Neurosciences Commons^™

Fear Learning And The Olfactory Bulb: Neural Correlates Of Behavioral Fear Generalization, Jordan Marie Ross

Theses and Dissertations (ETD)

The exploration of how learning alters neural coding to guide behaviors remains fundamental to neuroscience. At the most basic level, the ability for organisms to flexibly adapt to changing environments and situations is paramount to biological success and often manifests in behavioral responses controlled by neural activity. For example, organisms must modify their behavior to defensive responses in the face of biological threat. Neural circuitry is involved in coordinating an initial defensive behavioral response but must undergo reorganization in order to reliably employ defensive responses in subsequent encounters based on a cue that signals imminent danger. One such form of …

Reduced Gabaergic Signaling At The Axon Initial Segment Decreases Vigilance State Transitioning, Austin John Boren

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sleep is a highly regulated homeostatic process that is disrupted in an estimated 50-70 million Americans. Regulation of sleep depends upon coordinated signaling of multiple neurotransmitter systems. In particular, inhibitory gamma-aminobutyric acid (GABA) signaling is required to suppress wake-active brain regions in order to initiate and maintain sleep states. GABA type A receptors (GABAARs) are ionotropic receptors with subunit compositions uniquely enriched on subcellular domains of target cells. α2 subunit-containing GABAARs are the primary target of GABA released onto the axon initial segment (AIS), a site critical for phasing the oscillatory activity of cortical cells. α2-containing GABAARs have previously been …

Developmental Neurobiology Neu 201, Joanna Burkhardt

Library Impact Statements

No abstract provided.

Neuroscience Professional Development Neu 230, Joanna Burkhardt

Library Impact Statements

No abstract provided.

Short Amylin Receptor Antagonist Peptides Improve Memory Deficits In Alzheimer’S Disease Mouse Model, Rania Soudy, Ryoichi Kimura, Aarti Patel, Wen Fu, Kamaljit Kaur, David Westaway, Jing Yang, Jack Jhamandas

Pharmacy Faculty Articles and Research

Recent evidence supports involvement of amylin and the amylin receptor in the pathogenesis of Alzheimer’s disease (AD). We have previously shown that amylin receptor antagonist, AC253, improves spatial memory in AD mouse models. Herein, we generated and screened a peptide library and identified two short sequence amylin peptides (12–14 aa) that are proteolytically stable, brain penetrant when administered intraperitoneally, neuroprotective against Aβ toxicity and restore diminished levels of hippocampal long term potentiation in AD mice. Systemic administration of the peptides for five weeks in aged 5XFAD mice improved spatial memory, reduced amyloid plaque burden, and neuroinflammation. The common residue SQELHRLQTY …

Anti-N-Methyl-D-Aspartate Receptor Encephalitis., Gregory Tanquary, William Fraser, Kaitlin M Bowers

Neuroscience Articles

Anti-N-methyl-D-aspartate receptor (NMDA) encephalitis is an underrecognized encephalitis that may be mistaken for a wide variety of mental illnesses and causes of delirium. This syndrome is predominantly present in young females presenting with acute psychotic episodes, autonomic instability, and neurologic abnormalities. It is commonly associated with ovarian teratoma. Our case illustrates anti-NMDA encephalitis presenting in a young female with progressive mental status changes and neurologic abnormalities throughout her emergency department course. We review the investigative approach, diagnostic modalities, and treatment options in patient management. This case emphasizes the need for a high index of suspicion of anti-NMDA receptor encephalitis when …

Cortical Beta Oscillations Are Associated With Motor Performance Following Visuomotor Learning, Svenja Espenhahn, Bernadette C.M. Van Wijk, Holly E. Rossiter, Archy O. De Berker, Nell D. Redman, Jane Rondina, Joern Diedrichsen, Nick S. Ward

Brain and Mind Institute Researchers' Publications

© 2019 The Authors People vary in their capacity to learn and retain new motor skills. Although the relationship between neuronal oscillations in the beta frequency range (15–30 Hz) and motor behaviour is well established, the electrophysiological mechanisms underlying individual differences in motor learning are incompletely understood. Here, we investigated the degree to which measures of resting and movement-related beta power from sensorimotor cortex account for inter-individual differences in motor learning behaviour in the young and elderly. Twenty young (18–30 years) and twenty elderly (62–77 years) healthy adults were trained on a novel wrist flexion/extension tracking task and subsequently retested …

Self-Directed Down-Regulation Of Auditory Cortex Activity Mediated By Real-Time Fmri Neurofeedback Augments Attentional Processes, Resting Cerebral Perfusion, And Auditory Activation, Matthew Sherwood, Jason G. Parker, Emily E. Diller, Subhashini Ganapathy, Kevin B. Bennett, Carlos R. Esquivel, Jeremy T. Nelson

Neuroscience, Cell Biology & Physiology Faculty Publications

In this work, we investigated the use of real-time functional magnetic resonance imaging (fMRI) with neurofeedback training (NFT) to teach volitional down-regulation of the auditory cortex (AC) using directed attention strategies as there is a growing interest in the application of fMRI-NFT to treat neurologic disorders. Healthy participants were separated into two groups: the experimental group received real feedback regarding activity in the AC; the control group was supplied sham feedback yoked from a random participant in the experimental group and matched for fMRI-NFT experience. Each participant underwent five fMRI-NFT sessions. Each session contained 2 neurofeedback runs where participants completed …

Glucocorticoids And “Stress” Are Not Synonymous, Scott Macdougall-Shackleton

Brain and Mind Institute Researchers' Publications

Synopsis

Reference to glucocorticoids as “stress hormones” has been growing in prevalence in the literature, including in comparative and environmental endocrinology. Although glucocorticoids are elevated in response to a variety of stressors in vertebrate animals, the primary functions of glucocorticoids are not responding to stressors and they are only one component of complex suite of physiological and behavioral responses to stressors. Thus, the use of the short-hand phrase “stress hormone” can be misleading. Further, simply measuring glucocorticoids is not equivalent to measuring a stress response, nor is manipulating glucocorticoids equivalent to exposing an animal to a stressor. In this commentary …

Mapping Reward Values To Cues, Locations, And Objects: The Influence Of Reward Associations On Visual Attention, Constanza De Dios

USF Tampa Graduate Theses and Dissertations

Previous work has attempted to fit reward-driven attentional selection as being exogenous (stimulus-driven) or endogenous (goal-driven). However, recent work suggests that reward’s effects on attention depend on the type of stimulus feature that the motivational information is imparted during learning (incentive salience). If true, then reward should not be limited to solely impacting early perceptual or late categorization processes attention. The current study used event-related potentials (ERPs) to test the idea that reward’s effects on attention depend on the process that the reward information is embedded – early perceptual or late categorization. Results demonstrated reward-driven effects on perceptual representation when …

An Eye Opener In Stroke: Mitochondrial Dysfunction And Stem Cell Repair In Stroke-Induced Retinal Ischemia, Hung Vu Thien Nguyen

USF Tampa Graduate Theses and Dissertations

Stoke is a leading cause of disability and mortality across the globe, making it a global health crisis. However, treatments for stroke remain limited with narrow therapeutic time window. Visual impairment negatively affects patients’ quality of life. During stroke, the disruption in blood flow might affect both brain and eye resulting in cerebral and retinal ischemia. Currently, there is a lack of treatment option that targets both cerebral and retinal ischemia. Ischemic stroke pathology is complex and multiphasic. The ischemic event is followed by a secondary cascade of inflammatory cytokines exacerbating the initial focal injury and expanding into the penumbra. …

Circuit-Specific Control Of The Medial Entorhinal Inputs To The Dentate Gyrus By Atypical Presynaptic Nmdars Activated By Astrocytes, Iaroslav Savtchouk, Maria Amalia Di Castro, Rugina Ali, Hiltrud Stubbe, Rafael Lujan, Andrea Volterra

Biomedical Sciences Faculty Research and Publications

Here, we investigated the properties of presynaptic N-methyl-D-aspartate receptors (pre-NMDARs) at corticohippocampal excitatory connections between perforant path (PP) afferents and dentate granule cells (GCs), a circuit involved in memory encoding and centrally affected in Alzheimer’s disease and temporal lobe epilepsy. These receptors were previously reported to increase PP release probability in response to gliotransmitters released from astrocytes. Their activation occurred even under conditions of elevated Mg²⁺ and lack of action potential firing in the axons, although how this could be accomplished was unclear. We now report that these pre-NMDARs contain the GluN3a subunit conferring them low Mg^{2+ …}

Understanding The Neural Bases Of Implicit And Statistical Learning, Laura J. Batterink, Ken A. Paller, Paul J. Reber

Brain and Mind Institute Researchers' Publications

© 2019 Cognitive Science Society, Inc. Both implicit learning and statistical learning focus on the ability of learners to pick up on patterns in the environment. It has been suggested that these two lines of research may be combined into a single construct of “implicit statistical learning.” However, by comparing the neural processes that give rise to implicit versus statistical learning, we may determine the extent to which these two learning paradigms do indeed describe the same core mechanisms. In this review, we describe current knowledge about neural mechanisms underlying both implicit learning and statistical learning, highlighting converging findings between …

Macaque Anterior Cingulate Cortex Deactivation Impairs Performance And Alters Lateral Prefrontal Oscillatory Activities In A Rule-Switching Task, Liya Ma, Jason L. Chan, Kevin Johnston, Stephen G. Lomber, Stefan Everling

Brain and Mind Institute Researchers' Publications

© 2019 Ma et al. In primates, both the dorsal anterior cingulate cortex (dACC) and the dorsolateral prefrontal cortex (dlPFC) are key regions of the frontoparietal cognitive control network. To study the role of the dACC and its communication with the dlPFC in cognitive control, we recorded local field potentials (LFPs) from the dlPFC before and during the reversible deactivation of the dACC, in macaque monkeys engaging in uncued switches between 2 stimulus-response rules, namely prosaccade and antisaccade. Cryogenic dACC deactivation impaired response accuracy during maintenance of—but not the initial switching to—the cognitively demanding antisaccade rule, which coincided with a …

Enhancing Cell Seeding And Osteogenesis Of Mscs On 3d Printed Scaffolds Through Injectable Bmp2 Immobilized Ecm-Mimetic Gel, Farahnaz Fahimipour, Erfan Dashtimoghadam, Mohammad Mahdi Hasani-Sadrabadi, Jessica Vargas, Daryoosh Vashaee, Doug Lobner, Tahereh S. Jafarzadeh Kashi, Behnam Ghasemzadeh, Lobat Tayebi

Biomedical Sciences Faculty Research and Publications

Objective

Design of bioactive scaffolds with osteogenic capacity is a central challenge in cell-based patient-specific bone tissue engineering. Efficient and spatially uniform seeding of (stem) cells onto such constructs is vital to attain functional tissues. Herein we developed heparin functionalized collagen gels supported by 3D printed bioceramic scaffolds, as bone extracellular matrix (ECM)-mimetic matrices. These matrices were designed to enhance cell seeding efficiency of mesenchymal stem cells (MSCs) as well as improve their osteogenic differentiation through immobilized bone morphogenic protein 2 (BMP2) to be used for personalized bone regeneration.

Methods

A 3D gel based on heparin-conjugated collagen matrix capable of …

Mouse Performance On A Novel Touchscreen Continuous Performance Task Is Dependent On Signaling In The Prelimbic Cortex, Tyler D. Dexter, Daniel Palmer, Amy C. Reichelt, Anita Taksokhan, Lisa M. Saksida, Tim J. Bussey

Western Research Forum

Attention is the cognitive processing that facilitates the ability to target and attend to relevant environmental stimuli, while filtering out irrelevant or distracting stimuli. Control over selective attention is theorized to be dependent on organized neural communication that stems from the medial prefrontal cortex (mPFC). To evaluate selective and sustained attention, mice were trained on the novel touchscreen rodent continuous performance task (rCPT), a task designed to emulate the human CPT. In the rodent version, images are continuously presented on a touchscreen, where mice have been trained to selectively respond to one image type while suppressing responses to all others. …

Competitive Frontoparietal Interactions Mediate Implicit Inferences, Martijn E. Wokke, Tony Ro

Publications and Research

Frequent experience with regularities in our environment allows us to use predictive information to guide our decision process. However, contingencies in our environment are not always explicitly present and sometimes need to be inferred. Heretofore, it remained unknown how predictive information guides decision-making when explicit knowledge is absent and how the brain shapes such implicit inferences. In the present experiment, 17 human participants (9 females) performed a discrimination task in which a target stimulus was preceded by a predictive cue. Critically, participants had no explicit knowledge that some of the cues signaled an upcoming target, allowing us to investigate how …

Exercise To Combat Neurocognitive Decline In Older Adults, Joyla Furlano

Western Research Forum

Background: Older adults with type 2 diabetes (T2D) experience cognitive decline and neural atrophy, and therefore are at high risk for developing dementia. Consequently, older adults at-risk for developing T2D (i.e., overweight or pre-diabetic individuals) are at higher risk for cognitive decline, and intervening at this point may prevent or delay the onset of such decline. One promising lifestyle intervention that may improve neurocognitive function is exercise. For example, 6 months of aerobic training improves cognitive function in overweight or pre-diabetic older adults, but research has not examined whether resistance training (RT) can produce comparable results in this population.

Hypothesis: …

The Use Of High-Dose Cervical Spinal Cord Stimulation In The Treatment Of Chronic Upper Extremity And Neck Pain., Trey A Baird, Chris S Karas

Neuroscience Articles

BACKGROUND: Dorsal column spinal cord stimulation is used for the treatment of chronic neuropathic pain of the axial spine and extremities. Recently, high-dose (HD) thoracic dorsal column stimulation for paresthesias has been successful. This study evaluates the utility of HD stimulation in the cervical spine for managing upper neck and upper extremity pain and paresthesias.

METHODS: Three patients suffering from cervical and upper extremity chronic pain were assessed. Each underwent a two-stage process that included a trial period, followed by permanent stimulator implantation. Therapy included the latest HD stimulation settings including a pulse width of 90 μs, a frequency setting …

An Integration-To-Bound Model Of Decision-Making That Accounts For The Spectral Properties Of Neural Data, Ramón Guevara Erra, Marco Arbotto, Aaron Schurger

Psychology Faculty Articles and Research

Integration-to-bound models are among the most widely used models of perceptual decision-making due to their simplicity and power in accounting for behavioral and neurophysiological data. They involve temporal integration over an input signal (“evidence”) plus Gaussian white noise. However, brain data shows that noise in the brain is long-term correlated, with a spectral density of the form 1/fα (with typically 1 < α < 2), also known as pink noise or ‘1/f’ noise. Surprisingly, the adequacy of the spectral properties of drift-diffusion models to electrophysiological data has received little attention in the literature. Here we propose a model of accumulation of evidence for decision-making that takes into consideration the spectral properties of brain signals. We develop a generalization of the leaky stochastic accumulator model using a Langevin equation whose non-linear noise term allows for varying levels of autocorrelation in the time course of the decision variable. We derive this equation directly from magnetoencephalographic data recorded while subjects performed a spontaneous movement initiation task. We then propose a nonlinear model of accumulation of evidence that accounts for the ‘1/f’ spectral properties of brain signals, and the observed variability in the power spectral properties of brain signals. Furthermore, our model outperforms the standard drift-diffusion model at approximating the empirical waiting time distribution.

Ephb-Ephrinb Cis Interaction Regulates Filopodial Movement, Yu-Ting Mao, Matthew B. Dalva

Department of Neuroscience Posters

Neural connections are initiated by motile dendritic and axonal protrusions, such as dendritic filopodia and axonal growth cones. Dendritic filopodia interview many axons and then choose the correct ones to make stable contacts. Specific rates of EphB activation in dendritic filopodia controls the decision of filopodia to reject or stabilize a synaptic contact onto an axon. However, it remains unknown how EphB activity in dendritic filopodia is modulated to regulate filopodial decisions. Here using an optogenetic approach, we find that photoactivation of a cis-interaction between EphB2 and ephrinB3 prevents filopodial retraction, likely driving filopodial stabilization. Using photoactivatable EphB2KD as a …

The Neural Association Between Arithmetic And Basic Numerical Processing Depends On Arithmetic Problem Size And Not Chronological Age, Anna A. Matejko, Daniel Ansari

Brain and Mind Institute Researchers' Publications

© 2019 The Authors The intraparietal sulcus (IPS) is thought to be an important region for basic number processing (e.g. symbol-quantity associations) and arithmetic (e.g. addition). Evidence for shared circuitry within the IPS is largely based on comparisons across studies, and little research has investigated number processing and arithmetic in the same individuals. It is also unclear how the neural overlap between number processing and arithmetic is influenced by age and arithmetic problem difficulty. This study investigated these unresolved questions by examining basic number processing (symbol-quantity matching) and arithmetic (addition) networks in 26 adults and 42 children. Number processing and …

Resonate: Reflections And Recommendations On Implicit Biases Within The Ismrm, Esther A.H. Warnert, Krishna Nayak, Ravi Menon, Curt Rice, John Port, Elizabeth A. Morris, Daniel K. Sodickson, Pia Sundgren, Karla L. Miller, Udunna C. Anazodo

Brain and Mind Institute Researchers' Publications

No abstract provided.

Positions In The N‐Methyl‐D‐Aspartate Receptor Glun2c Subunit M3 And M4 Domains Regulate Alcohol Sensitivity And Receptor Kinetics, Man Wu, Priya Katti, Yulin Zhao, Robert W. Peoples

Biomedical Sciences Faculty Research and Publications

Background

Alcohol alters synaptic transmission in the brain. The N‐methyl‐D‐aspartate (NMDA) receptor (NMDAR), a subtype of glutamate‐gated ion channel, is an important synaptic target of alcohol in the brain. We and others have previously identified 4 alcohol‐sensitive positions in the third and fourth membrane‐associated (M) domains, designated M3_1‐2and M4_1‐2, of the GluN1, GluN2A, and GluN2B NMDAR subunits. In the present study, we tested whether the corresponding positions in the GluN2C subunit also regulate alcohol sensitivity and ion channel gating.

Methods

We performed alanine‐ and tryptophan‐scanning mutagenesis in the GluN2C subunit followed by expression in HEK …

Limbic-Predominant Age-Related Tdp-43 Encephalopathy (Late): Consensus Working Group Report, Peter T. Nelson, Dennis W. Dickson, John Q. Trojanowski, Clifford R. Jack, Patricia A. Boyle, Konstantinos Arfanakis, Rosa Rademakers, Irina Alafuzoff, Johannes Attems, Carol Brayne, Ian T. S. Coyle-Gilchrist, Helena C. Chui, David W. Fardo, Margaret E. Flanagan, Glenda Halliday, Suvi R. K. Hokkanen, Sally Hunter, Gregory A. Jicha, Yuriko Katsumata, Claudia H. Kawas, C. Dirk Keene, Gabor G. Kovacs, Walter A. Kukull, Allan I. Levey, Nazanin Makkinejad, Thomas J. Montine, Shigeo Murayama, Melissa E. Murray, Sukriti Nag, Robert A. Rissman, William W. Seeley, Reisa A. Sperling, Charles L. White Iii, Lei Yu, Julie A. Schneider

Sanders-Brown Center on Aging Faculty Publications

We describe a recently recognized disease entity, limbic-predominant age-related TDP-43 encephalopathy (LATE). LATE neuropathological change (LATE-NC) is defined by a stereotypical TDP-43 proteinopathy in older adults, with or without coexisting hippocampal sclerosis pathology. LATE-NC is a common TDP-43 proteinopathy, associated with an amnestic dementia syndrome that mimicked Alzheimer’s-type dementia in retrospective autopsy studies. LATE is distinguished from frontotemporal lobar degeneration with TDP-43 pathology based on its epidemiology (LATE generally affects older subjects), and relatively restricted neuroanatomical distribution of TDP-43 proteinopathy. In community-based autopsy cohorts, ∼25% of brains had sufficient burden of LATE-NC to be associated with discernible cognitive impairment. Many …

A Multimodal Approach To Investigate Brain Reorganization After Spinal Cord Injury Using Functional Magnetic Resonance Imaging And Functional Near-Infrared Spectroscopy, Keerthana Deepti Karunakaran

Dissertations

Traumatic Spinal Cord Injury (SCI) results in structural and functional neurological changes at both the brain and the level of the spinal cord. Anatomical studies indicate decreased grey matter volume in sensorimotor and non-sensorimotor regions of the cortex following SCI; whereas, neurophysiological findings mostly report altered functional activity in the sensorimotor nodes of the cortex, subcortex, and cerebellum. Therefore, it is currently unknown whether tissue atrophy observed in non-motor related areas has any concomitant functional consequences. Furthermore, the neural underpinnings of adaptive neuroplasticity after SCI is not well-defined in the current literature. Hence, this dissertation is a pioneer study investigating …

High-Performance Learning Systems Using Low-Precision Nanoscale Devices, Nandakumar Sasidharan Rajalekshmi

Dissertations

Brain-inspired computation promises a paradigm shift in information processing, both in terms of its parallel processing architecture and the ability to learn to tackle problems deemed unsolvable by traditional algorithmic approaches. The computational capability of the human brain is believed to stem from an interconnected network of 100 billion compute nodes (neurons) that interact with each other through approximately 10¹⁵ adjustable memory junctions (synapses). The conductance of synapses is modifiable allowing the network to learn and perform various cognitive functions. Artificial neural networks inspired by this architecture have demonstrated even super-human performance in many complex tasks.

Computational systems based …

Temporal And Functional Cortical Aspects Related To Mirror Visual Feedback During Target-Directed Movement In Healthy And Stroke Individuals, Maryam Rohafza

Dissertations

Stroke is the leading cause of disability in the United States (American Heart Association, American Stroke Association) affecting 800,000 individuals annually (i.e., one person every 45 seconds). Therapy for stroke often uses repetitive task practice, which is difficult to perform for patients due to impairment. Mirror visual feedback (MVF) based rehabilitation uses the effect of observing the mirror reflection of volitional movement of one limb, to activate visuomotor brain areas that process movement of the opposite limb. In persons with hemiplegia due to stroke, exercising the less affected limb while observing its reflection, perceived by them as the motion of …

Neuroscience Journal Club Neu 460, Joanna Burkhardt

Library Impact Statements

No abstract provided.

The Inflammatory Response After Ischemic Stroke: Targeting Β2 And Β1 Integrins, Danielle N. Edwards, Gregory J. Bix

Sanders-Brown Center on Aging Faculty Publications

Ischemic stroke is a leading cause of death and disability with limited therapeutic options. Resulting inflammatory mechanisms after reperfusion (removal of the thrombus) result in cytokine activation, calcium influx, and leukocytic infiltration to the area of ischemia. In particular, leukocytes migrate toward areas of inflammation by use of integrins, particularly integrins β₁ and β₂. Integrins have been shown to be necessary for leukocyte adhesion and migration, and thus are of immediate interest in many inflammatory diseases, including ischemic stroke. In this review, we identify the main integrins involved in leukocytic migration following stroke (α_Lβ_{2 …}