Medical Sciences Commons^™

The Electrophysiological And Neuropsychological Organization Of Long Term Memory, Richard J. Addante

Psychology Faculty Publications

The electrophysiological correlates of recognition memory retrieval were examined in order to identify the neural conditions that precede accurate memory retrieval, characterize the processes that contribute to high and low confidence memory responses, and determine which memory processes are impaired after brain injury. Human electroencephalogram (EEG) was recorded during recognition confidence and source memory judgments in three experiments. In Experiment 1, mid-frontal pre-stimulus theta oscillations were found to precede the stimulus presentation of items that were successfully recollected, but they were not found to be predictive of item familiarity. Moreover, during stimulus presentation, recollection was associated with an increase in …

The Vascular Link Between Intrauterine Hypoxia And Postnatal Cardiovascular Pathology, Jennifer A. Thompson

Electronic Thesis and Dissertation Repository

The effect of intrauterine hypoxia on arterial development was evaluated with use of large and small animal models. Analyses included expression and deposition of extracellular matrix (ECM) proteins, differentiation and proliferation of vascular smooth muscle cells (VSMCs), intima formation and wall thickening. A comprehensive investigation of possible molecular, mechanical and hormonal mediators of altered arterial development was afforded by a sheep model with both acute and chronic hypoxemia studies, whereas a guinea pig model allowed for long-term study. Our findings show that chronically hypoxic fetal sheep and intrauterine growth restricted (IUGR) guinea pigs exhibit a reduction in elastic fibre content …

Aging And Sympathetic Neurotransmission In Two Strains Of Rats That Differ In Longevity And Immune Profiles, Sam David Perez

Loma Linda University Electronic Theses, Dissertations & Projects

Age-related changes in sympathetic neurotransmission in immune organs may be associated with immunosenescence; however no causal relationship has been established. From previous studies in Fischer rats (F344), we have found that during middle age, sympathetic nerve activity (SNA) rises in the spleen followed by a decline in noradrenergic (NA) innervation. Also, increased sympathetic signaling via betaadrenergic receptor (β-AR) and reduced proliferation of lymphocytes are evident with increasing age. Although SNA progressively rises with age, effects of age on sympathetic factors may be different across rat strains. If causal relationships exist between sympathetic activity and immune function, they may be related …

Representation Of Somatosensory Afferents In The Cortical Autonomic Network, Ruma Goswami

Electronic Thesis and Dissertation Repository

The relationship between somatosensory stimulation and the autonomic nervous system has been established with effects on heart rate (HR) and sympathetic tone. However, the involvement of the cortical autonomic network (CAN) during muscle sensory afferent stimulation has not been identified. The main objective of the research in this dissertation was to determine the representation of somatosensory afferents in the CAN and their physiologic impact on cardiovascular control. Somatosensory afferent activation was elicited by electrical stimulation of type I and II afferents (sub-motor threshold) and type III and IV afferents (motor threshold), and CAN patterns were assessed using blood-oxygenation level-dependent functional …

The Effects Of Low Protein During Gestation On Mouse Pancreas Development And Beta Cell Regeneration, Aaron R. Cox

Electronic Thesis and Dissertation Repository

Effects of a low protein (LP) diet during gestation on the metabolism of rat offspring have been well characterized and leads to glucose intolerance in adulthood. It is unknown how LP impacts endocrine pancreas development in the mouse, or whether this affects future β-cell plasticity. Streptozotocin (STZ) – induced β-cell injury has been demonstrated to be followed by β-cell regeneration in young animals, but the mechanism(s) of regeneration are not clear. Our objective was to characterize a mouse model of maternal LP, in addition to identifying factors that contribute to the long term development of glucose intolerance and the mechanism …

Mechanisms Of Atrial Arrhythmia: Investigations Of The Neuro-Myogenic Interface In The Mouse, Jari Michael Tuomi

Electronic Thesis and Dissertation Repository

Arrhythmia mechanisms rely on multiple factors including structural (myogenic), nervous (neurogenic), and interrelated (the neuro-myogenic interface) factors. I hypothesized that due to this neuro-myogenic interface, the intrinsic cardiac autonomic nervous system (ICANS) is involved in most atrial arrhythmias. This thesis also provides a "Threshold Model" as a tool to assess the role of different physiological factors influencing arrhythmia. This model allows relative comparison and interpretation of the role of various factors influencing arrhythmogenesis. The mouse allows relatively simple manipulation of genes to determine their role in arrhythmia. This thesis determined what atrial arrhythmias are inducible in the mouse (in vivo) …

The Effect Of Training On Motoneuron Survival In Amyotrophic Lateral Sclerosis: Which Motoneuron Type Is Saved?, Sherif M. Elbasiouny, Jenna E. Schuster

Neuroscience, Cell Biology & Physiology Faculty Publications

Amyotrophic lateral sclerosis (ALS) is characterized by selective and progressive degeneration of motoneurons (MNs). Although the etiology of the disease is unknown, glutamate toxicity and reactive oxygen species toxicity have been strongly implicated in ALS pathophysiology, Training exercise has been proposed to provide a beneficial therapy during the early or late stages of ALS; however, some studies showed deleterious effects of exercise on survival in ALS.

Activation Of The Basolateral Membrane Cl- Conductance Essential For Electrogenic K+ Secretion Suppresses Electrogenic Cl- Secretion, Quanhua He, Susan T. Halm, Jin Zhang, Dan R. Halm

Neuroscience, Cell Biology & Physiology Faculty Publications

Adrenaline activates transient Cl^--secretion and sustained K⁺-secretion across isolated distal colonic mucosa of guinea pig. The Ca⁺⁺-activated Cl^- channel inhibitor CaCCinh-A01 [30μM] significantly reduced electrogenic K⁺-secretion, detected as short-circuit current (I_sc). This inhibition supported the cell model for K⁺-secretion in which basolateral membrane Cl^- channels provide an exit pathway for Cl^- entering the cell via Na⁺/K⁺/2Cl^--cotransporters. CaCCinh-A01 inhibited both I_sc and transepithelial conductance in a concentration dependent manner, IC₅₀ = 6.3 μM. GlyH-101, another Cl^- channel …

Children's Emotional State And False Memory In The Drm Paradigm, Pamela Cornejo

McNair Poster Presentations

Children are called to give testimony for highly emotional during court cases. Research indicates that children in a negative emotional state recall with lesser vividness (Berliner et al. 2003) and are more likely to incorporate false information (Levine, Burgess & Laney, 2008). The present study will examine this further by examining the influence of negative and positive emotional states on recall and recognition in child-normed lists within the Deese-Roediger-McDermott (DRM) paradigm. The DRM paradigm is a cognitive task that relies on gist memory for remembrance of the critical lure in semantically associated word lists. It is expected that the eight …

Perinatal Or Adult Nf1 Inactivation Using Tamoxifen-Inducible Plpcre Each Cause Neurofibroma Formation, Debra A. Mayes, Tilat A. Rizvi, Jose A. Cancelas, Nathan T. Kolasinski, Georgianne M. Ciraolo, Anat O. Stemmer-Rachamimov, Nancy Ratner

Neuroscience, Cell Biology & Physiology Faculty Publications

OBJECTIVES

Neurofibromas are tumors initiated by biallelic mutation of the NF1 tumor suppressor gene in the Schwann cell lineage. One idea within the field suggests that Nf1loss must occur within progenitor cells present within a critical window during Schwann cell development in order for neurofibromas to form. To test this hypothesis and to examine whethermyelinating Schwann cells can serve as aneurofibroma cell of origin, Nf1 loss was induced at perinatal or adult timepoints using a tamoxifen-inducible Plp-CreERT driver.

RESULTS

Perinatal loss of Nf1 resulted in small neurofibromas late in life, while adult loss caused large neurofibromas and morbidity beginning …

How Loss Of Neurofibromin In Oligodendrocytes Affects The Brain, Debra A. Mayes, Tilat A. Rizvi, Nathan T. Kolasinski, S. Miller, Nancy Ratner

Neuroscience, Cell Biology & Physiology Faculty Publications

Neurofibromatosis type 1 patients are predisposed to central nervous system (CNS) phenotypes including enlarged brains, delayed acquisition of motor skills, brain tumors, and cognitive deficits. Imaging and pathologic analysis suggest that changes in white matter myelination may underlie both the enlargement of white matter tracts that contributes to megancephaly, and/or hyper-intense signals visualized on MRI. To study the role(s) of Nf1 and HRasin oligodendrocytes, we examined the optic nerve and corpus callosum,myelinated fiber tracts.We studiedNf1heterozygous mice,tamoxifen-induced Nf1 loss in mature oligodendrocytes (Plp-CreERT), and a new transgenic model in which the CNPase promoter drives expression of HRasG12V. Activated HRas and loss …

Development Of Fetal Movement Between 26 And 36 Weeks’ Gestation In Response To Vibroacoustic Stimulation, Marybeth Grant-Beuttler, Laura M. Glynn, Amy L. Salisbury, Elyssia Poggi Davis, Carol Holliday, Curt A. Sandman

Psychology Faculty Articles and Research

BACKGROUND: Ultrasound observation of fetal movement has documented general trends in motor development and fetal age when motor response to stimulation is observed. Evaluation of fetal movement quality, in addition to specific motor activity, may improve documentation of motor development and highlight specific motor responses to stimulation.

AIM: The aim of this investigation was to assess fetal movement at 26 and 36-weeks gestation during three conditions (baseline, immediate response to vibro-acoustic stimulation (VAS), and post-response).

DESIGN: A prospective, longitudinal design was utilized.

SUBJECTS: Twelve normally developing fetuses, eight females and four males, were examined with continuous ultrasound imaging.

OUTCOME MEASURES: …