Systems Neuroscience Commons^™

The Role Of Glutamate Neurotransmission In The Ventral Tegmental Area In The Expression Of Conditioned Approach Learning, Priscila Hachimine-Merli

All Graduate Works by Year: Dissertations, Theses, and Capstone Projects

Conditioned stimuli (CSs) come to function as CSs by acquiring the capacity to activate the same mesocorticolimbic dopamine (DA) neurons activated by primary rewards, producing conditioned activation of these neurons and their associated motivational states. This model stipulates that CSs activate mesocorticolimbic DA systems through the activation of glutamate receptors on DA neurons in the ventral tegmental area (VTA). We tested the hypothesis that glutamate receptor stimulation in the VTA is necessary for the expression of conditioned approach. Rats were tested in a conditioned approach protocol that consisted of 7 consecutive conditioning sessions (light presentations and food were paired), one ...

Co-Modulation Masking Release Begins In The Auditory Periphery, Kareem R. Hussein, Agudemu Borjigan, Mark Sayles

The Summer Undergraduate Research Fellowship (SURF) Symposium

Understanding speech in noisy environments can be difficult, especially for people with hearing loss. The background noise can cover up the sounds of interest. Normally, the auditory system works to alleviate this problem by tagging and then cancelling the noise. Our experiments are aimed at understanding the mechanism of this noise cancellation process. We hypothesize that non-linear signal processing in the mammalian cochlea (the most peripheral part of the auditory system) is the basis of noise cancellation. To test this hypothesis, we measured the responses of auditory-nerve fibers (ANFs) to sounds embedded in background noise with different statistical properties. ANFs ...

Central And Peripheral Difference In Perceptual Bias In Ambiguous Perception Using Dichoptic Stimuli --- Implications For The Analysis-By-Synthesis Process In Visual Recognition, Li Zhaoping Prof

MODVIS Workshop

No abstract provided.

Similarity-Based Fusion Of Meg And Fmri Discerns Early Feedforward And Feedback Processing In The Ventral Stream, Yalda Mohsenzadeh Dr., Radoslaw Martin Cichy Dr., Aude Oliva Dr., Dimitrios Pantazis Dr.

MODVIS Workshop

Successful models of vision, such as DNNs and HMAX, are inspired by the human visual system, relying on a hierarchical cascade of feedforward transformations akin to the ventral stream. Despite these advances, the human visual cortex remains unique in complexity, with feedforward and feedback pathways characterized by rapid spatiotemporal dynamics as visual information is transformed into semantic content. Thus, a systematic characterization of the spatiotemporal and representational space of the ventral visual pathway can offer novel insights in the duration and sequencing of cognitive processes, suggesting computational constraints and new architectures for computer vision models.

To discern the feedforward and ...

Comparing Diverse V1 Models On The Same Platform: Virtual V1sion, Cheryl Olman

MODVIS Workshop

No abstract provided.

Evaluating And Interpreting A Convolutional Neural Net As A Model Of V4, Dean A. Pospisil, Anitha Pasupathy, Wyeth Bair

MODVIS Workshop

Convolutional neural nets (CNNs) are currently the highest performing image recognition computer algorithms. Of interest is whether these CNNs, following extensive supervised training, perform computations similar to those in the ventral visual stream. We investigated whether CNN units’ tuning for shape boundaries was similar to V4’s as described in the angular position and curvature (APC) model of Pasupathy and Connor 2001. From units in all layers of AlexNet (see Figure A), an object recognition CNN, we recorded responses to the original study’s set of shape stimuli (51 simple closed shapes at up to 8 rotations) presented at 51 ...

How Neural Activity Shapes Decision Making: An Optogenetic Investigation Of The Neural Basis Of Mate Choice In Female Songbirds, Sarah E. Maze

Honors Theses AY 16/17

The intent of this project is to gain new insight into the neural circuitry that underlies decision making through understanding the connection between sensory perception and motor action. This investigation further seeks to identify whether optogenetic manipulation of specific neurons results in a change in mate choice. In defining this connection, the end goal is to combat deleterious decision making behavior in humans, such as drug addiction. Female Bengalese finches (BFs) provide an accessible model in which to investigate the neural mechanisms of behavior. Previous studies reveal that activity in the caudal portion of the mesopallium (CM) in the female ...

Frontal, Amygdalar, And Temporal Convergence In The Primate Ventral Striatum: Implications For Huntington’S Disease, Ellen H. Yates

Undergraduate Honors Theses

Huntington’s disease (HD) is a debilitating neurodegenerative disease that is part of a class of diseases affecting the basal ganglia, a group of subcortical structures in the brain. Impaired negative emotion recognition is a common and early symptom of HD, and entails the patient being unable to properly identify negative emotions on human faces. Through analysis of cell label patterns in a macaque cortex with a retrograde tracer, a region in the ventromedial striatum has been identified with the potential to function as a critical hub in the emotion processing networks. This region of the striatum receives projections from ...

Plateau Potential Fluctuations And Intrinsic Membrane Noise, Daniel Scott Borrus

Undergraduate Honors Theses

This thesis focuses on subthreshold membrane potential fluctuations in the plateau potentials of bistable neurons. Research involved with plateau potentials typically finds one of the resting membrane potentials to be more susceptible to voltage fluctuations. This difference in the amplitude of the membrane potential fluctuations is most often attributed to the voltage-dependent membrane conductance. Occasionally, however, the typically quieter resting membrane potential exhibits larger voltage fluctuations than the expected one. It has been proposed that this increased membrane potential noise is the result of the stochastic gating of the voltage-gated ion channels. In this thesis, we use a simple bistable ...

P35. Investigating The Effect Of Maternal Immune Activation On Sensory Filtering, Social Behaviour And Attention, Faraj Haddad

Western Research Forum

Background

Altered brain development is associated with many neuropsychiatric disorders like Autism Spectrum Disorder (ASD) and schizophrenia. Environmental insults can interfere with neurodevelopment, and a prominent example is maternal infection during pregnancy. Epidemiological studies show that children born to mothers who were infected during pregnancy display a higher risk of developing ASD and schizophrenia, and this effect is mainly due to the maternal immune response. Polyinosinic-polycytidilic acid (Poly I:C) is a double stranded RNA molecule that mimics viral markers and elicits an immune response. When injected in pregnant rodents, this model produces offspring that exhibit core symptoms of ASD ...

Neurotensin Nts1 And Nts2 Receptor Agonists Produce Anxiolytic-Like Effects In The 22-Khz Ultrasonic Vocalization Model In Rats, Floyd F. Steele Iii, Shannon C. Whitehouse, Jacob S. Aday, Adam J. Prus

Journal Articles

Neurotensin is a neuropeptide neurotransmitter that interacts with multiple neurotransmitter systems, including those regulating amygdalar function, via NTS₁ and NTS₂ receptors. Both receptors are expressed in the amygdala and agonists for NTS₁ or NTS₂ receptors have exhibited anxiolytic effects in animal models. Systemic adminstration of NTS₁ receptor agonist PD149163 was recently shown to reduce footshock conditioned 22-kHz ultrasonic vocalizations in rats, suggesting that PD149163 produced an anxiolytic effect. The effects that neurotensin may have or a selective NTS₂receptor agonist may have on 22-kHz vocalizations has yet to be examined. The current study evaluated ...

Rules And Mechanisms For Efficient Two-Stage Learning In Neural Circuits, Tiberiu Teşileanu, Bence Ölveczky, Vijay Balasubramanian

Publications and Research

Trial-and-error learning requires evaluating variable actions and reinforcing successful variants. In songbirds, vocal exploration is induced by LMAN, the output of a basal ganglia-related circuit that also contributes a corrective bias to the vocal output. This bias is gradually consolidated in RA, a motor cortex analogue downstream of LMAN. We develop a new model of such two-stage learning. Using stochastic gradient descent, we derive how the activity in ‘tutor’ circuits (e.g., LMAN) should match plasticity mechanisms in ‘student’ circuits (e.g., RA) to achieve efficient learning. We further describe a reinforcement learning framework through which the tutor can build ...

Evaluating Stressor Controllability Effects In Female Rats, Isabella Fallon

Undergraduate Honors Theses

Women are at a higher risk for developing neuropsychiatric conditions including generalized anxiety disorder, post-traumatic stress disorder, and depression. Moreover, traumatic life events may provoke disease development to a higher degree in women than in men. The mechanisms underlying these differences are unknown, however it has been argued that they emerge, in part, from different coping responses to adverse life events. In humans, factors associated with resilience revolve around coping of which actual or perceived behavioral control over stress is a critical element. Work conducted almost entirely with male rats has demonstrated that behavioral control over stress potently modulates the ...

Canine Emotions As Seen Through Human Social Cognition, Miiamaaria V. Kujala

Animal Sentience: An Interdisciplinary Journal on Animal Feeling

It is not possible to demonstrate that dogs (Canis familiaris) feel emotions, but the same is true for all other species, including our own. The issue must therefore be approached indirectly, using premises similar to those used with humans. Recent methodological advances in canine research reveal what dogs experience and what they derive from the emotions perceptible in others. Dogs attend to social cues, they respond appropriately to the valence of human and dog facial expressions and vocalizations of emotion, and their limbic reward regions respond to the odor of their caretakers. They behave differently according to the emotional situation ...

Protein Kinase M Zeta-Mediated Ltp Maintenance In The Non-Human Primate Hippocampus: A Role For Stress And Serotonergic Signaling In Affective Processing, Sasha L. Fulton

School of Arts & Sciences Theses

Early-Life Stress (ELS) is associated with vulnerability to mood disorder, but it’s not well understood how ELS contributes to deficits in cognitive function. Atypical PKMzeta is critical for LTP maintenance and memory. The current study aims to characterize the ELS phenotype with respect to this key marker of hippocampal LTP.

Maguk Scaffolds Organize A Key Synaptic Complex In Horizontal Cell Processes Contacting Photoreceptors, Alejandro Vila, Ph.D.

UT GSBS Dissertations and Theses (Open Access)

Synaptic processes and plasticity of synapses are mediated by large suites of proteins. In most cases, many of these proteins are tethered together by synaptic scaffold proteins. Scaffold proteins have a large number and typically a variety of protein interaction domains that allow many different proteins to be assembled into functional complexes. As each scaffold protein has a different set of protein interaction domains and a unique set of interacting partners, the presence of synaptic scaffolds can provide insight into the molecular mechanisms that regulate synaptic processes. In studies of rabbit retina, we found SAP102 and Chapsyn110 selectively localized in ...

Zombies, Predatory Wasps And Consciousness, James K. Peterson

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.

Synchronization Of Coupled Neurons Via Robust Feedback, Hector Puebla, Ricardo Aguilar-Lopez, Priti Kumar Roy

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.

Cromwell Relative Reward Striatal Activity.Pdf, Howard C. Cromwell, Emily S. Webber, David E. Mankin

Howard Casey Cromwell

Role Of Anterior Cingulate Cortex In Saccade Control, Sahand Babapoor-Farrokhran

Electronic Thesis and Dissertation Repository

Cognitive control is referred to the guidance of behavior based on internal goals rather than external stimuli. It has been postulated that prefrontal cortex is mainly involved in higher order cognitive functions. Specifically, anterior cingulate cortex (ACC), which is part of the prefrontal cortex, is suggested to be involved in performance monitoring and conflict monitoring that are considered to be cognitive control functions.

Saccades are the fast eye movements that align the fovea on the objects of interest in the environment. In this thesis, I have explored the role of ACC in control of saccadic eye movements. First, I performed ...