Open Access. Powered by Scholars. Published by Universities.®

Neuroscience and Neurobiology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Behavioral Neurobiology

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 481 - 510 of 884

Full-Text Articles in Neuroscience and Neurobiology

Differences In Habenula Kisspeptin Expression And Its Effects On Stress Coping Styles In Zebrafish, Danio Rerio, Andrew Wahl Mar 2018

Differences In Habenula Kisspeptin Expression And Its Effects On Stress Coping Styles In Zebrafish, Danio Rerio, Andrew Wahl

UNO Student Research and Creative Activity Fair

Two particular styles of stress coping behaviors have been identified as evolutionarily conserved across vertebrate species and are referred to as proactive and reactive. Reactive and proactive stress coping styles have distinct 5-HT expression profiles with greater expression of 5-HT found in proactive individuals. It was previously shown that kiss1 expression in the ventral habenula (vHb) presynaptically activates kiss-r1 which can alter glutamatergic levels in co-localizing cells in the vHb that terminate in the median raphe (MR). This can directly or indirectly increase 5-HT expression in the MR via glutamate. It is unknown whether kisspeptin expression in the vHb can …


The Convergence Of Psychology And Neurobiology In Flavor-Nutrient Learning, Kevin P. Myers Mar 2018

The Convergence Of Psychology And Neurobiology In Flavor-Nutrient Learning, Kevin P. Myers

Faculty Journal Articles

Flavor evaluation is influenced by learning from experience with foods. One main influence is flavor-nutrient learning (FNL), a Pavlovian process whereby a flavor acts as a conditioned stimulus (CS) that becomes associated with the postingestive effects of ingested nutrients (the US). As a result that flavor becomes preferred and intake typically increases. This learning powerfully influences food choice and meal patterning. This paper summarizes how research elucidating the physiological and neural substrates of FNL has progressed in parallel with work characterizing how FNL affects perception, motivation, and behavior. The picture that emerges from this work is of a robust system …


Binge Alcohol Exposure Causes Neurobehavioral Deficits And Gsk3Β Activation In The Hippocampus Of Adolescent Rats, Zhe Ji, Lin Yuan, Xiong Lu, Hanqing Ding, Jia Luo, Zun-Ji Ke Feb 2018

Binge Alcohol Exposure Causes Neurobehavioral Deficits And Gsk3Β Activation In The Hippocampus Of Adolescent Rats, Zhe Ji, Lin Yuan, Xiong Lu, Hanqing Ding, Jia Luo, Zun-Ji Ke

Pharmacology and Nutritional Sciences Faculty Publications

Heavy alcohol exposure causes profound damage to the adolescent brain, particularly the hippocampus, which underlie some behavioral deficits. However, the underlying molecular mechanisms remain inconclusive. The current study sought to determine whether binge alcohol exposure affects the hippocampus-related behaviors and key signaling proteins that may mediate alcohol neurotoxicity in adolescent rats. Alcohol exposure reduced the number of both NeuN-positive and doublecortin-positive cells in the hippocampus. Alcohol also induced neurodegeneration which was confirmed by ultrastructural analysis by electronic microscopy and was accompanied with the activation of microglia. Binge alcohol exposure impaired spatial learning and memory which was evaluated by the Morris …


The Winding Road To Relapse: Forging A New Understanding Of Cue-Induced Reinstatement Models And Their Associated Neural Mechanisms, Mark D. Namba, Seven E. Tomek, M. Foster Olive, Joshua S. Beckmann, Cassandra D. Gipson Feb 2018

The Winding Road To Relapse: Forging A New Understanding Of Cue-Induced Reinstatement Models And Their Associated Neural Mechanisms, Mark D. Namba, Seven E. Tomek, M. Foster Olive, Joshua S. Beckmann, Cassandra D. Gipson

Psychology Faculty Publications

In drug addiction, cues previously associated with drug use can produce craving and frequently trigger the resumption of drug taking in individuals vulnerable to relapse. Environmental stimuli associated with drugs or natural reinforcers can become reliably conditioned to increase behavior that was previously reinforced. In preclinical models of addiction, these cues enhance both drug self-administration and reinstatement of drug seeking. In this review, we will dissociate the roles of conditioned stimuli as reinforcers from their modulatory or discriminative functions in producing drug-seeking behavior. As well, we will examine possible differences in neurobiological encoding underlying these functional differences. Specifically, we will …


Neonatal Stimulation Of Pkc Epsilon Signaling Normalizes Fragile X-Associated Deficits In Pvn Oxytocin Expression And Later-Life Social And Anxiety Behavior, Alexandra E. Marsillo Feb 2018

Neonatal Stimulation Of Pkc Epsilon Signaling Normalizes Fragile X-Associated Deficits In Pvn Oxytocin Expression And Later-Life Social And Anxiety Behavior, Alexandra E. Marsillo

Dissertations, Theses, and Capstone Projects

Fragile X Syndrome (FXS) is an inherited developmental disorder characterized by disturbances in emotional and social behavior. Our studies have revealed suppressed hippocampal PKCε expression in Fmr1 knockout (KO) mice, the leading model of FXS. To compensate for this deficiency, we stimulated PKCε in neonatal KO mice by administering a selective PKCε activator, dicyclopropyl-linoleic acid (DCP-LA), and studied its effect on ventral hippocampal neurons and a proximal target of the ventral hippocampus, the hypothalamus, which regulates social and emotional behavior. We observed that at postnatal day 18 (P18), vehicle-treated KO mice displayed increased surface localization of the 3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) …


Social Influences On Songbird Behavior: From Song Learning To Motion Coordination, Iva Ljubičić Feb 2018

Social Influences On Songbird Behavior: From Song Learning To Motion Coordination, Iva Ljubičić

Dissertations, Theses, and Capstone Projects

Social animals learn during development how to integrate successfully into their group. How do social interactions combine to maintain group cohesion? We first review how social environments can influence the development of vocal learners, such as songbirds and humans (Chapter 1). To bypass the complexity of natural social interactions and gain experimental control, we developed Virtual Social Environments, surrounding the bird with videos of manipulated playbacks. This way we were able to design sensory and social scenarios and test how social zebra finches adjust their behavior (Chapters 2 & 3). A serious challenge is that the color output of a …


Discerning Suicide In Drug Intoxication Deaths: Paucity And Primacy Of Suicide Notes And Psychiatric History, Ian Rh Rockett, Eric D. Caine, Hilary S. Connery, Gail D'Onofrio, David J. Gunnell, Ted R. Miller, Kurt B. Nolte, Mark S. Kaplan, Nestor D. Kapusta, Christa L. Lilly, Lewis S. Nelson, Sandra L. Putnam, Steven Stack, Peeter Varnik, Lynne R. Webster, Haomiao Jia Jan 2018

Discerning Suicide In Drug Intoxication Deaths: Paucity And Primacy Of Suicide Notes And Psychiatric History, Ian Rh Rockett, Eric D. Caine, Hilary S. Connery, Gail D'Onofrio, David J. Gunnell, Ted R. Miller, Kurt B. Nolte, Mark S. Kaplan, Nestor D. Kapusta, Christa L. Lilly, Lewis S. Nelson, Sandra L. Putnam, Steven Stack, Peeter Varnik, Lynne R. Webster, Haomiao Jia

Faculty & Staff Scholarship

Objective

A paucity of corroborative psychological and psychiatric evidence may be inhibiting detec- tion of drug intoxication suicides in the United States. We evaluated the relative importance of suicide notes and psychiatric history in the classification of suicide by drug intoxication versus firearm (gunshot wound) plus hanging/suffocation—the other two major, but overtly violent methods.

Methods

This observational multilevel (individual/county), multivariable study employed a general- ized linear mixed model (GLMM) to analyze pooled suicides and undetermined intent deaths, as possible suicides, among the population aged 15 years and older in the 17 states participating in the National Violent Death Reporting System …


Test Of Bpa's Estrogenic Effects On Brain Aromatase Expression, Neural Activity, And Locomotive Behavior In Zebrafish Larvae, Ryan J. Mcauley Jan 2018

Test Of Bpa's Estrogenic Effects On Brain Aromatase Expression, Neural Activity, And Locomotive Behavior In Zebrafish Larvae, Ryan J. Mcauley

Cal Poly Humboldt theses and projects

Bisphenol A (BPA) is a well-known endocrine disrupting chemical that mimics the effects of estrogens. Aromatase B (Cyp19a1b) is a brain-specific enzyme that converts testosterone to estrogen and is highly upregulated in response to estrogen receptor activation localized to radial glial cells. During embryonic zebrafish development, there is a small window of time denoted by an increase in neurogenesis and estrogen receptor activity. Previous studies have demonstrated that a low dose BPA exposure (0.1µM) during this window causes hyperlocomotion in larval zebrafish, yet no further explanation for this behavior change has been described. The purpose of this study was to …


Disc1 Knockout Rats Reveal Sexually Dimorphic Patterns Of Impairment Across Development, Stephanie S. Desrochers Jan 2018

Disc1 Knockout Rats Reveal Sexually Dimorphic Patterns Of Impairment Across Development, Stephanie S. Desrochers

Honors Theses

Schizophrenia is a chronic disorder characterized by three symptom categories: positive (hallucinations, delusions), negative (anhedonia, anxiety), and cognitive (sensory processing and memory deficits). We worked with a biallelic deletion of the Disrupted-in-schizophrenia-1 (DISC1) gene in Sprague-Dawley rats to facilitate our understanding of the biological bases of schizophrenia. Mutations of DISC1 are associated with a higher prevalence of schizophrenia. Adult DISC1 knockout, compared to wildtype, rats display features of schizophrenia-like outcomes in rodent models. The present study investigated the progression of the cognitive symptom deficits in prepulse inhibition (PPI), assessing animals at postnatal days 17 (pre-weaning), 26 (post-weaning), 39 (adolescent), and …


Functional Investigation Of A Brainstem Excitatory Connection Relevant To Sensorimotor Gating, Luis Enrique Martinetti Jan 2018

Functional Investigation Of A Brainstem Excitatory Connection Relevant To Sensorimotor Gating, Luis Enrique Martinetti

Open Access Theses & Dissertations

To focus attention, our brain has to "gate" or block irrelevant sensory information that could lead to brain overload. This is done by way of a neuronal pre-attentive mechanism termed sensorimotor gating (SG). Therefore, deficits in the SG mechanism prevent patients from focusing attention. SG deficits have been observed in patients suffering from various neurological disorders, and it is a hallmark of schizophrenia. Previous work has identified key brain areas, such as the pedunculopontine tegmental nucleus (PPTg), that send inputs to the brainstem to regulate SG. However, there is still a knowledge gap concerning what cell types are involved and …


Insulin Modulates The Strong Reinforcing Effects Of Nicotine And Changes In Insulin Biomarkers In A Rodent Model Of Diabetes, Bryan Cruz Jan 2018

Insulin Modulates The Strong Reinforcing Effects Of Nicotine And Changes In Insulin Biomarkers In A Rodent Model Of Diabetes, Bryan Cruz

Open Access Theses & Dissertations

This study examined whether the strong reinforcing effects of nicotine and changes in insulin biomarkers observed in diabetic rats are modulated via insulin. A model of diabetes was employed involving administration of streptozotocin (STZ), which produces hypoinsulinemia in rats. The present study included vehicle- or STZ-treated rats that received sham surgery or an insulin pellet. Two-weeks later, the rats were given extended access to intravenous self-administration (IVSA) of saline or nicotine. Concomitant changes in food intake, water responses, and body weight were assessed during 12 days of IVSA. After the last session, plasma levels of insulin, leptin, amylin, and glucagon-like …


Only The Human Brain Has The Cognitive Capacity For Jealousy, Donatella Marazziti Jan 2018

Only The Human Brain Has The Cognitive Capacity For Jealousy, Donatella Marazziti

Animal Sentience

Jealousy is exclusively a human phenomenon because nonhuman animals lack the brain structures regulating the higher processes underlying jealousy.


Single Olfactory Receptors Set Odor Detection Thresholds, Adam Dewan, Annika Cichy, Jingji Zhang, Kayla Miguel, Paul Feinstein, Dmitry Rinberg, Thomas Bozza Jan 2018

Single Olfactory Receptors Set Odor Detection Thresholds, Adam Dewan, Annika Cichy, Jingji Zhang, Kayla Miguel, Paul Feinstein, Dmitry Rinberg, Thomas Bozza

Publications and Research

In many species, survival depends on olfaction, yet the mechanisms that underlie olfactory sensitivity are not well understood. Here we examine how a conserved subset of olfactory receptors, the trace amine-associated receptors (TAARs), determine odor detection thresholds of mice to amines. We find that deleting all TAARs, or even single TAARs, results in significant odor detection deficits. This finding is not limited to TAARs, as the deletion of a canonical odorant receptor reduced behavioral sensitivity to its preferred ligand. Remarkably, behavioral threshold is set solely by the most sensitive receptor, with no contribution from other highly sensitive receptors. In addition, …


Potential Candidates For Treating Deficits Associated With Developmental Ethanol Exposure In A Rodent Model: Solidago Nemoralis & Dimethoxybenzylidene-Anabasine, Logan James Fields Jan 2018

Potential Candidates For Treating Deficits Associated With Developmental Ethanol Exposure In A Rodent Model: Solidago Nemoralis & Dimethoxybenzylidene-Anabasine, Logan James Fields

Theses and Dissertations--Psychology

Prenatal alcohol exposure (Fetal Alcohol Syndrome [FAS] and Fetal Alcohol Spectrum Disorders [FASD’s]) represents the leading preventable cause of intellectual disabilities in the western world, with FASDs estimated to affect approximately 2-5% of live births in the United States at an approximate annual cost of $3.6 billion (CDC, 2015; May et al., 2009). Ethanol (ETOH) exposure during development can lead to a variety of long-term behavioral impairments including problems with executive functioning, motor coordination, spatial learning, attention, and hyperactivity (Jones, 2011; Mattson & Riley, 1998). Much research has been conducted to develop pharmacological and/or environmental interventions to reduce these deficits, …


Effects Of Daily Forced Exercise On Anxiety Of Zebrafish (Danio Rerio) Living In Impoverished Environments, Meagan Collins Jan 2018

Effects Of Daily Forced Exercise On Anxiety Of Zebrafish (Danio Rerio) Living In Impoverished Environments, Meagan Collins

Undergraduate Theses and Capstone Projects

The purpose of this research was to investigate the effects of forced exercise on anxiogenic behavior in Danio rerio living in different environmental conditions. To study this relationship, zebrafish were introduced to the following housing environments for several weeks. Fish in Group 1 were exposed to brown gravel and green, plastic plants (enriched environment), and fish in Group 2 were exposed to no brown gravel and no green, plastic plants (impoverished, structurally-barren environment). Fish from both housing environments were randomly assigned to be exposed to exercise or no exercise (control). Fish in the exercise group were forced to swim against …


Spatial Learning And Memory In Brain-Injured And Non-Injured Mice: Investigating The Roles Of Diacylglycerol Lipase-Α And -Β., Lesley D. Schurman Jan 2018

Spatial Learning And Memory In Brain-Injured And Non-Injured Mice: Investigating The Roles Of Diacylglycerol Lipase-Α And -Β., Lesley D. Schurman

Theses and Dissertations

A growing body of evidence implicates the importance of the endogenous cannabinoid 2-arachidonyl glycerol (2-AG) in memory regulation. The biosynthesis of 2-AG occurs primarily through the diacylglycerol lipases (DAGL-α and -β), with 2-AG serving as a bioactive lipid to both activate cannabinoid receptors and as a rate limiting precursor for the production of arachidonic acid and subsequent pro-inflammatory mediators. Gene deletion of DAGL-α shows decrements in synaptic plasticity and hippocampal neurogenesis suggesting this biosynthetic enzyme may be important for processes of normal spatial memory. Additionally, 2-AG is elevated in response to pathogenic events such as traumatic brain injury (TBI), suggesting …


Complexities Of Chronic Opioid Exposure, Maciej Gonek Jan 2018

Complexities Of Chronic Opioid Exposure, Maciej Gonek

Theses and Dissertations

Studies on repeated exposure to opioids have been carried out for decades yet the mechanisms for certain phenomena such as tolerance are still not fully understood. Furthermore, different medications, such as frequently prescribed benzodiazepines, or different disease states, such as HIV, have their own effects and interactions with chronic opioid exposure that are not fully understood. The overall objective of this dissertation was to investigate the complexities of chronic opioid exposure and how different disease states and medications may modulate the effects of chronic opioids. Our findings demonstrate that the administration of diazepam, at doses that are not antinociceptive or …


Sentience In Fishes: More On The Evidence, Michael L. Woodruff Jan 2018

Sentience In Fishes: More On The Evidence, Michael L. Woodruff

Animal Sentience

In my target article, I argued that the brains of ray-finned fishes of the teleost subclass (Actinopterygii) are sufficiently complex to support sentience — that these fishes have subjective awareness of interoceptive and exteroceptive sense experience. Extending previous theories centered on the tectum, I focused on the organization of the fish pallium. In this Response to the commentaries, I clarify that I do not propose that the fish pallium is, or must be, homologous to the mammalian neocortex to play a role in sentience. Some form of a functionalist approach to explaining the neural basis of sentience across taxa is …


Possible Breakdown Of Dopamine Receptor Synergism In A Mouse Model Of Huntington's Disease, Samantha F. Kennedy Dec 2017

Possible Breakdown Of Dopamine Receptor Synergism In A Mouse Model Of Huntington's Disease, Samantha F. Kennedy

LSU New Orleans Theses and Dissertations

The model of basal ganglia function proposed by Albin, Young and Penney (1989) describes two anatomically independent motor pathways, the direct and indirect. However, under normal conditions striatal dopamine (DA) is required for the expression of motor behavior, and DAergic control of the two pathways (via D1 and D2 receptors, respectively) is dependent on co-activation. We tested for a possible breakdown of D1/D2 synergism using transgenic R6/1 mice bearing the human huntingtin allele (Htt). Motor stereotypy, observed prior to the onset of HD-related symptoms, was rated on a 5-point scale following activation of: A) D1 receptors alone, B) D2 receptors …


Virtual Reality As A Training Tool To Treat Physical Inactivity In Children, Adam W. Kiefer, David Pincus, Michael J. Richardson, Gregory D. Myer Dec 2017

Virtual Reality As A Training Tool To Treat Physical Inactivity In Children, Adam W. Kiefer, David Pincus, Michael J. Richardson, Gregory D. Myer

Psychology Faculty Articles and Research

Lack of adequate physical activity in children is an epidemic that can result in obesity and other poor health outcomes across the lifespan. Physical activity interventions focused on motor skill competence continue to be developed, but some interventions, such as neuromuscular training (NMT), may be limited in how early they can be implemented due to dependence on the child’s level of cognitive and perceptual-motor development. Early implementation of motor-rich activities that support motor skill development in children is critical for the development of healthy levels of physical activity that carry through into adulthood. Virtual reality (VR) training may be beneficial …


Disruption Of Hippocampal Multisynaptic Networks By General Anesthetics., Min-Ching Kuo, L Stan Leung Nov 2017

Disruption Of Hippocampal Multisynaptic Networks By General Anesthetics., Min-Ching Kuo, L Stan Leung

Physiology and Pharmacology Publications

BACKGROUND: Previous studies showed that synaptic transmission is affected by general anesthetics, but an anesthetic dose response in freely moving animals has not been done. The hippocampus provides a neural network for the evaluation of isoflurane and pentobarbital on multisynaptic transmission that is relevant to memory function.

METHODS: Male Long-Evans rats were implanted with multichannel and single electrodes in the hippocampus. Spontaneous local field potentials and evoked field potentials were recorded in freely behaving rats before (baseline) and after various doses of isoflurane (0.25 to 1.5%) and sodium pentobarbital (10 mg/kg intraperitoneal).

RESULTS: Monosynaptic population excitatory postsynaptic potentials at the …


Machine Learning Analysis Identifies Drosophila Grunge/Atrophin As An Important Learning And Memory Gene Required For Memory Retention And Social Learning, Balint Kacsoh Oct 2017

Machine Learning Analysis Identifies Drosophila Grunge/Atrophin As An Important Learning And Memory Gene Required For Memory Retention And Social Learning, Balint Kacsoh

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


The Role Of Glutamate Neurotransmission In The Ventral Tegmental Area In The Expression Of Conditioned Approach Learning, Priscila Hachimine-Merli Sep 2017

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

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 …


Regulation Of The Amyloid Precursor Protein By Prostaglandin J2, A Mediator Of Inflammation: Relevance To Alzheimer’S Disease, Teneka L. Jean-Louis Sep 2017

Regulation Of The Amyloid Precursor Protein By Prostaglandin J2, A Mediator Of Inflammation: Relevance To Alzheimer’S Disease, Teneka L. Jean-Louis

Dissertations, Theses, and Capstone Projects

Inflammation plays a major role in Alzheimer’s disease (AD). Investigating how specific mediators of inflammation contribute to neurodegeneration in AD is crucial. Our studies focused on cyclooxygenases, which are key enzymes in inflammation and highly relevant to AD. Cyclooxygenases (COX -1, constitutive; COX-2, inducible) have emerged as important determinants of AD pathogenesis and progression. COX-2 is highly induced in AD, correlating with AD severity, and COX-1 is also involved in AD. Cyclooxygenases are the rate-limiting enzymes that convert arachidonic acid into prostaglandins (PGs), the principal mediators of CNS neuroinflammation.

The overall GOAL of these studies was to address the mechanisms …


The Nucleus Accumbens Core Dopamine D1 And Glutamate Ampa/Nmda Receptors Play A Transient Role In The Performance Of Pavlovian Approach Behavior, Veronica Dobrovitsky Sep 2017

The Nucleus Accumbens Core Dopamine D1 And Glutamate Ampa/Nmda Receptors Play A Transient Role In The Performance Of Pavlovian Approach Behavior, Veronica Dobrovitsky

Dissertations, Theses, and Capstone Projects

The role of the nucleus accumbens core (NAc core) continues to be redefined with newly acquired data on neurochemical mechanisms mediating the learning and performance of behavior. Previous empirical data showed that dopamine transmission at the D1 receptor (D1R) plays a transient role in the expression of learned Pavlovian approach behavior. Here we show that, prior to overtraining, dopamine activity at D1Rs specifically within the NAc core is critical for the performance of approach behavior elicited by the recently-acquired reward-paired cue. Blockade of D1Rs in the NAc core, but not the dorsomedial striatum or NAc shell, disrupted approach responses during …


Distribution And Activation Of Catecholaminergic Neurons In The Brain Of Male Plainfin Midshipman Fish: Divergence In Behavior And Reproductive Phenotype, Zachary Ghahramani Sep 2017

Distribution And Activation Of Catecholaminergic Neurons In The Brain Of Male Plainfin Midshipman Fish: Divergence In Behavior And Reproductive Phenotype, Zachary Ghahramani

Dissertations, Theses, and Capstone Projects

The plainfin midshipman fish, Porichthys notatus, provides an excellent opportunity for delimiting the influence of neurochemical content on vertebrate vocal behavior, in part because the production and recognition of social-acoustic signals is vital to their reproductive behavior. There are two distinct reproductive male morphs that follow divergent developmental trajectories with corresponding alternative reproductive tactics: type I males are the territorial/nesting morph that vocally court females during the summer breeding season while type II males do not court females, but instead sneak spawn in competition with type I males. Catecholaminergic neurons, which synthesize and release the neurotransmitters dopamine or noradrenaline, …


Behavioral Responses To Pulses Of Light In The Longfin Inshore Squid, Doryteuthis Pealeii (Lesueur, 1821), Stavros P. Hadjisolomou Sep 2017

Behavioral Responses To Pulses Of Light In The Longfin Inshore Squid, Doryteuthis Pealeii (Lesueur, 1821), Stavros P. Hadjisolomou

Dissertations, Theses, and Capstone Projects

The coleoid cephalopods (octopus, squid, and cuttlefish) are masters of rapid, adaptive camouflage. Unlike the slower hormonal chromatophore control of flatfish and chameleons, coleoid mollusks can change body patterns in milliseconds. Visual camouflage in coleoids is driven by a sensorimotor system consisting of visual input of their surroundings, a sophisticated central nervous system for information processing, and a neuromuscular control for body patterning. Motor neurons selectively activate millions of muscles, alternately expanding and reducing the pigmented chromatophores to generate visible brown, red, orange and yellow patterns on the skin. Below the chromatophore-layered skin are two types of reflecting cells, iridophores …


Modulation Of Spasticity By Trans-Spinal Direct Current Stimulation In Animals With Spinal Cord Injury, Wagdy Mekhael Sep 2017

Modulation Of Spasticity By Trans-Spinal Direct Current Stimulation In Animals With Spinal Cord Injury, Wagdy Mekhael

Dissertations, Theses, and Capstone Projects

Central nervous system injuries usually produce motor impairments that are exacerbated by pathologically altered muscle tone. Abnormal muscle tone interferes with voluntary movement and is associated with loss of dexterity. Prior work in our laboratory demonstrated that 30-second trans-spinal direct current (DC) stimulation can temporarily modify muscle tone in anesthetized spastic mice after spinal cord injury (SCI). These experiments described DC-induced muscle tone responses to be polarity-dependent. That is, anodal stimulation (current passed from the lumbar spine to sciatic nerve) decreased muscle tone, and cathodal stimulation (current passed from the sciatic nerve to the lumbar spine) increased it. The present …


Song Rhythm Development In Zebra Finches, Julia Hyland Bruno Sep 2017

Song Rhythm Development In Zebra Finches, Julia Hyland Bruno

Dissertations, Theses, and Capstone Projects

This dissertation investigates song-rhythm learning in songbirds. Songbirds have been studied extensively in mechanistic investigations into the sensorimotor underpinnings of the cultural transmission of learned vocalizations. While several studies identified forebrain song-system neurons that generate rhythmic song patterns, we know little about how song rhythms are learned. The first part of the dissertation describes methods for detecting and analyzing birdsong rhythm patterns, and demonstrates their utility for identifying the role of song rhythms in social interactions. Results suggest that rhythm plasticity in zebra finch song may provide a potential vehicle for communication. Controlled song-learning experiments further found that developing zebra …


A Touchscreen Assay To Probe The Role Of The Serotonergic System In Learning And Visual Information Processing, Jeffrey M. Dorsch, Alexandr Pak, Alexander A. Chubykin Aug 2017

A Touchscreen Assay To Probe The Role Of The Serotonergic System In Learning And Visual Information Processing, Jeffrey M. Dorsch, Alexandr Pak, Alexander A. Chubykin

The Summer Undergraduate Research Fellowship (SURF) Symposium

The neurotransmitter serotonin is involved in numerous processes in the brain such as behavior, learning, memory, mood, and neurodevelopment. Serotonin signaling is regulated by the serotonin transporter protein (SERT), which maintains normal serotonin levels. Mutations in the SERT gene are known to correlate with cognitive and behavioral deficits seen in psychiatric disorders, such as anxiety disorders, depression, and autism spectrum disorder. Researchers study these deficits using SERT knockout (KO) mice, a model that lacks functional SERT and displays changes in anxiety, learning, and motivation. We are interested in how the absence of SERT affects visual processing and learning. A popular …