Differential Thickening And Thinning Of Auditory Cortex In Deaf Cats Revealed With Ultra-High-Field Mri,
2019
The University of Western Ontario
Differential Thickening And Thinning Of Auditory Cortex In Deaf Cats Revealed With Ultra-High-Field Mri, Stephen G. Gordon
Electronic Thesis and Dissertation Repository
In the absence of hearing, the brain must adapt and repurpose the former auditory cortex. In this study we scanned normal hearing (n=29) and deaf (n=26) cats to identify cortical areas of differing thickness using the auditory regions from a 3D cortical atlas. Compared to hearing controls, differential thickening and thinning was observed in specific regions of the deaf auditory cortex. More dorsal auditory regions tended to be bilaterally thicker in the deaf group, while more ventral regions in the left hemisphere were thinner. The location and nature of these changes creates a gradient along the dorsoventral axis wherein dorsal …
Sensory Perception,
2019
CUNY City College
Sensory Perception, Adrian Rodriguez-Contreras
Open Educational Resources
Different types of sensory systems with their functional modalities will be presented. The biological bases for how these functions are generated and modified will then be described. As vision is the principal means of perception, we will focus in this course most on visual processing. Scientific data will be integrated into the lectures, such that students develop critical skills in analyzing data and proposing hypotheses.
Functional Organization Of Cortical Maps For Ocular Dominance And Light-Dark Polarity In Primary Visual Cortex,
2019
SUNY College of Optometry
Functional Organization Of Cortical Maps For Ocular Dominance And Light-Dark Polarity In Primary Visual Cortex, Sohrab Najafian, Jian Zhong Jin, Jose-Manuel Alonso
MODVIS Workshop
No abstract provided.
The Challenge For Vision Of Fluctuating Real-World Illumination,
2019
University of Manchester
The Challenge For Vision Of Fluctuating Real-World Illumination, David H. Foster
MODVIS Workshop
No abstract provided.
Investigating The Role Of Integrin Beta 3 In Dendritic Arborization In The Supragranular Developing Cerebral Cortex,
2019
James Madison University
Investigating The Role Of Integrin Beta 3 In Dendritic Arborization In The Supragranular Developing Cerebral Cortex, Zachary Logan Holley
Senior Honors Projects, 2010-2019
Integrin subunits have been implicated in axonal and dendritic outgrowth. In particular, a strong positive association has been found between mutations in integrin beta 3 (Itgb3) and autism spectrum disorder, but little is known about neuronal Itgb3 function in vivo. Many forms of autism spectrum disorder are thought to arise from dysfunctional dendritic arborization and synaptic pruning. Global knockout of Itgb3 in mice leads to autistic-like behaviors. Itgb3-/- mice also have reduced callosal volume, a key neuroanatomical correlate of autism. Here, we test the hypothesis that Itgb3 is required for normal dendritic arborization in layer II/III pyramidal …
The Neurophysiological Changes Associated With Motor Learning In Adults And Adolescents,
2019
University of Nebraska Medical Center
The Neurophysiological Changes Associated With Motor Learning In Adults And Adolescents, James E. Gehringer
Theses & Dissertations
One main purpose of this dissertation was to explore how sensorimotor cortical oscillations changed after practicing a novel ankle plantarflexion target matching task. We behaviorally quantified the speed, accuracy, reaction time, velocity, and variability of the participant’s performance of the task, while collecting their neurophysiological responses with magnetoencephalography (MEG). With these data, we assessed how the motor planning and execution stages of movement during a goal directed target matching task changed after practicing a task in typically developing young adults with their non-dominant ankle. We found that the cortical oscillations in the beta frequency range that were sourced from the …
Feedforward And Feedback Signals In The Olfactory System,
2019
University of Arkansas, Fayetteville
Feedforward And Feedback Signals In The Olfactory System, Srimoy Chakraborty
Graduate Theses and Dissertations
The conglomeration of myriad activities in neural systems often results in prominent oscillations. The primary goal of the research presented in this thesis was to study effects of sensory stimulus on the olfactory system of rats, focusing on the olfactory bulb (OB) and the anterior piriform cortex (aPC). Extracellular electrophysiological measurements revealed distinct frequency bands of oscillations in OB and aPC. However, how these oscillatory fluctuations help the animal to process sensory input is not clearly understood. Here we show high frequency oscillations in olfactory bulb carry feedforward signals to anterior piriform cortex whereas feedback from the aPC is predominantly …
Interhemispheric Communication And Lateralization In The Mouse Hippocampus,
2019
The Graduate Center, City University of New York
Interhemispheric Communication And Lateralization In The Mouse Hippocampus, Jake Jordan
Dissertations, Theses, and Capstone Projects
The hippocampus is essential for memory and spatial navigation. Many theories have been proposed to explain how the hippocampus contributes to cognition; however, none has fully explained relevant neurophysiological and behavioral data. Hemispheric lateralization of hippocampal function has been reported in humans and in rodents, and lateralization of hippocampal neural circuitry has been reported in rodents. Most theories of hippocampal function fail to consider the hippocampus as a bilateral structure with hemispheric differences. Further, proposed theories of hippocampal lateralization have their own limitations in explaining empirical data concerning left/right function. Little is known about communication between the hippocampi across hemispheres. …
Acute Social Defeat-Induced Neuroinflammation In The Vmpfc Of Syrian Hamsters Via Microglial Activation,
2019
University of Tennessee, Knoxville
Acute Social Defeat-Induced Neuroinflammation In The Vmpfc Of Syrian Hamsters Via Microglial Activation, Thomas Clarity
EURēCA: Exhibition of Undergraduate Research and Creative Achievement
Research suggests causal relationships between neuroinflammation and stress-related psychopathologies. Exposure to moderate or chronic psychological stress in rodents leads to increased activation of microglia, the brain’s resident immune cells. The ventral medial prefrontal cortex (vmPFC) is a key limbic region involved in top-down regulation of psychological stress and mediates the deleterious effects of microglial activity following prolonged restraint stress. While there is a growing body of literature indicating that chronic social defeat increases microglial activity in the vmPFC, there has been little research investigating the effects of acute social defeat stress. Here, we used an acute social defeat paradigm in …
Ultra-High Field Magnetic Resonance Imaging For Stereotactic Neurosurgery,
2019
The University of Western Ontario
Ultra-High Field Magnetic Resonance Imaging For Stereotactic Neurosurgery, Jonathan Lau
Electronic Thesis and Dissertation Repository
Stereotactic neurosurgery is a subspecialty within neurosurgery concerned with accurate targeting of brain structures. Deep brain stimulation (DBS) is a specific type of stereotaxy in which electrodes are implanted in deep brain structures. It has proven therapeutic efficacy in Parkinson’s disease and Essential Tremor, but with an expanding number of indications under evaluation including Alzheimer’s disease, depression, epilepsy, and obesity, many more Canadians with chronic health conditions may benefit. Accurate surgical targeting is crucial with millimeter deviations resulting in unwanted side effects including muscle contractions, or worse, vessel injury. Lack of adequate visualization of surgical targets with conventional lower field …
Cortical Plasticity Following Adult-Onset Hearing Loss,
2019
The University of Western Ontario
Cortical Plasticity Following Adult-Onset Hearing Loss, Ashley L. Schormans
Electronic Thesis and Dissertation Repository
The consequences of hearing loss are not confined to how the central auditory system processes sound; crossmodal plasticity also occurs, which is characterized by an increased responsiveness of neurons in auditory areas to visual and/or tactile stimuli. In the primary auditory cortex, partial hearing loss causes a decrease in the number of auditory-responsive neurons, as well as an increase in multisensory neurons. However, it was relatively unknown how adult-onset hearing loss affected cortical areas that are already capable of integrating multisensory information, such as the lateral extrastriate visual cortex (V2L). Using a combination of in vivo electrophysiology, neuropharmacology and behavioural …
Influence Of Stimulus Intensity On Multimodal Integration In The Startle Escape System Of Goldfish,
2019
CUNY Hunter College
Influence Of Stimulus Intensity On Multimodal Integration In The Startle Escape System Of Goldfish, Camille Mcintyre, Thomas Preuss
Publications and Research
Processing of multimodal information is essential for an organism to respond to environmental events. However, how multimodal integration in neurons translates into behavior is far from clear. Here, we investigate integration of biologically relevant visual and auditory information in the goldfish startle escape system in which paired Mauthner-cells (M-cells) initiate the behavior. Sound pips and visual looms as well as multimodal combinations of these stimuli were tested for their effectiveness of evoking the startle response. Results showed that adding a low intensity sound early during a visual loom (low visual effectiveness) produced a supralinear increase in startle responsiveness as compared …
Contextually Modulated Avoidance Behavior In Rats Post-Pavlovian Extinction,
2019
CUNY Hunter College
Contextually Modulated Avoidance Behavior In Rats Post-Pavlovian Extinction, Lauren Branigan
Theses and Dissertations
The following study sought to examine the psychological substrates of renewal (e.g.., context dependent extinction processes) for conditioned avoidance behaviors in rats. Using signaled active avoidance conditioning, rats acquired two-way shuttle responding, to two different auditory stimuli. These behaviors were then extinguished through exposure to the auditory stimuli where shuttling behavior was now without consequence. Subjects were then tested for renewal of avoidance in three distinct renewal sequences (e.g., ABA vs ABB, AAB vs AAA, and ABC vs ABB) in three separate groups of rats. It was found that subjects showed more responding to a stimulus presented outside of its …
Post-Synaptic Mechanisms Of Early And Late Prepulse Inhibition In The Goldfish,
2019
The Graduate Center, City University of New York
Post-Synaptic Mechanisms Of Early And Late Prepulse Inhibition In The Goldfish, Daniel Bronson
Dissertations, Theses, and Capstone Projects
Sensorimotor gating, or prepulse inhibition (PPI), attenuates the startle response during sensory processing by limiting sensory input to the startle circuit. In the goldfish startle circuit, a single action potential in the Mauthner-cell (M-cell) triggers the startle response. PPI in the M-cell is mediated by multiple post-synaptic mechanisms, including the activation of a tonic, shunting inhibition as well as a voltage-sensitive conductance, both of which briefly reduce M-cell excitability. However, the specific channels and pathways that modulate PPI are not fully known. This work further characterizes the post-synaptic conductances that mediate PPI by blocking voltage-gated and inward-rectifying potassium channels, antagonizing …
Attentional Selection In Judgments Of Stereo Depth,
2019
Syracuse University
Attentional Selection In Judgments Of Stereo Depth, Bart Farell, Cherlyn J. Ng
Biomedical and Chemical Engineering - All Scholarship
Stereoscopic depth is most useful when it comes from relative rather than absolute disparities. However, the depth perceived from relative disparities can vary with stimulus parameters that have no connection with depth or are irrelevant to the task. We investigated observers’ ability to judge the stereo depth of task-relevant stimuli while ignoring irrelevant stimuli. The calculation of depth from disparity differs for 1-D and 2-D stimuli and we investigated the role this difference plays in observers’ ability to selectively process relevant information. We show that the presence of irrelevant disparities affects perceived depth differently depending on stimulus dimensionality. Observers could …
Timing Is Everything: Temporal Dynamics Of Brain Activity Using The Human Connectome Project,
2019
University of Puget Sound
Timing Is Everything: Temporal Dynamics Of Brain Activity Using The Human Connectome Project, Francesca Lofaro
Summer Research
Most neuroimaging studies produce snapshots of brain activity. The goal of this project is to examine the temporal dynamics of how these areas interact through time, using fear as a case study to assess how regions involved in fear interact. Working with Matlab computer code, I sort through the large fMRI dataset known as the Human Connectome Project to extract neuroimaging data from patients with different NIH Toolbox Fear-Somatic survey scores to assess the temporal dynamics between brain regions. The results will allow an understanding beyond which areas are involved, and instead will provide a picture of how these areas …
The Rhesus Macaque Corticospinal Connectome,
2019
Claremont Colleges
The Rhesus Macaque Corticospinal Connectome, Sydney Talmi
CMC Senior Theses
The corticospinal tract (CST), which carries commands from the cerebral cortex to the spinal cord, is vital to fine motor control. Spinal cord injury (SCI) often damages CST axons, causing loss of motor function, most notably in the hands and legs. Our preliminary work in rats suggests that CST circuitry is complex: neurons whose axons project to the lower cervical spinal cord, which directly controls hand function, also send axon collaterals to other locations in the nervous system and may engage parallel motor systems. To inform research into repair of SCI, we therefore aimed to map the entire projection pattern, …
Role Of Trkb-Signaling In Taste Development And Function.,
2018
University of Louisiville
Role Of Trkb-Signaling In Taste Development And Function., Jennifer Rios-Pilier
Electronic Theses and Dissertations
In the geniculate ganglion, taste neurons likely differentiate into subtypes during development, but very little is known about how these neurons are defined molecularly or how they differentiate. Embryonically, geniculate neuron development is regulated by the growth factor, brain derived neurotrophic factor (BDNF). Postnatally, BDNF becomes restricted to subpopulations of taste receptor cells with specific functions, primarily sour responding. I hypothesized that during development, the receptor for BDNF, tropomyosin kinase B receptor (TrkB), also becomes restricted to a neuronal subset. I used transgenic mouse models to label and quantify both geniculate sensory neurons (Phox2b+), and those expressing TrkB (GFP) across …
Learning Expands The Preplanning Horizon In Finger Sequence Tasks,
2018
The University of Western Ontario
Learning Expands The Preplanning Horizon In Finger Sequence Tasks, Neda Kordjazi
Electronic Thesis and Dissertation Repository
Many everyday skills involve the production of complex sequences of movements. However, the dynamics of the interplay between action selection and execution processes in sequential movements is poorly understood.Here, we set out to investigate the extent to which information regarding upcoming actions is utilized by the motor system to preplan into the future and furthermore, how this ability is influenced by learning. We designed a finger sequence taskwhere participants were shown only a fixed number of upcoming cues regarding future presses in every trial (viewing window, W). W varied between 1 (next digit revealed with pressing the current digit – …
Mapping A Pup-Responsive Pathway From The Medial Preoptic Area To The Ventral Tegmental Area.,
2018
University of Massachusetts Amherst
Mapping A Pup-Responsive Pathway From The Medial Preoptic Area To The Ventral Tegmental Area., Matias Andina
Masters Theses
Maternal behavior is the complex array of caregiving behaviors females display towards offspring. In rats, the transition to motherhood depends on the action of various hormones, especially estradiol near parturition, which primes the maternal circuitry to respond to pups upon first encounter at parturition with appropriate maternal behavior. Although virgin rats avoid pups, new mothers are highly motivated to interact with pups, and their maternal behavior depends on the functional interaction between the medial preoptic area (mPOA) and the ventral tegmental area (VTA). However, a precise mapping of the VTA-projecting mPOA neurons remains to be elucidated. To determine whether pup-responsive …
