Behavioral Neurobiology Commons^™

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, …

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

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 …

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 …

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 …

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 …

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 …

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, …

Dopamine D1 And D3 Receptor Polypharmacology In Cocaine Reward And Cocaine Seeking, Ewa J. Galaj

Dissertations, Theses, and Capstone Projects

Background: In the search for efficacious pharmacotherapies to treat cocaine addiction much attention has been given to agents targeting D1 or D3 receptors because of the involvement of these receptors in cocaine-related behaviors. D1 and D3 receptor partial agonists and antagonists have been shown to reduce cocaine reward, reinstatement of cocaine seeking and conditioned place preference (CPP) in rodents and non-human primates. However, translation of these encouraging results with selective D1 or D3 receptor agents has been limited due to a number of factors including toxicity, poor pharmacokinetic properties and extrapyramidal and sedative side effects.

Purpose: Given the …

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

Theses and Dissertations

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.

Adult Neurogenesis In Avian Auditory Cortex, Caudomedial Nidopallium (Ncm): Lateralization And Effects Of Statins, Shuk C. Tsoi

Dissertations, Theses, and Capstone Projects

In the first part of this paper, we investigated the basic relationship between learning, memory and adult neurogenesis using zebra finches. We found that in the auditory cortex, the left hemisphere had more new neurons than the right hemisphere. This lateralization was correlated with song learning and memory. In the second part, we used juvenile zebra finches as a model organism to study the effects of Lipitor on learning, memory and neurogenesis. We found that Lipitor impaired song learning and memory storage. Lipitor treatments also changed the morphology of new neurons and size of old neurons, suggesting statins may affect …

Neurodevelopmental Defects Associated With Gestational Exposure To Low Levels Of Dbp In Mice, Françoise Sidime

Dissertations, Theses, and Capstone Projects

The etiology of autism is thought to involve the complex interplay among genetic and environmental factors. Patterns of inheritance suggest an epigenetic component to the development of autism. A variety of environmental risk factors are known to induce epigenetic changes in DNA, affecting many genes including those autism-associated genes (AAG). The plasticizer dibutyl phthalate (DBP; CAS 84-74-2) is a developmental and reproductive toxin that causes a broad range of birth defects resulting in neurological impairments.

To date, although the effect of DBP as an endocrine and a reproductive disruptor are established, there are only few studies that address the effects …

Status Signaling And The Characterization Of A Chirp-Like Signal In The Weakly Electric Fish Steatogenys Elegans, Caitlin E. Field

Dissertations, Theses, and Capstone Projects

Sensory systems are critical to both exploratory and communicatory processes, the study of which is critical to our understanding of how animals perceive and respond to their environments. In weakly electric fishes the electrosensory system is utilized for both of these purposes. One type of communication, status signaling, is widespread across taxa and frequently hormonally modulated. This hormonal modulation keeps the signal honest, wherein the status of the sender and the production of the status signal itself are both hormone dependent. We investigated exploratory and communicatory strategies of the electromotor system in pulse-type gymnotiforms, with a focus on status communication …

Glycine And Gabaa Receptors Mediate Tonic And Phasic Inhibitory Processes That Contribute To Prepulse Inhibition In The Goldfish Startle Network, Paul C.P. Curtin, Thomas Preuss

Publications and Research

Prepulse inhibition (PPI) is understood as a sensorimotor gating process that attenuates sensory flow to the startle pathway during early stages (20--1000 ms) of information processing. Here, we applied in vivo electrophysiology and pharmacology to determine if PPI is mediated by glycine receptors (GlyRs) and/or GABAA receptors (GABAARs) in the goldfish auditory startle circuit. Specifically, we used selective antagonists to dissect the contributions of target receptors on sound-evoked postsynaptic potentials (PSPs) recorded in the neurons that initiate startle, the Mauthner-cells (M-cell). We found that strychnine, a GlyR antagonist, disrupted a fast-activated (5 ms) and rapidly (<50 >ms) decaying (feed-forward) inhibitory …

Physiological And Subjective Aspects Of Positive Mood In Relation To Executive Functioning: The Potential Moderating Role Of Personality, Luz Helena Ospina

Dissertations, Theses, and Capstone Projects

Positive affect has been demonstrated to improve aspects of cognition. However, recent studies reveal that positive affect may hinder the same cognitive processes, such as executive functioning, memory and creativity. These discrepant findings may be due to differing levels of physiological arousal, a component of the circumplex model of affect, which has been largely ignored in affective research. For example, one recent study suggests that positive valence coupled with varying levels of physiological arousal (i.e., low, moderate, and high) may differentially affect performance on tasks of verbal fluency and memory. Furthermore, one other explanation for these inconsistent findings may relate …

Psychic Collapse And Traumatic Defense: How The Mind Mediates Trauma Living In The Body, Patricia Kim Yoon

Dissertations, Theses, and Capstone Projects

The aim of this exploratory study was to link psychoanalytic theories of trauma and its impact on the mind with psychobiological research of how trauma lives in the body. The study has expanded on prior research (Cramer, 2003) to evidence that defense mechanisms do in fact moderate the relationship between stress and physiological response, and that there are likely individual differences in physiological response to traumatic stress. This study goes further to identify the psychological concomitants of these individual differences within an adult population exposed to potentially traumatic events (PTEs), and their proclivity for using different defense mechanisms. Defense use …

A Behavioral And Biopsychological Investigation Of The Role Of The Illusion Of Control And Perseverative Chasing Between Problem And Non-Problem Gamblers, Brett Evan Bauchner

Dissertations, Theses, and Capstone Projects

The illusion of control is associated with problem gambling. The perception that one is in control of a random event, when in reality there is no control, can facilitate problem gambling behaviors. The degree or extent of control may activate physiological mechanism of increased excitation and reward that reinforce gambling. In the studies presented here, performance on simulated gambling tasks that provided varying levels gambling participation were compared to physiological measures of behavioral activation in problem gambler and nongamblers. Participants watched video clips of three horseraces scenarios that permitted different degrees of participation and control over wagering. Concurrently saliva samples …

Biological Motion Processing In Typical Development And In The Autism Spectrum, Aaron Krakowski

Dissertations, Theses, and Capstone Projects

Biological motion (BM) analysis and interpretation is a fundamental process of human neurocognition that has been only minimally explored neurophysiologically. In addition to its importance in understanding the underlying roots and development of social cognition, BM processing is a prime candidate domain for exploring the underlying etiology of social cognitive disorders such as the autism spectrum.

In an initial experiment, typical adults observed BM point-light displays of a human actor (UM) as well as their spatially scrambled counterparts (SM), in both an unattended distractor task as well as an explicit attention task. Results showed a neurophysiological response manifested as three …

The Effects Of Environmental Enrichment On Abstinence And Relapse Using An Animal Conflict Model, Joshua Alan Peck

Dissertations, Theses, and Capstone Projects

Heroin addiction is a significant health and societal problem for which there is no effective and well-accepted long-term behavioral or pharmacological treatment. Therefore, strategies that prolong heroin abstinence should be the primary focus of heroin treatment research. There is promising evidence that environmental enrichment may indeed support drug abstinence in animals using the reinstatement model of abstinence and relapse. The current studies used an animal conflict model that captures the aversive consequences of drug seeking (as are typical in humans, e.g., arrest, incarceration, job loss, and strained social relationships) to test the effects of environmental enrichment on heroin abstinence, prolonged …

Behavioral And Neuroanatomical Abnormalities In Pleiotrophin Knockout Mice, Jason W. Krellman, Henry H. Ruiz, Veronica A. Marciano, Bracha Mondrow, Susan D. Croll

Publications and Research

Pleiotrophin (PTN) is an extracellular matrix-associated protein with neurotrophic and neuroprotective effects that is involved in a variety of neurodevelopmental processes. Data regarding the cognitive-behavioral and neuroanatomical phenotype of pleiotrophin knockout (KO) mice is limited. The purpose of this study was to more fully characterize this phenotype, with emphasis on the domains of learning and memory, cognitive-behavioral flexibility, exploratory behavior and anxiety, social behavior, and the neuronal and vascular microstructure of the lateral entorhinal cortex (EC). PTN KOs exhibited cognitive rigidity, heightened anxiety, behavioral reticence in novel contexts and novel social interactions suggestive of neophobia, and lamina-specific decreases in neuronal …

Supraspinal And Spinal Mechanisms Of Morphine-Induced Hyperalgesia, Caroline A. Arout

Dissertations, Theses, and Capstone Projects

Morphine is the most prominent pharmacological treatment for moderate to severe pain in both acute and chronic paradigms. However, morphine notoriously elicits a paradoxical state of increased pain sensitivity known as hyperalgesia that complicates its use in clinical application. Research over the past three decades has reported that morphine-induced hyperalgesia is dose- and sex-dependent, and likely involves the synchronous activity of several neural networks beyond the opioid system. Whereas systemic, supraspinal, and spinal administration of morphine all cause hyperalgesia that is differentially reversible by N-methyl-D-aspartate receptor (NMDAR) antagonists or melanocortin-1 receptor (MC1R) antagonists, it is unknown as to whether or …

Quantitative Evaluation Of Microglial Activation And Vascularization In Suicide, Tatiana Pavlovna Schnieder

Dissertations, Theses, and Capstone Projects

Accumulated evidence points to immunological factors in psychiatric disorders. In a variety of chronic neurological disorders, exacerbation is associated with inflammation and a loss of integrity of the blood-brain barrier. Microglia, the principal brain immunological cells in the healthy state, respond to changes in the internal environment of the brain through a sequence of activated states. This study compared microglial phenotypes in the white matter of autopsy brains from 11 suicide victims and 25 subjects who died involuntarily. Both groups included cases with and without major psychiatric disorders, which were determined by PA interviews. Cases were matched for sex, age, …

Explorations Of Object And Location Memory Using Fmri, Andrew D. Passaro, L. Caitlin Elmore, Timothy M. Ellmore, Kenneth J. Leising, Andrew C. Papanicolaou, Anthony A. Wright

Publications and Research

Content-specific sub-systems of visual working memory (VWM) have been explored in many neuroimaging studies with inconsistent findings and procedures across experiments. The present study employed functional magnetic resonance imaging (fMRI) and a change detection task using a high number of trials and matched stimulus displays across object and location change (what vs. where) conditions. Furthermore, individual task periods were studied independently across conditions to identify differences corresponding to each task period. Importantly, this combination of task controls has not previously been described in the fMRI literature. Composite results revealed differential frontoparietal activation during each task period. A separation of object …

Sex-Specific Brain Deficits In Auditory Processing In An Animal Model Of Cocaine-Related Schizophrenic Disorders, Patricia A. Broderick, Taylor Rosenbaum

Publications and Research

Cocaine is a psychostimulant in the pharmacological class of drugs called Local Anesthetics. Interestingly, cocaine is the only drug in this class that has a chemical formula comprised of a tropane ring and is, moreover, addictive. The correlation between tropane and addiction is well-studied. Another well-studied correlation is that between psychosis induced by cocaine and that psychosis endogenously present in the schizophrenic patient. Indeed, both of these psychoses exhibit much the same behavioral as well as neurochemical properties across species. Therefore, in order to study the link between schizophrenia and cocaine addiction, we used a behavioral paradigm called Acoustic Startle. …

Serotonin 1a Receptor-Mediated Signaling Through Erk And Pkcα Is Essential For Normal Synaptogenesis In Neonatal Mouse Hippocampus, A. Mogha, Sara R. Guariglia, Priya Ranjan Debata, Guang Y. Wen, Probal Banerjee

Publications and Research

Aberrant expression of the presynaptic serotonin 1A receptor (5-HT_1A-R) because of a polymorphism in the 5-HT_1A-R gene is associated with severe depression in human, whereas its absence up to postnatal day 21 (P21) in the forebrain of mice results in heightened anxiety in adulthood. These observations collectively indicate that the 5-HT1A-R has a crucial role in brain development. To understand the mechanistic underpinnings of this phenomenon, we used organotypic slice cultures of hippocampi from C57BL6 mice (C57) at P15, which coincides with the peak of neonatal synaptogenesis. Stimulation of the hippocampal 5-HT1A-R caused a dramatic increase …

Insightful Problem Solving In An Asian Elephant, Preston Foerder, Marie Galloway, Tony Barthel, Donald E. Moore Iii, Diana Reiss

Publications and Research

The ‘‘aha’’ moment or the sudden arrival of the solution to a problem is a common human experience. Spontaneous problem solving without evident trial and error behavior in humans and other animals has been referred to as insight. Surprisingly, elephants, thought to be highly intelligent, have failed to exhibit insightful problem solving in previous cognitive studies. We tested whether three Asian elephants (Elephas maximus) would use sticks or other objects to obtain food items placed out-of-reach and overhead. Without prior trial and error behavior, a 7-year-old male Asian elephant showed spontaneous problem solving by moving a large plastic cube, on …

To See Or Not To See: Prestimulus Α Phase Predicts Visual Awareness, Kyle E. Mathewson, Gabriele Gratton, Monica Fabiani, Diane M. Beck, Tony Ro

Publications and Research

We often fail to see something that at other times is readily detectable. Because the visual stimulus itself is unchanged, this variability in conscious awareness is likely related to changes in the brain. Here we show that the phase of EEG α rhythm measured over posterior brain regions can reliably predict both subsequent visual detection and stimulus-elicited cortical activation levels in a metacontrast masking paradigm. When a visual target presentation coincides with the trough of an α wave, cortical activation is suppressed as early as 100 ms after stimulus onset, and observers are less likely to detect the target. Thus, …

Neural Substrates Of Sound–Touch Synesthesia After A Thalamic Lesion, Michael S. Beauchamp, Tony Ro

Publications and Research

Neural plasticity induced by stroke can mediate positive outcomes, such as recovery of function, but can also result in the formation of abnormal connections with negative consequences for perception and cognition. In three experiments using blood-oxygen level dependent (BOLD) functional magnetic resonance imaging, we examined the neural substrates of acquired auditory-tactile synesthesia, in which certain sounds can produce an intense somatosensory tingling sensation in a patient with a thalamic lesion. Compared with nine normal controls, the first experiment showed that the patient had a threefold greater BOLD response to sounds in the parietal operculum, the location of secondary somatosensory cortex. …

Mechanism Of Triazolo-Benzodiazepine And Benzodiazepine Action In Anxiety And Depression: Behavioral Studies With Concomitant In Vivo Ca1 Hippocampal Norepinephrine And Serotonin Release Detection In The Behaving Animal, Patricia A. Broderick, Omotola Hope, Pierrot Jeannot

Publications and Research

1. Real time, in vivo microvoltammetric studies were performed, using miniature carbon-based sensors, to concurrently detect norepinephrine (NE) release and serotonin (5-HT) release, in 2 separate electrochemical signals, within CA₁ region of hippocampus in the freely moving and behaving, male, Sprague Dawley laboratory rat.

2. Concurrently, four parameters of open-field Behavior I.E. Ambulations, Rearing, Fine Movements and Central Ambulatory behavior (a measure of anxiety reduction behavior), were assayed by infrared photobeam detection.

3. Time course studies showed that the mechanism of action of the triazolobenzodiazepine (TBZD), adinazolam, (Deracyn®) is dramatically different from that of the classical benzodiazepine (BZD), diazepam …