Neuroscience and Neurobiology Commons^™

Rescuing Age-Related Proteolysis Deficits With Methylene Blue, Shane E. Pullins

Theses and Dissertations

The average lifespan is constantly increasing with the advent of new medical techniques, and age-related cognitive decline is becoming a prevalent societal issue. Even during healthy aging, humans and rats exhibit progressive deficits in episodic/declarative memory. In laboratory rats, age-related memory impairment can be assessed with trace fear conditioning (TFC). Recent research implicates ubiquitin proteasome system-mediated protein degradation in the synaptic plasticity supporting memory formation and retrieval. In rats, aging leads to decreased basal proteolytic activity in brain structures known to support the acquisition and retrieval of trace fear memories, and our preliminary data suggests activity-dependent proteasome activity declines in …

The Role Of Hippocampal And Medial Prefrontal Interactions In The Estrogenic Regulation Of Memory, Jennifer Tuscher

Theses and Dissertations

Dendritic spine plasticity is thought to be essential for the formation and storage of memories. The sex-steroid hormone 17-estradiol (E2) increases dendritic spine density in 2 brain regions necessary for memory formation, the dorsal hippocampus (DH) and medial prefrontal cortex (mPFC), but the mechanisms through which it does so remain largely unknown. Further, the extent to which these brain regions interact to mediate E2’s effects on memory is also unclear. Recently, we found that infusion of E2 directly into the DH also increases dendritic spine density in the DH and mPFC, and that these effects depend upon rapid activation of …

Sex Differences In Differential Fear Conditioning During The Acquisition And Consolidation Of Learned Safety, David Sylvan Reis

Theses and Dissertations

The ability to distinguish between threatening and non-threatening situations requires careful regulation of behavioral and physiological responses to stress and fear. Deficits in fear regulation are maladaptive and can lead to the development of anxiety disorders such as PTSD. Women are nearly twice as likely to develop PTSD as are men and laboratory animal studies have shown facilitated fear acquisition, resistance to fear extinction, deficits in extinction retention and impaired discrimination between danger and safety cues in females. Taken together this suggests a propensity for reduced inhibitory control over fear responding in females. Here we investigate the mechanisms underlying fear …

Development Of Mechanosensory Innervation In The Frog, Xenopus Laevis, Peter Andrew Feuk

Theses and Dissertations

ABSTRACT

DEVELOPMENT OF MECHANOSENSORY INNERVATION IN THE FROG, XENOPUS LAEVIS

by

Peter Feuk

The University of Wisconsin-Milwaukee, 2017

Under the Supervision of Dr. R. David Heathcote

This study aims to investigate whether a specific target cell in the epidermis of the African clawed frog, Xenopus laevis, guides the initial outgrowth and pattern of Rohon-Beard (RB) cells and their survival. RB cells are primary mechanosensory neurons present during the early developmental stages of X. laevis. These neurons provide sensory input to the frog throughout embryonic and larval development before initiating apoptosis around the start of metamorphosis. The innervation of embryonic skin …

Visually-Guided Reaching Under Varying Cognitive And Motor Demand In Young Adult Females With A History Of Concussions, Christopher James Fueger

Theses and Dissertations

Every day, vision guides one’s actions to help one successfully navigate through a complex environment. When our visual and motor systems interact efficiently, we may not fully appreciate how flawless and beneficial this process can be to our daily functioning. Yet, one’s available neural resources needed to successfully perform visually-guided movements do have limits. When an individual suffers a brain injury, such as a concussion, the available resources may be compromised. Examining the extent of this decreased resource pool requires challenging the cognitive abilities enough to observe a behavioral deficit. The purpose of this study was to examine the long-term …

Investigating The Functional Connectivity Of The Bed Nucleus Of The Stria Terminalis During Conditions Of Threat And Safety Using High Resolution 7 Tesla Fmri, Walker Scott Pedersen

Theses and Dissertations

An influential model of the extended amygdala defines fear as the immediate response to phasic threat and anxiety as the prolonged response to unpredictable or sustained threat (Davis, Walker, Miles & Grillon, 2010). This model proposes that in response to unpredictable threat, the centromedial amygdala (CeA) activates the bed nucleus of the stria terminalis (BNST), which coordinates the anxiety response, and, in turn, inhibits the CeA. Connectivity between the BNST and both the basolateral amygdala (BLA) and hippocampus may also play an important role in the coordination of the anxiety response (Davis et al., 2010; Herman et al., 2003; Zhu, …

Electrophysiological And Morphological Characterization Of Neurons In The Granular Retrosplenial Cortex, Andrew Nicholas Nye

Theses and Dissertations

The retrosplenial cortex (RSC) is a centrally located brain region that has reciprocal connections with several brain regions important for memory, including the prefrontal cortex, para-hippocampal region, hippocampal formation, and rhinal cortices. The RSC is also well connected with structures important for sensory processing, including the parietal cortex, thalamus, and visual cortices. Due to this connectivity, and early evidence that suggests the RSC plays a critical role in learning and memory, the region has recently gained much more research attention. Early studies found that patients with brain damage that includes the RSC have difficulty with verbal and visual information, retrieving …