyl-d-aspartate (NMDA) glutamate receptor is a major target of ethanol in the brain. Previous studies have identified positions in the third and fourth membrane-associated (M) domains of the NMDA receptor GluN1 and GluN2A subunits that influence alcohol sensitivity. The predicted structure of the NMDA receptor, based on that of the related GluA2 subunit, indicates a close apposition of the alcohol-sensitive positions in M3 and M4 between the two subunit types. We tested the hypothesis that these positions interact to regulate receptor kinetics and ethanol sensitivity by using dual substitution mutants. In single-substitution mutants, we found that a position …

Frequency-Specificity And Pattern-Specificity Of The Buildup Of Auditory Stream Segregation, David Michael Weintraub

UNLV Theses, Dissertations, Professional Papers, and Capstones

During repeating sequences of low (A) and high (B) tones in an "...ABAB..." pattern, the likelihood of hearing two separate streams ("streaming") increases with more repetitions of the patterns, a phenomenon referred to as "buildup". Previous studies have shown that buildup is frequency specific (Anstis & Saida, 1985) and that its biasing effects decays over several seconds (Beauvois & Meddis, 1997). No study has examined whether the frequency specificity of buildup persists for such a long duration. To address these issues, Experiment 1 tested the decay of frequency-specific and non-frequency specific buildup. The results revealed that (1) frequency-specific buildup effects …

Differential Effects Of Macaque Dorsolateral Prefrontal Deactivations During Uncued And Cued Role Conditions, Sabeeha Hussein

Electronic Thesis and Dissertation Repository

Cognitive control enables us to guide our behaviour in an appropriate, context-dependent manner. This behavioral flexibility is probed by task-switching paradigms, which require working memory to maintain relevant rules and flexibility to switch between rules. The dorsolateral prefrontal cortex (DLPFC) has been implicated in rule maintenance by neuroimaging and electrophysiological studies. While these studies have identified a correlation between DLPFC activity and rule maintenance, deactivation studies allow us to establish a causal relationship. Here we have examined the effect of bilateral deactivation of areas 46 and 9/46d on rule maintenance, while a monkey (Macacca mulatta) performed blocks of …

The Role Of Amino-Terminal In Determining Transjunctional Voltage-Dependent Gating And Unitary Conductance Of Cx36 And Cx50 Gap Junction Channels, Li Xin

Electronic Thesis and Dissertation Repository

Gap junction (GJ) channels directly connect the cytoplasm of neighboring cells, and allow for the transfer of ions and small molecules between two cells. GJ channels are known to be gated by the transjunctional voltage (V_j, the voltage difference between the interiors of adjoining cells), which is referred to as V_j-dependent gating. GJ channels show varying degrees of sensitivity to V_j, depending on the type of connexin(s) comprising the GJ channel. GJ channels formed by different connexins also show unique unitary conductance ranging from ~ 10 pS to ~300 pS. However, the molecular structures …

Calclium-Calmodulin Regulation Of Trpm2 Currents, Brian M. W. Lockhart

Electronic Thesis and Dissertation Repository

TRPM2 (1507 amino acids), a non-selective cation channel with substantial permeability for Ca²⁺, is responsive to oxidative stress, and is a mediator of cell death in several cell types. Ca²⁺-calmodulin has been shown to promote channel activation and inactivation, however the mechanisms are not fully understood. Identifying candidate CaM binding sites using in silico screening, I hypothesized that Ca²⁺-dependent inactivation (CDI) of TRPM2 is mediated by an intracellular CaM binding domain unique from that of activation (406-415AA). I systematically determined the minimum binding domains for three CaM candidate sites on TRPM2’s intracellular domains using …

Purines And Neuronal Excitability: Links To The Ketogenic Diet [Post-Print], Susan A. Masino, Masahito Kawamura Jr., David N. Ruskin, J D. Geiger, D. Boison

Faculty Scholarship

ATP and adenosine are purines that play dual roles in cell metabolism and neuronal signaling. Acting at the A(1) receptor (A(1)R) subtype, adenosine acts directly on neurons to inhibit excitability and is a powerful endogenous neuroprotective and anticonvulsant molecule. Previous research showed an increase in ATP and other cell energy parameters when an animal is administered a ketogenic diet, an established metabolic therapy to reduce epileptic seizures, but the relationship among purines, neuronal excitability and the ketogenic diet was unclear. Recent work in vivo and in vitro tested the specific hypothesis that adenosine acting at A(1)Rs is a key mechanism …

Exploring Picture Word Priming Effects In Healthy Aging Adults Using Event Related Potentials, Sasha C. Christopher

USF Tampa Graduate Theses and Dissertations

Objective: The aim of the present study was to investigate the mechanics with which older adults activate and access different subdomains of their mental lexicons during word retrieval for picture naming.

Method: Data were analyzed for 12 aging, native English speakers who performed a picture-word priming task. The auditory probe words were presented in the following conditions in relation to the picture stimuli: Identically related, strongly semantically related, weakly semantically related, strongly phonologically related, weakly phonologically related, semantically related to the strong phonological relative of the target picture label, or phonologically-related to the strong semantic relative of the target picture …

Visualizing Spatiotemporal Dynamics Of Apoptosis After G1 Arrest By Human T Cell Leukemia Virus Type 1 Tax And Insights Into Gene Expression Changes Using Microarray-Based Gene Expression Analysis., Mariluz Araínga, Hironobu Murakami, Yoko Aida

Journal Articles: Pharmacology & Experimental Neuroscience

BACKGROUND: Human T cell leukemia virus type 1 (HTLV-1) Tax is a potent activator of viral and cellular gene expression that interacts with a number of cellular proteins. Many reports show that Tax is capable of regulating cell cycle progression and apoptosis both positively and negatively. However, it still remains to understand why the Tax oncoprotein induces cell cycle arrest and apoptosis, or whether Tax-induced apoptosis is dependent upon its ability to induce G1 arrest. The present study used time-lapse imaging to explore the spatiotemporal patterns of cell cycle dynamics in Tax-expressing HeLa cells containing the fluorescent ubiquitination-based cell cycle …

Antioxidant Rescue Of Nf1/Ras-Induced Myelin And Vasculature Dysfunction, Debra A. Mayes, Tilat A. Rizvi, Shyra J. Miller, Rachel Oberst, Anat Stemmer-Rachamimov, Nancy Ratner

Neuroscience, Cell Biology & Physiology Faculty Publications

No abstract provided.

Unique Features And Neuronal Properties In A Multisensory Cortex, W. Alex Foxworthy

Theses and Dissertations

UNIQUE FEAUTRES OF ORGANIZATION AND NEURONAL PROPERTIES IN A MULTISENSORY CORTEX Multisensory processing is a ubiquitous sensory effect that underlies a wide variety of behaviors, such as detection and orientation, as well as perceptual phenomena from speech comprehension to binding. Such multisensory perceptual effects are presumed to be based in cortex, especially within areas known to contain multisensory neurons. However, unlike their lower-level/primary sensory cortical counterparts, little is known about the connectional, functional and laminar organization of higher-level multisensory cortex. Therefore, to examine the fundamental features of neuronal processing and organization in the multisensory cortical area of the posterior parietal …

Toward A Working Theory Of Neurorhetorics, Jeffrey L. Honnold

USF Tampa Graduate Theses and Dissertations

This piece makes the claim that rhetoric is first philosophy--before philosophy, epistemology, ontology, or any other field--or that rhetoric is, at the least, on equal footing as these fields because:

empathy--and thusly the impulse for communication--is physiologically hardwired into humans; special distinctions between human and animal are largely artificial constructions, as is evidenced by neurosciences; "hard" science, in the form of neurosciences, is providing entrance points & opportunities for rhetoric to raise its status within the academy; and said neurosciences, in addition to empathy studies, have shown strong evidence supporting linguistic and evolutionary links between humans and other species, thereby …

Resting-State Connectivity Identifies Distinct Functional Networks In Macaque Cingulate Cortex., R Matthew Hutchison, Thilo Womelsdorf, Joseph S Gati, L Stan Leung, Ravi S Menon, Stefan Everling

Brain and Mind Institute Researchers' Publications

Subregions of the cingulate cortex represent prominent intersections in the structural networks of the primate brain. The relevance of the cingulate to the structure and dynamics of large-scale networks ultimately requires a link to functional connectivity. Here, we map fine-grained functional connectivity across the complete extent of the macaque (Macaca fascicularis) cingulate cortex and delineate subdivisions pertaining to distinct identifiable networks. In particular, we identified 4 primary networks representing the functional spectrum of the cingulate: somatomotor, attention-orienting, executive, and limbic. The cingulate nodes of these networks originated from separable subfields along the rostral-to-caudal axis and were characterized by positive and …

Frecuencia De Leptospira Spp En Porcinos De Crianza Tecnificada Y De Traspatio Beneficiados En Dos Mataderos De Lima, Luis Anampa V., Hermelinda Rivera G., Nestor Falcon P., Mariluz Araínga, Mercy Ramirez V.

Journal Articles: Pharmacology & Experimental Neuroscience

The objective of this study was to determine the frequency of antibodies against Leptospira spp in pigs reared in five well-managed farms (n = 163) and from 11 backyard breeding (n = 133) owners in the valley Lima, Peru. Blood samples (n=296) were collected in two slaughterhouses for antibody detection against eight serovars of Leptospira by microaglutination test. The 85.8 ± 3.9% (254/296) of samples had antibodies against one or more serovars of Leptospira. . The 89.6 ± 4.7% (146/163) and 82.1 ± 6.5% (108/133) of samples from well-managed farms and from backyard breeding pigs showed antibodies against Leptospira spp. …