Neurosciences Commons^™

Serotonergic System And Gait: Dorsal Raphe Nucleus As A Control System For Gait, Nahal Farhani

Electronic Thesis and Dissertation Repository

In advanced stages of Parkinson Disease (PD), gait and postural abnormalities emerge. These symptoms are not prominent at early stages of PD despite significant dopaminergic neuronal loss. Gait abnormalities are largely not responsive to levodopa. Therefore, other types of neurons might be responsible for gait abnormalities of the PD.

Since the reticulospinal tract (RET) is mainly implicated in the control of axial muscles, the degeneration of this pathway or populations of neurons controlling this pathway might be responsible for axial symptoms. However, there is limited data about the neurons controlling the RET. Our aim in this study is to delineate …

Relationships Between Age And White Matter Integrity In Children With Phenylketonuria, Erika M. Wesonga

Arts & Sciences Electronic Theses and Dissertations

Objective: Phenylketonuria (PKU) is a hereditary metabolic disorder associated with cognitive compromise. Diffusion tensor imaging (DTI) has allowed detection of poorer microstructural white matter integrity in children with PKU, with decreased mean diffusivity (MD) in comparison with healthy children. However, very little research has been conducted to examine the trajectory of white matter development in this population. The present study investigated potential differences in the developmental trajectory of MD between children with early- and continuously-treated PKU and healthy children across a range of brain regions.

Methods: Children with PKU (n = 31, mean age = 12.2 years) were …

Behavioral Outputs Of Fragile-X Autistic Mice Exposed To Open-Field, Randomized, Short-Term Visual Stimuli, Nicholas M. Dicola, Alexander A. Chubykin

The Summer Undergraduate Research Fellowship (SURF) Symposium

Animal models of different neurological disorders are required for studying the pathophysiology of these diseases, and for potential development of pharmacological and behavioral treatments. The scientific community often uses mouse models for behavior studies due to their powerful genetic tools and low cost. However, subjective measurement techniques are often used when analyzing mice for behavioral traits which often results in discrepancies in results. An automated tracking software would aim to eliminate these discrepancies and subjective analysis. This lab has developed a software program which offered an ability to automatically collect open-field behavioral data with simultaneous on-line analysis. Python, an open …

The Effect Of Sleep On Perceptual Learning And Memory Consolidation, Vanessa Claire Irsik

UNLV Theses, Dissertations, Professional Papers, and Capstones

An ability to segregate speech accurately is essential given that most auditory environments contain other overlapping conversations or environmental noise. While perceiving speech among background noise can be difficult in and of itself, those with hearing impairments can experience considerable difficulty. While training has been shown to benefit perceptual segregation of trained sounds, it is unclear how such training transfers to sounds not included in a training regimen. The current study aimed to address this question by training listeners on a portion of sounds during a vowel segregation task, and subsequently testing on both the trained sounds and untrained sounds. …

Contribution Of The Dorsolateral Prefrontal Cortex To Attentional And Mnemonic Processes In Visual Search, Brandon Belbeck

Electronic Thesis and Dissertation Repository

A key characteristic of selective visual attention is that it may be deployed on the basis of our knowledge or goals of the task at hand. Here, we used cryogenic deactivation to investigate the contribution of the dorsolateral PFC to cognitive flexibility and working memory, as well as their relation to the deployment of attention. Macaque monkeys performed visual search tasks requiring them to foveate a target in an array of stimuli. These included a feature search, a constant-target conjunction search, a variable-target search and variable-target with delay search task, with each being more cognitively demanding than the last. Bilateral …

Minding The Aging Brain: Are We Ready For Personalized Medicine?, Jason Karlawish, Robert C. Green

Robert A. Green

No abstract provided.

Estrodial Effects On Age-Related Shifts In Learning And Memory: A Multiple Memory Systems Approach, Luis Castelan

Honors Capstone Projects - All

Many findings from our lab and others suggest that circulating estrogens as well as estrogen replacement after ovariectomy influence cognitive performance. Young female rats trained during proestrus, when estrogens are high, or with acute estradiol (E2) administration after ovariectomy perform better on the hippocampus-sensitive place task but worse on the striatum-sensitive response task (Korol et al., 2004; Korol and Kolo, 2002). Behavioral neuroscience studies tend to use male rodent models to avoid the complexities of the female reproductive cycle, producing a gap in our knowledge about neural mechanisms of learning and memory in females. As a consequence, age-related effects of …

Functional Capacity In Schizophrenia: Relationship Among Effort, Reinforcement Learning And Self-Beliefs, Sally J. Vogel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Individuals with schizophrenia exhibit a wide range of complex neurocognitive, psychiatric and behavioral impairments. Recent research suggests that this complex array of symptoms can be at least partially accounted for by dysfunction in more basic mechanisms, such as the ability to learn from positive and negative reinforcement, or the ability to exert adequate effort when completing simple tasks. Evidence also suggests that deficits in these basic mechanisms may contribute to more complex symptoms, such as functional impairment. Also, the relationship between neurocognitive deficits and functional impairment has been found to be mediated by defeatist performance beliefs. However, studies have not …

A Comparison Of The Effects Of Different Doses Of Gabab Receptor Ligands On Spatial Learning And Memory And Memory Flexibility, Chelcie Heaney

UNLV Theses, Dissertations, Professional Papers, and Capstones

The principal inhibitory neurotransmitter in the brain, gamma amino-butyric acid (GABA), mediates several types of learning and memory. Of the two main receptor subtypes for GABA, the in vivo role of GABAB receptor in learning and memory is less well characterized and the current data often conflict. Based on the current literature, it is unclear, for instance, whether enhancing GABAergic activity via the GABAB receptor could be beneficial for or detrimental to learning and memory. Hippocampally-dependent learning and memory tasks are of particular interest due to their clinical relevance to patients with schizophrenia or Alzheimer’s disease, who exhibit impaired performance …

Brain Blast 2015 Speakers Poster, Annie Leslie

Brain Blast

Poster from UNE's Brain Blast 2015 listing the expected presenters at this event.*

Enhanced Cgmp-Dependent Signaling In Astrocytes: Novel Therapeutic Target In Alzheimer's Disease, Nyema M. Woart

PCOM Biomedical Studies Student Scholarship

Over five million Americans suffer from Alzheimer’s Disease (AD), with an expected 34% increase in the incidence in this disease over the next decade. Unfortunately, there is no cure for AD. Recent studies have indicated that drugs which increase the levels of cyclic guanosine-3’5’-monophosphate (cGMP) may help preserve learning and memory in AD and enhance cognition in the aging brain; however, the mechanism(s) of how cGMP exerts this beneficial effect is unknown. The present findings now suggest that elevation of cGMP in astrocytes depresses inhibitory potassium currents in these cells to stimulate their protective influence on neuronal activity. Cellular currents …

Targeting Methylglyoxal And Ppar Gamma To Alleviate Neuropathic Pain Associated With Type 2 Diabetes, Ryan B. Griggs

Theses and Dissertations--Physiology

Neuropathic pain affects up to 50% of the 29 million diabetic patients in the United States. Neuropathic pain in diabetes manifests as a disease of the peripheral and central nervous systems. The prevalence of type 2 diabetes is far greater than type 1 (90%), yet the overwhelming focus on type 1 models this has left the mechanisms of pain in type 2 diabetes largely unknown. Therefore I aimed to improve the current mechanistic understanding of pain associated with type 2 diabetes using two preclinical rodent models: Zucker Diabetic Fatty rats and db/db mice. In addition, I highlight the translational importance …

Influence Of Planning Resources On Gait Control In Parkinson’S Disease, Frederico P. Faria

Theses and Dissertations (Comprehensive)

Movement disturbances in individuals with Parkinson’s disease (PD) have been associated with difficulties to plan complex actions. Performance of simple and complex actions overloads resources for individuals with Parkinson’s disease (PD). However, it is unclear if central resources required to plan gait adjustments while walking exacerbate gait disturbances of patients with PD. More specifically, it is unclear how gait impairments, sensory processing, and the dopaminergic system influence the load on processing resources (e.g. cognitive load) during the planning of step modifications. In order to investigate the relative influence of these factors on cognitive load and its impact on gait control, …