Other Neuroscience and Neurobiology Commons^™

The Role Of Napping On Memory Consolidation In Preschool Children, Laura Kurdziel

Doctoral Dissertations

Nocturnal sleep has been shown to benefit memory in adults and children. During the preschool age range (~3-5 years), the distribution of sleep across the 24-hour period changes dramatically. Children transition from biphasic sleep patterns (a nap in addition to overnight sleep) to a monophasic sleep pattern (only overnight sleep). In addition, early childhood is a time of neuronal plasticity and pronounced acquisition of new information. This dissertation sought to examine the relationship between daytime napping and memory consolidation in preschool-aged children during this transitional time. Children were taught either a declarative or an emotional task in the morning, and …

Increased Body Weight In Adulthood Following A Peripubertal Stressor And Proposed Mechanism For Effects Of Increased Adiposity On Estrogen-Dependent Behaviors, Christina F. Gagliardi

Masters Theses

Exposure to certain stressors during a sensitive period around puberty can lead to enduring effects on an animal’s response to estradiol. In estradiol-influenced behaviors, such as sexual receptivity, hippocampal-dependent learning and memory, depression-like behavior, and anxiety-like behaviors, exposure to a peripubertal stressor such as shipping stress or an injection of lipopolysaccharide (LPS) can eliminate or even reverse the normal response to estradiol. In addition to regulating these behaviors, estradiol play a role in the regulation of body weight. While some of the previous studies touched on short-term effects on body weight, no systemic long-term study of the effects of a …

Advances In Image Acquisition And Filtering For Mri Neuroimaging At 7 Tesla, Andrew T. Curtis

Electronic Thesis and Dissertation Repository

Performing magnetic resonance imaging at high magnetic field strength promises many improvements over low fields that are of direct benefit in functional neuroimaging. This includes the possibility of improved signal-to-noise levels, and increased BOLD functional contrast and spatial specificity. However, human MRI at 7T and above suffers from unique engineering challenges that limit the achievable gains. In this thesis, three technological developments are introduced, all of which address separate issues associated with functional magnetic resonance neuroimaging at very high magnetic field strengths.

First, the image homogeneity problem is addressed by investigating methods of RF shimming — modifying the excitation portion …

Activity-Dependent Serotonergic Excitation Of Callosal Projection Neurons In The Mouse Prefrontal Cortex, Emily K. Stephens, Daniel Avesar, Allan T. Gulledge

Dartmouth Scholarship

Layer 5 pyramidal neurons (L5PNs) in the mouse prefrontal cortex respond to serotonin (5-HT) according to their long-distance axonal projections; 5-HT_1A (1A) receptors mediate inhibitory responses in corticopontine (CPn) L5PNs, while 5-HT_2A (2A) receptors can enhance action potential (AP) output in callosal/commissural (COM) L5PNs, either directly (in “COM-excited” neurons), or following brief 1A-mediated inhibition (in “COM-biphasic” neurons). Here we compare the impact of 5-HT on the excitability of CPn and COM L5PNs experiencing variable excitatory drive produced by current injection (DC current or simulated synaptic current) or with exogenous glutamate. 5-HT delivered at resting membrane potentials, or paired …

Investigating The Multiple Hit Hypothesis Of Parkinson Disease Using Transgenic Lrrk2-R1441g Rats, Komal T. Shaikh

Electronic Thesis and Dissertation Repository

The ‘multiple hit’ hypothesis of Parkinson disease (PD) suggests that the combination of several risk factors leads to the development of PD. Here, we explore the interaction between two potential causes of PD; a genetic mutation in the leucine-rich repeat kinase 2 (LRRK2) gene and exposure to the neurotoxin, Paraquat. This project characterizes transgenic BAC rats expressing human LRRK2 bearing the familial PD mutation, R1441G. These rats were tested for PD-related deficits at 3, 6, 9 & 12 months. These rats were then exposed to intraperitoneal injections of Paraquat. We hypothesized that LRRK2^R1441G rats will show increased vulnerability …

Mechanisms Of Astrocyte Contribution To Bortezomib-Induced Peripheral Neuropathy, Caleb R. Robinson

Dissertations & Theses (Open Access)

Bortezomib is a proteasome inhibitor used in the treatment of multiple myeloma and other non-solid malignancies, alone or in combination with other chemotherapy drugs. Like other chemotherapeutic agents, bortezomib treatment is frequently accompanied by chemotherapy-induced peripheral neuropathy (CIPN) that may be dose-limiting, adversely affecting quality of life and prognosis. The mechanisms behind bortezomib-induced peripheral neuropathy (BIPN) and CIPN overall are largely unknown. Recent findings in other pain models have indicated substantial involvement of glial cells in chronic pain. Although injury models have shown activation of both astrocytes and microglia following insult, research in other CIPN models has shown astrocytic activation …

Discovery And Elucidation Of The Fgfr3-Tacc3 Recurrent Fusion In Glioblastoma, Brittany C. Parker Kerrigan

Dissertations & Theses (Open Access)

Fusion genes occur due to chromosomal instability where two previously separate genes rearrange and fuse together, forming a hybrid gene. The first fusions were reported in leukemias; however, with the advent of more powerful sequencing technologies, fusions have recently been reported in several solid tumors. Using next-generation deep sequencing approaches, we discovered a fusion gene connecting the fibroblast growth factor receptor 3 (FGFR3) gene to the transforming coiled-coil containing protein 3 (TACC3) gene in glioblastoma multiforme. The fusion occurred in 8.3% of patient samples, but not in low grade or normal samples. FGFR3-TACC3 produced an in-frame …

Statistical Summaries In Action: Evidence From The Antisaccade Task, Caitlin Gillen

Electronic Thesis and Dissertation Repository

Antisaccades require the top-down process of decoupling a stimulus and a response and executing a saccade mirror-symmetrical to a target. Notably, research has yet to characterize the endpoint properties of antisaccades. Experiment One had participants antisaccade in two trial blocks that contained the same number of target eccentricities but differed in respect to their magnitudes. Experiment Two manipulated the frequency that individual target eccentricities were presented within a block of trials. Notably, Experiments One and Two were designed to determine whether the top-down control of antisaccades renders the processing of target features via a strategy of perceptual averaging. Results showed …

Inter- And Intralimb Adaptations To A Sensory Perturbation During Activation Of The Serotonin System After A Low Spinal Cord Transection In Neonatal Rats, Misty M. Strain, Sierra D. Kauer, Tina Kao, Michele R. Brumley

Publications and Research

Activation of the serotonin system has been shown to induce locomotor activity following a spinal cord transection. This study examines how the isolated spinal cord adapts to a sensory perturbation during activation of the serotonergic system. Real-time and persistent effects of a perturbation were examined in intact and spinal transected newborn rats. Rats received a spinal surgery (sham or low thoracic transection) on postnatal day 1 and were tested 9 days later. At test, subjects were treated with the serotonergic receptor agonist quipazine (3.0 mg/kg) to induce stepping behavior. Half of the subjects experienced range of motion (ROM) restriction during …

Proliferation, Migration, And Survival Of Cells In The Telencephalon Of The Ball Python, Python Regius, Thomas B. Bales

Master's Theses

Reptiles exhibit neurogenesis throughout the brain during adulthood. However, very few studies have quantified telencephalon-wide neurogenesis in adulthood, and no studies have performed these investigations in snakes. Quantifying neurogenesis in the adult snake is essential to understanding class-wide adult neurogenesis and providing insight into the evolution of this trait. The thymidine analog 5-bromo-2’-deoxyuridine (BrdU) was used to quantify cell proliferation, migration, and survival in the ball python (Python regius). First, to determine the proper dose of BrdU for injection we subcutaneously injected 50mg/kg, 100mg/kg, and 250mg/kg into 15 adult male P. regius. We found the 250mg/kg dose …

Fty720 (Fingolimod) Provides Insight Into The Molecular Mechanisms Of Multiple Sclerosis, Madelyn Elizabeth Crawford

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Multiple sclerosis (MS) is a neurodegenerative disorder caused by a prolonged immune- mediated inflammatory response that targets myelin. Nearly all of the drugs approved for the treatment of MS are general immunosuppressants or only function in symptom management. The oral medication fingolimod, however, is reported to have direct therapeutic effects on cells of the central nervous system in addition to immunomodulatory functions. Fingolimod is known to interact with sphingosine-1-phosphate (S1P) receptors, and the most widely- accepted theory for its mechanism of action is functional antagonism of the receptor. This review examines significant neuromodulatory effects achieved by functional antagonism of the …

Astroglial Boundary Formation And Epha4 Signaling In Neuroblast Migration, Nicholas B. Gallo

University Scholar Projects

Adult neurogenesis, the process of generating new neurons from neural precursors, is a highly complex process that is limited to two specific areas of the brain, the dentate gyrus of the hippocampus and the subventricular zone (SVZ). Despite continued research investigating neurogenesis in these two regions, we still lack a fundamental understanding of the molecular mechanisms of neural cell division, migration, differentiation, and integration in the postnatal brain. In particular, the rostral migratory stream (RMS), which is a cellular migratory route for newly generated neuronal precursors that travel from the SVZ to the olfactory bulb, will provide a useful model …

Astroglial Boundary Formation And Epha4 Signaling In Neuroblast Migration, Nicholas B. Gallo

Honors Scholar Theses

Adult neurogenesis, the process of generating new neurons from neural precursors, is a highly complex process that is limited to two specific areas of the brain, the dentate gyrus of the hippocampus and the subventricular zone (SVZ). Despite continued research investigating neurogenesis in these two regions, we still lack a fundamental understanding of the molecular mechanisms of neural cell division, migration, differentiation, and integration in the postnatal brain. In particular, the rostral migratory stream (RMS), which is a cellular migratory route for newly generated neuronal precursors that travel from the SVZ to the olfactory bulb, will provide a useful model …

Dendrites Of Cardiac Ganglion Regulate Heartbeat Of American Lobster, Homarus Americanus, Through Stretch Feedback, Mara R. Chin-Purcell

Honors Projects

Central pattern generators are neuronal networks that produce reliable rhythmic motor output. A simple pattern generator, known as the cardiac ganglion (CG), controls the heart of the American lobster, Homarus americanus. Previous studies have suggested that stretch feedback relays information to the cardiac ganglion about the degree of filling in the heart, and that this feedback is mediated by stretch-sensitive dendrites extending from CG neurons. I sought to determine the mechanisms behind this stretch feedback pathway. One hundred second extension pyramids were applied to each heart while amplitude and frequency of contractions were recorded; 87% of hearts responded to …

Effects Of Resting State On Perceptual Learning, Sarah Eagleman Ph.D.

Dissertations & Theses (Open Access)

Psychophysical experiments in humans have demonstrated that improvements in perceptual learning tasks occur following daytime rests. The neural correlates of how rest influences subsequent sensory processing during these tasks remain unclear. One possible neural mechanism that may underlie this behavioral improvement is reactivation. Previously evoked network activity reoccurs – reactivates - in the absence of further stimulation. Reactivation was initially discovered in the hippocampus but has now been found in several brain areas including cortex. This phenomenon has been implicated as a general mechanism by which neural networks learn and store sensory information. However, whether reactivation occurs in areas relevant …

The Effects Of Picrotoxin And Ethanol On Crayfish Escape And Central Motor Pattern Neural Circuits, Rebecca Bierman, Nathan Hardcastle, Colin Istvan

Georgia State Undergraduate Research Conference

No abstract provided.

Comparison Of Functional Network Connectivity For Passive-Listening And Active-Response Narrative Comprehension In Adolescents, Yingying Wang, Scott K. Holland

Center for Brain, Biology, and Behavior: Faculty and Staff Publications

Comprehension of narrative stories plays an important role in the development of language skills. In this study, we compared brain activity elicited by a passive-listening version and an active-response (AR) version of a narrative comprehension task by using independent component (IC) analysis on functional magnetic resonance imaging data from 21 adolescents (ages 14–18 years). Furthermore, we explored differences in functional network connectivity engaged by two versions of the task and investigated the relationship between the online response time and the strength of connectivity between each pair of ICs. Despite similar brain region involvements in auditory, temporoparietal, and frontoparietal language networks …

The Effect Of Age On Neural Processing Of Pleasant Soft Touch Stimuli, April C. May, Jennifer L. Stewart, Susan F. Tapert, Martin P. Paulus

Publications and Research

Tactile interactions with our environment stimulate afferent fibers within the skin, which deliver information about sensations of pain, texture, itch and other feelings to the brain as a comprehensive sense of self. These tactile interactions can stimulate brain regions involved in interoception and reward processing. This study examined subjective, behavioral, and neural processing as a function of age during stimulation of A-beta (Aβ) and C tactile (CT) afferents using a soft brush stroke task. 16 adolescents (ages 15–17), 22 young adults (ages 20–28), and 20 mature adults (ages 29–55) underwent a simple continuous performance task while periodically anticipating and experiencing …

Differential Effects Of Early-Life Seizures On Neuronal Inhibition In The Hippocampus Of Seizure-Prone And Seizure-Resistant Rats, Amir Abbas Mohseni Zonoozi

Electronic Thesis and Dissertation Repository

The aim of this study is to investigate the long-term physiological consequences of early-life seizures in rats of different genetic backgrounds. Rats bred to be prone (Fast) or resistant (Slow) to amygdala kindling were induced with status epilepticus (SE) on postnatal day (PND) 10 by injecting 3 mg/kg i.p. kainic acid; SE consisted of seizures for 2 h, including stage 5 seizures (lying down with four limb tonic-clonic convulsions). Littermates injected with the same volume of saline i.p. served as controls. On PND 40-55, population spikes (PSs) were recorded at the CA1 pyramidal cell layer in hippocampal slices in vitro …

The Helminthological Society Of Washington 2013 Anniversary Award: Larry S. Roberts, Sherman S. Hendrix

Center for Brain, Biology, and Behavior: Faculty and Staff Publications

Dr. Roberts was born in the great state of Texas, and much of his early life is murky, but snakes are often mentioned. Larry received his Bachelor’s degree at Southern Methodist University; his Master of Science at the University of Illinois; and his Doctorate in the Department of Pathobiology at the Johns Hopkins School of Hygiene and Public Health. Larry’s doctoral research, published in Experimental Parasitology, documented the early development and crowding effect of the tapeworm, Hymenolepis diminuta, in the rat small intestine. His publication on this subject opened the door to the golden age of cestode physiology and biochemistry …