Neuroscience and Neurobiology Commons^™

Working Memory Impairments In Chromosome 22q11.2 Deletion Syndrome: The Roles Of Anxiety And Stress Physiology, Ashley F. P. Sanders

LSU New Orleans Theses and Dissertations

Stress and anxiety negatively impact the working memory system by competing for executive resources. Broad memory deficits have been reported in individuals with chromosome 22q11.2 deletion syndrome (22q11.2DS). We investigated anxiety and physiological stress reactivity in relation to visuospatial working memory impairments in 20 children with 22q11.2DS and 32 typically developing children (M = 11.10 years, SD = 2.95). Results indicate reduced post-stress RSA recovery and overall increased levels of cortisol in children with 22q11.2DS. Additionally, anxiety mediated the relationship between 22q11.2DS and visuospatial working memory impairment. However, there was no indication that stress response physiology mediated this association. …

Diffuse Traumatic Brain Injury Induces Prolonged Immune Sysregulation And Potentiates Hyperalgesia Following A Peripheral Immune Challenge, Rachel K. Rowe, Gavin I. Ellis, Jordan L. Harrison, Adam D. Bachstetter, Gregory F. Corder, Linda J. Van Eldik, Bradley K. Taylor, Francesc Marti, Jonathan Lifshitz

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Background: Nociceptive and neuropathic pain occurs as part of the disease process after traumatic brain injury (TBI) in humans. Central and peripheral inflammation, a major secondary injury process initiated by the traumatic brain injury event, has been implicated in the potentiation of peripheral nociceptive pain. We hypothesized that the inflammatory response to diffuse traumatic brain injury potentiates persistent pain through prolonged immune dysregulation.

Results: To test this, adult, male C57BL/6 mice were subjected to midline fluid percussion brain injury or to sham procedure. One cohort of mice was analyzed for inflammation-related cytokine levels in cortical biopsies and serum along an …

Alterations In Gray Matter Volume Due To Unilateral Hearing Loss, Xingchao Wang, Pengfei Xu, Peng Li, Zhenmin Wang, Fu Zhao, Zhixian Gao, Lei Xu, Yue-Jia Luo, Jin Fan, Pinan Liu

Publications and Research

Although extensive research on neural plasticity resulting from hearing deprivation has been conducted, the direct influence of compromised audition on the auditory cortex and the potential impact of long durations of incomplete sensory stimulation on the adult cortex are still not fully understood. In this study, using voxel-based morphometry, we evaluated gray matter (GM) volume changes that may be associated with reduced hearing ability and the duration of hearing impairment in 42 unilateral hearing loss (UHL) patients with acoustic neuromas compared to 24 normal controls. We found significant GM volume increases in the somatosensory and motor systems and GM volume …

Modeling The Joint Distribution Of Scene Events At An Edge, James Elder, Ying Li

MODVIS Workshop

Edges in an image arise from discontinuities in scene variables, namely reflectance (R), illumination (I), depth (D) and surface orientation (O). Prior studies on edge classification have viewed it as a binary classification problem: each edge is assumed to arise from one of two disjoint categories (e.g., depth or not depth, shadow or not shadow). Here we suggest an alternate view in which an edge may signal discontinuities in any combination of the scene variables (RIDO). To explore this model, we had 4 trained observers label one randomly selected edge in each of 1,000 randomly selected images drawn from the …

Identifying Falsifiable Predictions Of The Divisive Normalization Model Of V1 Neurons, Tadamasa Sawada, Alexander A. Petrov

MODVIS Workshop

The divisive normalization model (DNM, Heeger, 1992) accounts successfully for a wide range of phenomena observed in single-cell physiological recordings from neurons in primary visual cortex (V1). The DNM has adjustable parameters to accommodate the diversity of V1 neurons, and is quite flexible. At the same time, in order to be falsifiable, the model must be rigid enough to rule out some possible data patterns. In this study, we discuss whether the DNM predicts any physiological result of the V1 neurons based on mathematical analysis and computational simulations. We identified some falsifiable predictions of the DNM. The main idea is …

Modelling Response Properties Across The Orientation Map In Visual Cortex, Erin M. Koch, Jianzhong Jin, Jose-Manuel Alonso, Qasim Zaidi

MODVIS Workshop

Stimulus orientation in the primary visual cortex of primates and carnivores is mapped as iso-orientation domains radiating from pinwheel centers, where orientation preferences of neighboring cells change circularly. Whether this orientation map has a function is debated, because many mammals, such as rodents, do not have such maps. Here we model our physiological results that two fundamental properties of visual cortical responses, contrast saturation and cross-orientation suppression, are stronger within iso-orientation domains than at pinwheel centers. Our model expands on a standard thalamic model of cross orientation suppression, and explains differences between orientation domains by intra-cortical excitation (not normalization) from …

Derivatives And Inverse Of A Linear-Nonlinear Multi-Layer Spatial Vision Model, Borja Galan, Marina Martinez-Garcia, Praveen Cyriac, Thomas Batard, Marcelo Bertalmio, Jesus Malo

MODVIS Workshop

Analyzing the mathematical properties of perceptually meaningful linear-nonlinear transforms is interesting because this computation is at the core of many vision models. Here we make such analysis in detail using a specific model [Malo & Simoncelli, SPIE Human Vision Electr. Imag. 2015] which is illustrative because it consists of a cascade of standard linear-nonlinear modules. The interest of the analytic results and the numerical methods involved transcend the particular model because of the ubiquity of the linear-nonlinear structure.

Here we extend [Malo&Simoncelli 15] by considering 4 layers: (1) linear spectral integration and nonlinear brightness response, (2) definition of local contrast …

Towards A Functional Explanation Of The Connectivity Lgn - V1, Marina Martinez-Garcia, Borja Galan, Luis M. Martinez, Jesus Malo

MODVIS Workshop

The principles behind the connectivity between LGN and V1 are not well understood. Models have to explain two basic experimental trends: (i) the combination of thalamic responses is local and it gives rise to a variety of oriented Gabor-like receptive felds in V1 [1], and (ii) these filters are spatially organized in orientation maps [2]. Competing explanations of orientation maps use purely geometrical arguments such as optimal wiring or packing from LGN [3-5], but they make no explicit reference to visual function. On the other hand, explanations based on func- tional arguments such as maximum information transference (infomax) [6,7] usually …

Towards A Unified Model Of Classical And Extra-Classical Receptive Fields, David A. Mély, Thomas Serre

MODVIS Workshop

One of the major goals in neuroscience is to understand how the cortex processes information. A substantial effort has thus gone into mapping classical receptive fields (cRF) across areas of the visual cortex and characterizing input-output relationships through linear-nonlinear response functions. Recently, there has been a lot of interest in mapping the extra-classical receptive field (extra-cRF) as well, by using contextual stimuli. The extra-cRF is a region outside the cRF that modulates a cell’s response but that is incapable of driving it on its own. However, existing models typically focus on one particular visual modality (form, motion, disparity or color), …

How Deep Is The Feature Analysis Underlying Rapid Visual Categorization?, Sven Eberhardt, Jonah Cader, Thomas Serre

MODVIS Workshop

Rapid categorization paradigms have a long history in experimental psychology: Characterized by short presentation times and fast behavioral responses, these tasks highlight both the speed and ease with which our visual system processes natural object categories. Previous studies have shown that feed-forward hierarchical models of the visual cortex provide a good fit to human visual decisions. At the same time, recent work has demonstrated significant gains in object recognition accuracy with increasingly deep hierarchical architectures: From AlexNet to VGG to Microsoft CNTK – the field of computer vision has championed both depth and accuracy. But it is unclear how well …

Spatial Synaptic Growth And Removal For Learning Individual Receptive Field Structures, Michael Teichmann, Fred H. Hamker

MODVIS Workshop

One challenge in creating neural models of the visual system is the appropriate definition of the connectivity. The modeler constrains the results with its definition. Unfortunately, there is often just insufficient information about connection sizes available, e.g. for deeper layer or different neuron types like interneurons. Hence, a mechanism refining the connection structure based on the learnings would be appreciated.

Such mechanism can be found in the human brain by structural plasticity. That is, the formation and removal of synapses. For our model, we exploit that synaptic connections are likely to be formed in the proximity of other synapses and …

A Geometric Approach To Sparse Coding Yields Insight Into Nonlinear Responses, Kedarnath Vilankar, James Golden, David Field

MODVIS Workshop

In artificial and biological networks, it is a common accepted practice to describe a neurons (biological or artificial) response properties by a two-dimensional feature map (receptive field). However, real neurons have nonlinear response properties which are not represented by their receptive fields. The efficient coding mechanisms such as sparse coding network or ICA, learn the response properties of V1 neurons from natural images using neural networks. These networks learn the receptive fields which are similar to the receptive fields of V1 neurons. These networks also produces some of the nonlinearities (such as end-stopping and non-classical surround effect), which are exhibited …

Using Deep Features To Predict Where People Look, Matthias Kümmerer, Matthias Bethge

MODVIS Workshop

When free-viewing scenes, the first few fixations of human observers are driven in part by bottom-up attention. We seek to characterize this process by extracting all information from images that can be used to predict fixation densities (Kuemmerer et al, PNAS, 2015). If we ignore time and observer identity, the average amount of information is slightly larger than 2 bits per image for the MIT 1003 dataset. The minimum amount of information is 0.3 bits and the maximum 5.2 bits. Before the rise of deep neural networks the best models were able to capture 1/3 of this information on average. …

Modelling Short-Latency Disparity-Vergence Eye Movements Under Dichoptic Unbalanced Stimulation, Agostino Gibaldi, Guido Maiello, Peter J. Bex, Silvio P. Sabatini

MODVIS Workshop

Vergence eye movements align the optical axes of our two eyes onto an object of interest, thus facilitating the binocular summation of the images projected onto the left and the right retinae into a single percept. Both the computational substrate and the functional behaviour of binocular vergence eye movements have been the topic of in depth investigation. Here, we attempt to bring together what is known about computation and function of vergence mechanism. To this aim, we evaluated of a biologically inspired model of horizontal and vertical vergence control, based on a network of V1 simple and complex cells. The …

Learning Object Representations For Modeling Attention In Real World Scenes, Alex Schwarz, Frederik Beuth, Fred H. Hamker

MODVIS Workshop

Models of visual attention have been rarely used in real world tasks as they have been typically developed for psychophysical setups using simple stimuli. Thus, the question remains how objects must be represented to allow such models an operation in real world scenarios. We have previously presented an attention model capable of operating on real-world scenes (Beuth, F., and Hamker, F. H. 2015, NCNC, which is a successor of Hamker, F. H., 2005, Cerebral Cortex), and show here how its object representations have been learned. We have used a learning rule based on temporal continuity (Földiák, P., 1991, Neural Computation) …

Tau And Aβ Imaging, Csf Measures, And Cognition In Alzheimer's Disease, Matthew R. Brier, Brian Gordon, Karl Friedrichsen, John E. Mccarthy, Ari Stern, Jon Christensen, Christopher Owen, Patricia Aldea, Yi Su, Jason Hassenstab, Nigel J. Cairns, David M. Holtzman, Anne M. Fagan, John C. Morris, Tammie L.S. Benzinger, Beau M. Ances

Mathematics Faculty Research

Alzheimer’s disease (AD) is characterized by two molecular pathologies: cerebral β-amyloidosis in the form of β-amyloid (Aβ) plaques and tauopathy in the form of neurofibrillary tangles, neuritic plaques, and neuropil threads. Until recently, only Aβ could be studied in humans using positron emission tomography (PET) imaging owing to a lack of tau PET imaging agents. Clinical pathological studies have linked tau pathology closely to the onset and progression of cognitive symptoms in patients with AD. We report PET imaging of tau and Aβ in a cohort of cognitively normal older adults and those with mild AD. Multivariate analyses identified unique …

Soluble Rage Treatment Delays Progression Of Amyotrophic Lateral Sclerosis In Sod1 Mice, Judyta K. Juranek, Gurdip K. Daffu, Matthew S. Geddis, Huilin Li, Rosa Rosario, Benjamin J. Kaplan, Lauren Kelly, Ann Marie Schmidt

Publications and Research

The etiology of amyotrophic lateral sclerosis (ALS), a fatal motor neuron disorder characterized by progressive muscle weakness and spasticity, remains largely unknown. Approximately 5–10% of cases are familial, and of those, 15–20% are associated with mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1). Mutations of the SOD1 gene interrupt cellular homeostasis and contribute to cellular toxicity evoked by the presence of altered SOD1, along with other toxic species, such as advanced glycation end products (AGEs). AGEs trigger activation of their chief cell surface receptor, RAGE (receptor for advanced glycation end products), and induce RAGE-dependent cellular stress and inflammation in …

Expression And Function Of Inflammation-Associated Micrornas In Traumatic Brain Injury, Emily Harrison

Theses & Dissertations

MicroRNAs (miRNAs) are important regulators of gene expression. Many neurological diseases, including traumatic brain injury alter expression of miRNAs in the brain. However, the function of these molecules in the context of TBI is largely unknown. Here we report multiple potential roles for miRNAs in TBI, some of which extend beyond the traditional model of post-transcriptional regulation, highlighting that these RNA molecules may have broader implications for the neurobiology of disease. We found that miR-155 plays an essential role in interferon expression after CCI and that miR-155 contributes to TBI induced anxiety, potentially through regulation of interferons. Expression of miR-155 …

Reverse Genetic Screening Of Innexin Gap Junction Proteins In Drosophila Neurons, Shannon P. Fox

Senior Honors Projects, 2010-2019

The reflexive response and perception of pain (nociception) is an evolutionarily conserved process in animals. Pain can be a major health concern and current treatments often prove insufficient, especially in regards to chronic pain. Greater understanding of the molecular processes underlying pain sensation could lead to new and more effective treatments. The aim of this study is to investigate the molecular mechanisms of cold nociception in Drosophila melanogaster. A specific subset of peripheral sensory neurons (Class III dendritic arborization (da) neurons), are implicated in Drosophila larvae’s response to noxious cold.

Previous literature has associated a family of gap junction protein, …

Alignment Of Neurochemically Defined Modules In Multimodal Aspects Of The Mouse Inferior Colliculus., Chris H. Dillingham

Senior Honors Projects, 2010-2019

Processing of sound requires precise coordination of various levels of the auditory system. Auditory reflexes and orientation behaviors require interactions with other systems and modalities, emphasizing the importance of highly organized integrative circuits. The inferior colliculus (IC) is a unique midbrain structure in that it exhibits aspects that are specifically arranged for processing auditory cues, as well as regions that handle multisensory inputs and thereby exhibit an entirely different organization. While the central nucleus of the IC (CNIC) is primarily auditory and arranged tonotopically, the lateral cortex (LCIC) is multimodal and exhibits a unique array of modular and extramodular fields. …

The Effects Of Chronic Partial Sleep Deprivation And Chronic Voluntary Alcohol Consumption On Δfos B Accumulation, Kristian Ponder

Masters Theses, 2010-2019

The present study explores the relation between sleep restriction and alcohol use and the neural substrates that result from chronic behaviors. Accumulation of the transcription factors ΔFosB is suggested as a possible outcome of chronic behaviors, such as addiction. Sleep is discussed as possible mediating factor in the relationship between ΔFosB and chronic alcohol consumption. There were four experimental groups in this study: Control (C), Sleep Deprivation only (SD), Alcohol Exposure only (AO), and both sleep deprivation and alcohol exposure (B). Levels of ΔFosB accumulation in the Nucleus Accumbens (NAc) revealed a significant main effect of sleep deprivation, but no …

Ventromedial Prefrontal Cortex Damage Is Associated With Decreased Ventral Striatum Volume And Response To Reward, Maia Pujara, Carissa Philippi, Julian Motzkin, Mustafa Baskaya, Michael Koenigs

Psychology Faculty Works

The ventral striatum and ventromedial prefrontal cortex (vmPFC) are two central nodes of the “reward circuit” of the brain. Human neuroimaging studies have demonstrated coincident activation and functional connectivity between these brain regions, and animal studies have demonstrated that the vmPFC modulates ventral striatum activity. However, there have been no comparable data in humans to address whether the vmPFC may be critical for the reward-related response properties of the ventral striatum. In this study, we used fMRI in five neurosurgical patients with focal vmPFC lesions to test the hypothesis that the vmPFC is necessary for enhancing ventral striatum responses to …

The Tnfα-Transgenic Rat: Hippocampal Synaptic Integrity, Cognition, Function, And Post-Ischemic Cell Loss, L. Creed Pettigrew, Richard J. Kryscio, Christopher M. Norris

Sanders-Brown Center on Aging Faculty Publications

The cytokine, tumor necrosis factor α (TNFα), is a key regulator of neuroinflammation linked to numerous neurodegenerative conditions and diseases. The present study used transgenic rats that overexpress a murine TNFα gene, under the control of its own promoter, to investigate the impact of chronically elevated TNFα on hippocampal synaptic function. Neuronal viability and cognitive recovery in TNFα Tg rats were also determined following an ischemic insult arising from reversible middle cerebral artery occlusion (MCAO). Basal CA3-CA1 synaptic strength, recorded in acute brain slices, was not significantly different between eight-week-old TNFα Tg rats and non-Tg rats. In contrast, slices from …

The Relationship Between Time Of Day, Mood, And Electroencephalography (Eeg) Asymmetry, Morgan Tantillo

Honors Projects

Previous researchers have had success in finding a correlation between exercise and an increase in positive mood. Researchers have also found a correlation between time of day and mood. The current study will explore the relationship between time of day, mood, and electroencephalography (EEG) asymmetry. The study utilized a convenient sample of ten undergraduate students at Bowling Green State University. Participants had baseline EEG recordings taken, and then participated in moderate exercise, followed by another EEG recording. Participants’ mood was assessed through a self-reported mood questionnaire before the condition as well as immediately after. Due to multiple statistical tests, the …

Acth Prevents Deficits In Fear Extinction Associated With Early Life Seizures, Andrew T. Massey, David K. Lerner, Gregory L. Holmes, Rod C. Scott, Amanda Hernan

Dartmouth Scholarship

Objective: Early life seizures (ELS) are often associated with cognitive and psychiatric comorbidities that are detrimental to quality of life. In a rat model of ELS, we explored long-term cognitive outcomes in adult rats. Using ACTH, an endogeneous HPA-axis hormone given to children with severe epilepsy, we sought to prevent cognitive deficits. Through comparisons with dexamethasone, we sought to dissociate the corticosteroid effects of ACTH from other potential mechanisms of action.

Results: Although rats with a history of ELS were able to acquire a conditioned fear learning paradigm and controls, these rats had significant deficits in their ability to extinguish …

Anatomical Markers For Elevated Cognition In Dinosaurs, Thomas Gaetano

Honors Projects

Much research has been conducted on brain evolution within Dinosauria. Dinosaurs were originally believed to be incapable of any advanced cognitive abilities beyond the level observed in modern reptiles. This is likely true for many dinosaurs, but recent discoveries suggest that the non-avian maniraptor dinosaurs shared many physical characteristics with their bird descendants, including body feathers and neural adaptations for flight. By studying cranial endocasts (the braincase of fossilized skulls) using computed tomography (CT), paleontologists are beginning to understand the neural changes that took place across the dinosaur-bird transition. Most of these studies are focused on the development of flight, …

Neurocalcin ẟ Response To Calcium: Which Ef Hand Matters The Most?, Trokon Fiawoo

Graduate School of Biomedical Sciences Theses and Dissertations

Changes in intracellular calcium levels play a very important role in cell signaling, in turn, affecting neuronal functions such as memory, learning and cell death. A class of proteins called Neuronal Calcium Sensor (NCS) proteins serves to modulate the functioning of the neuronal cells in response to changes in calcium levels. Structurally, all NCS proteins have 4 calcium-binding EF hand motifs, although EF I does not bind to calcium in many members. All NCS proteins are myristoylated at the N-terminus. Neurocalcin delta (NCALD) is an NCS protein, and shares 95% similarity in primary amino acid sequence with another major NCS …

Effect Of Zymosan-Induced Peritonitis On The Expression Of Substance P In Primary Sensory Neurons And Spinal Nerve Processes, Michael G. Armstrong

Undergraduate Honors Theses

Macrophages and other cells of the innate immune system recognize foreign particles that could be potentially dangerous and respond by initiating an inflammatory response. The biologically active chemical mediators of this response called pro-inflammatory cytokines are produced in various myeloid derived immune cells and can affect other cells of the body. Interleukin-1β, a pro-inflammatory cytokine, has been shown to have direct effects on dorsal root ganglion (DRG) cell bodies including the upregulation and direct release of a nociceptive neurotransmitter called substance P (SP). Using a zymosan-induced model of systemic inflammation, we hypothesized that murine DRG neurons and the nerve processes …

Exploring The Effect Of Novel Small Molecules On Oligodendrocyte Precursor Proliferation, Sagune Sakya

University Scholar Projects

Gliomas, a type of brain tumor, can be difficult to treat and have a poor survival rate. One pathway that leads to glioma formation is excessive signaling by platelet derived growth factors (PDGF) through PDGF receptor α (PDGFRα). Through this research, I found that novel compounds that downregulate PDGFRα decrease proliferation of Oli-neu cells, an oligodendrocyte precursor cell model, and identified signaling pathways through which these compounds may exert their effect. Further investigation may identify targets for development of glioma treatments.

Evaluation Of Seizure Threshold As An Early Behavioral Marker Of Disease Progression In The Mouse Model Of Mucopolysaccharidosis Iiia, Pamela Santiago

Dissertations, Masters Theses, Capstones, and Culminating Projects

Mucopolysaccharidosis IIIA (MPS IIIA) is a lysosomal storage disease caused by a mutation in the gene that codes for the enzyme heparan sulfamidase. The decreased enzyme activity of heparan sulfamidase results in the accumulation of heparan sulfate (HS). HS accumulation in the brain causes severe central nervous system (CNS) complications, including learning and memory deficits and seizure. MPS IIIA patients have short life expectancies and there currently is no cure for the disease. This thesis work was aimed at identifying an early neurological phenotype in the mouse model of MPS IIIA. The data will aid in the design of an …