Behavioral Neurobiology Commons^™

Glutamate, And Its Relationship To Task-Induced Functional Connectivity In The Human Brain: A Focus On Schizophrenia, Kathleen Liu Young, John Kopchick, Jeffrey Stanley, Vaibhav Diwadkar

Medical Student Research Symposium

Glutamate is the brain’s major excitatory neurotransmitter mediating both neuroplasticity and network function (Zhou & Danbolt, 2014). Basal glutamate (Glu) measured using proton magnetic resonance spectroscopy (1H-MRS) provides insight into a region’s density of neuropil related to the glutamatergic system. Moreover, given the role of glutamate in mediating brain network function, Glu levels may play a role in the brain’s functional connectivity (FC), which is typically estimated from functional magnetic resonance imaging (fMRI) time series data. These questions converge when considering the clinical syndrome of schizophrenia (SCZ). Patients with SCZ show abnormalities in basal Glu in the hippocampus and prefrontal …

Artificial Light At Night Disrupts Pain Behavior And Cerebrovascular Structure In Mice, Jacob Raymond Bumgarner

Graduate Theses, Dissertations, and Problem Reports

Artificial Light at Night Disrupts Pain Behavior and Cerebrovascular Structure in Mice

Jacob R. Bumgarner

Circadian rhythms are intrinsic biological processes that fluctuate in function with a period of approximately 24 hours. These rhythms are precisely synchronized to the 24- hour day of the Earth by external rhythmic signaling cues. Solar light-dark cycles are the most potent environmental signaling cue for terrestrial organisms to align internal rhythms with the external day. Proper alignment and synchrony of internal circadian rhythms with external environmental rhythms are essential for health and optimal biological function.

The modern human environment on Earth is no longer …

Spatial Representation In Postrhinal Cortex, Patrick Lachance

Dartmouth College Ph.D Dissertations

Animals rely on a variety of internal and external cues to orient themselves when navigating their environments and determining their current spatial context. Information regarding these cues enters the brain from the navigator’s first-person perspective. Information of this type is considered to be egocentric, or self-centered. However, decades of behavioral, electrophysiological, and imaging research suggest that the brain contains a rich collection of spatial representations that are unrestricted by the animal’s first-person perspective, and instead are defined relative to the surrounding environment. These representations are considered allocentric, or world-centered. Despite an abundance of promising modeling work, the specific mechanisms by …

Mirnas Levels In A Streptozocin Model Of Alzheimer’S Disease, Nada Moustafa

Theses and Dissertations

Dementia entails a progressive decrease in cognitive functions, with 50%-75% of cases attributed to Alzheimer’s disease (AD); an aging-associated condition characterized by the build-up of tangled phosphorylated Tau (p-Tau) protein and beta-amyloid (Aβ) depositions. Sporadic AD (sAD) is multifactorial in nature, resulting from a combination of environmental and genetic predisposing factors. Type 2 diabetes mellitus (T2DM) is a leading risk factor for dementia, and deregulation of brain glucose metabolism is associated with early cognitive affection in sAD. Thus, the diabetogenic agent Streptozotocin (STZ) is used to experimentally create an AD model in animals (STZ-induced sAD), in which abnormalities in cerebral …

Withdrawal From Voluntary Oral Methamphetamine Reveals Female Specific Susceptibilities To Behavioral Deficits And Neurochemical Perpetuators Of Neurotoxicity And Drug Seeking Behavior, Nicoletta K. Memos

Dissertations, Theses, and Capstone Projects

MA is a potent, highly addictive psychomotor stimulant known to produce neurotoxic effects on the brain leading to neurological impairments^1-6 characterized by neurodegeneration of dopaminergic fibers, cell bodies and pathways, as well as brain regions such as the hippocampus, frontal cortex, and midbrain^1,5.

In MA addiction, women are more vulnerable to the behavioral and cognitive effects of MA compared to men. Adult human literature reveals gender differences in usage patterns and women demonstrate increased vulnerability to the neurotoxic effects and health effects of MA use. Women begin drug use at an earlier age, escalate drug use quicker, …

The Effects Of Astrocytic Derived Insulin-Like Growth Factor (Igf-1) On Cognition And Astrocytes, Destiny Wilson

Honors Theses

Insulin-like growth factor 1 (IGF-1) is a neuroendocrine signaling hormone that plays a vital role in growth and development, as well as learning and memory. Inhibition of this hormone results in cognitive impairments like those seen with age-related decline. While a majority of research has focused on the role of IGF-1 on neurons, the role of astrocytes still needs to be explored. Our research investigates how astrocytes and cognition are affected as a result of direct regulation of localized IGF-1 production in early development and after puberty. Preliminary studies in our laboratory established a connection between IGF-1 and glial fibrillary …

Case Study: Effects Of Ultrasonic Vocalizations On Rat Behavior And Place Cell Remapping In The Hippocampus, Qingli Hu

Honors Scholar Theses

Spatial information is known to be encoded in the hippocampus, and small changes in the environment can alter the way that it is represented by our hippocampal place cells in a process called remapping. Hearing is an important sense that can be used to orient ourselves and react to the environment accordingly. In this case study, a rat model is used to test the effects of emotional auditory stimuli, behaviorally significant ultrasonic vocalizations (USVs) (50 kHz, emitted during play; 22 kHz, emitted during danger), on rat behavior on a linear track and place cell remapping in the hippocampus. Behaviorally, it …

Targeting Ampa Receptor Modulation During Early Life Adversity: A Mediator For Threat Associated Memories, Roseanna M. Zanca

Dissertations, Theses, and Capstone Projects

Early life adversity (ELA) is the exposure to a single or to multiple traumatic events before the age of 18 that go beyond the child’s coping. These adverse events are often exacerbated during adolescence particularly when cognitive performance is compromised. Adolescents who experienced ELA may show symptoms of post-traumatic stress disorder (PTSD), while not vividly recalling the early life trauma. These individuals show atypical connectivity between prefrontal-amygdala and hippocampus, all of which is associated with an increased risk of experiencing a traumatic event again later in life. While clinical research has increasingly stressed the importance in addressing the long-lasting consequences …

The Neurobiological Relationship Between Childhood Maltreatment And Major Depressive Disorder (Mdd), Morgan Clinton

Global Tides

Childhood maltreatment compromises healthy development, impacts neurobiology, and is associated with lasting alterations to emotional perception, processing, and regulation. Most significantly, childhood maltreatment increases the risk for later development of emotional disorders such as major depressive disorder (MDD). The stress associated with both childhood maltreatment and MDD can lead to lasting alterations to the fronto-limbic circuitry. Using functional and structural magnetic resonance imaging, researchers have observed hippocampal atrophy and amygdala hyperresponsiveness in participants who’ve experienced both childhood maltreatment and MDD. Furthermore, researchers have also observed increased connectivity between the hippocampus and amygdala in victims of childhood maltreatment. Because childhood maltreatment …

Wild Mice With Different Social Network Sizes Vary In Brain Gene Expression, Patricia C. Lopes, Barbara König

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background

Appropriate social interactions influence animal fitness by impacting several processes, such as mating, territory defense, and offspring care. Many studies shedding light on the neurobiological underpinnings of social behavior have focused on nonapeptides (vasopressin, oxytocin, and homologues) and on sexual or parent-offspring interactions. Furthermore, animals have been studied under artificial laboratory conditions, where the consequences of behavioral responses may not be as critical as when expressed under natural environments, therefore obscuring certain physiological responses. We used automated recording of social interactions of wild house mice outside of the breeding season to detect individuals at both tails of a distribution …

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. …

Exploring The Role Of Insulin Receptor Signaling In Hippocampal Learning And Memory, Neuronal Calcium Dysregulation, And Glucose Metabolism, Hilaree N. Frazier

Theses and Dissertations--Pharmacology and Nutritional Sciences

In the late 90’s, emerging evidence revealed that the brain is insulin-sensitive, highlighted by broad expression of brain-specific insulin receptors and reports of circulating brain insulin. Contemporary literature robustly supports the role of insulin signaling in normal brain function and suggests that insulin-related processes diminish with aging, evidenced by decreased signaling markers, reduced insulin receptor density, and lower levels of insulin transport across the blood-brain barrier. In the context of pathological cognitive decline, clinical trials using intranasal insulin delivery have reported positive outcomes on memory and learning in patients with mild cognitive decline or early-stage Alzheimer’s disease. However, while the …

Contextual Fear Memory Modulates Psd95 Phosphorylation, Ampar Subunits, Pkmζ And Pi3k Differentially Between Adult And Juvenile Rats, Roseanna M. Zanca, Shirley Sanay, Jorge A. Avila, Edgar Rodriguez, Harry N. Shair, Peter A. Serrano

Publications and Research

It is well known that young organisms do not maintain memories as long as adults, but the mechanisms for this ontogenetic difference are undetermined. Previous work has revealed that the α-amino-3-hydroxy-5-methyl-4isoxazolepropionic acidreceptor (AMPAr)subunits aretraffickedinto the synaptic membranefollowing memory retrieval in adults. Additionally, phosphorylated PSD-95-pS295 promotes AMPAr stabilization at the synapse. We investigated these plasticity related proteins as potential mediators in the differential contextual stress memory retrieval capabilities observed between adult and juvenile rats. Rats were assigned to either pedestal stress (1h) or no stress control (home cage). Each animal was placed alone in an open field for 5minat the base …

Defining The Radioresponse Of Mossy Cells, Devon Ivy

Electronic Theses, Projects, and Dissertations

Clinical radiotherapy is used to treat a variety of brain tumors within the central nervous system. While effective, it can result in progressive and debilitating cognitive impairment that can diminish quality of life. These impairments have been linked to hippocampal dysfunction and corresponding deficits in spatial learning and memory. Mossy cells are a major population of excitatory neurons located within the dentate hilus and highly involved in hippocampal circuitry. They play critical roles in spatial navigation, neurogenesis, memory, and are particularly vulnerable to a variety of neurotoxic insults. However, their sensitivity to ionizing radiation has yet to be investigated in …

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 …

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) …

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 …

Are There Place Cells In The Avian Hippocampus?, David F Sherry, Stephanie L Grella, Mélanie F Guigueno, David J White, Diano F Marrone

Psychology Publications

Birds possess a hippocampus that serves many of the same spatial and mnemonic functions as the mammalian hippocampus but achieves these outcomes with a dramatically different neuroanatomical organization. The properties of spatially responsive neurons in birds and mammals are also different. Much of the contemporary interest in the role of the mammalian hippocampus in spatial representation dates to the discovery of place cells in the rat hippocampus. Since that time, cells that respond to head direction and cells that encode a grid-like representation of space have been described in the rat brain. Research with homing pigeons has discovered hippocampal cells, …

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.

Histological Verification Of Electrode Placement In Single Unit Recorded Rats, Dana Lew

Honors Scholar Theses

The hippocampus is a region of the brain which plays a major role in encoding spatial and episodic memory. The hippocampus is divided in to two main subregions, dorsal and ventral. These subregions are connected, but their functional organization remains widely unknown. Place cells are cells of the hippocampus which fire in a specific spatial area and help create a mental map of our surroundings. Place cells have been seen to remain constant during slight fluctuations in surroundings, but completely remap in response to large fluctuations in the environment. There is little known about the relatively few place cells in …

Spike Field Coherence (Sfc) For Ripples In Rat Hippocampus, Pranav Singla

Honors Scholar Theses

The aim of this project was to determine coherence between two types of neural recordings which can be obtained from the rat hippocampus: spikes and local field potentials. Extracellular recording makes it possible to determine spiking activity from individual neurons in the vicinity of the recording electrode. Local field potential recording gives a combined activity of many neurons (thousands) at once to determine an overall picture of the coordination of the cells in real time. Here we examine the relationship between these two signals, focusing on place cells which spike at their maximal rate only at certain positions in physical …

Abnormal Hippocampal Activation In Freely Behaving Mice Deficient For The Vesicular Acetylcholine Transporter, Shahin Moallem

Electronic Thesis and Dissertation Repository

Acetylcholine (Ach) has a fundamental role in cortical activation. The activation of the hippocampus, a cortex implicated in cognitive and sensorimotor functions, is characterized by an increase in power and frequency of oscillations in the theta (4-10 Hz) and gamma (30-100 Hz) frequency range. We studied hippocampal activation in two mutant mouse lines with deficiency in cholinergic functionality: VAChT KD^HET (HET), and VAChT^{Nkx2.1-Cre-flox/flox} (KO). We hypothesized that the mutant mice, relative to wild-type (WT) mice, will manifest abnormal theta and gamma oscillations during different behaviors, and in response to muscarinic cholinergic antagonist scopolamine hydrochloride and to the NMDA …

Synaptic And Systems Memory Consolidation In The Black-Capped Chickadee (Poecile Atricapillus), Matthew Barrett

Matthew J. Barrett

ABSTRACT Memory consolidation - the time-dependent stabilization of information- involves two processes: 1) synaptic consolidation and 2) systems consolidation. Synaptic consolidation uses a series of protein synthesis cascades that make lasting changes in the underlying neural architecture of a memory. Systems consolidation involves the reorganization of memory such that, with the passage of time, memory that is initially hippocampus-dependent can be retrieved and activated independent of the hippocampus. Black-capped chickadees (Poecile atricapillus) store and relocate food using hippocampus-dependent spatial memory. In Chapter 2 inhibition of protein synthesis by anisomycin, either 0 and 2 h or 4 and 6 h after …

Loss Of Dendritic Inhibition In The Hippocampus After Repeated Early-Life Hyperthermic Seizures In Rats., Richard Boyce, L Stan Leung

Physiology and Pharmacology Publications

Seizures are relatively common in children and are a risk factor for subsequent temporal lobe epilepsy. To investigate whether early-life seizures themselves are detrimental to the proper function of the adult brain, we studied whether dendritic excitation and inhibition in the hippocampus of adult rats were altered after hyperthermia-induced seizures in immature rats. In particular, we hypothesized that apical dendritic inhibition in hippocampal CA1 pyramidal cells would be disrupted following hyperthermia-induced seizures in early life. Seizure rats were given three hyperthermia-induced seizures per day for three days from postnatal day (PND) 13 to 15; control rats were handled similarly but …

Septohippocampal Gabaergic Neurons Mediate The Altered Behaviors Induced By N-Methyl-D-Aspartate Receptor Antagonists., Jingyi Ma, Siew Kian Tai, L Stan Leung

Physiology and Pharmacology Publications

We hypothesize that selective lesion of the septohippocampal GABAergic neurons suppresses the altered behaviors induced by an N-methyl-D-aspartate (NMDA) receptor antagonist, ketamine or MK-801. In addition, we hypothesize that septohippocampal GABAergic neurons generate an atropine-resistant theta rhythm that coexists with an atropine-sensitive theta rhythm in the hippocampus. Infusion of orexin-saporin (ore-SAP) into the medial septal area decreased parvalbumin-immunoreactive (GABAergic) neurons by ~80%, without significantly affecting choline-acetyltransferase-immunoreactive (cholinergic) neurons. The theta rhythm during walking, or the immobility-associated theta induced by pilocarpine, was not different between ore-SAP and sham-lesion rats. Walking theta was, however, more disrupted by atropine sulfate in ore-SAP than …

Synaptic And Systems Memory Consolidation In The Black-Capped Chickadee (Poecile Atricapillus), Matthew Barrett

Electronic Thesis and Dissertation Repository

ABSTRACT

Memory consolidation - the time-dependent stabilization of information- involves two processes: 1) synaptic consolidation and 2) systems consolidation. Synaptic consolidation uses a series of protein synthesis cascades that make lasting changes in the underlying neural architecture of a memory. Systems consolidation involves the reorganization of memory such that, with the passage of time, memory that is initially hippocampus-dependent can be retrieved and activated independent of the hippocampus. Black-capped chickadees (Poecile atricapillus) store and relocate food using hippocampus-dependent spatial memory. In Chapter 2 inhibition of protein synthesis by anisomycin, either 0 and 2 h or 4 and 6 …

Seasonal Hippocampal Plasticity In Food-Storing Birds., David F Sherry, Jennifer S Hoshooley

Psychology Publications

Both food-storing behaviour and the hippocampus change annually in food-storing birds. Food storing increases substantially in autumn and winter in chickadees and tits, jays and nutcrackers and nuthatches. The total size of the chickadee hippocampus increases in autumn and winter as does the rate of hippocampal neurogenesis. The hippocampus is necessary for accurate cache retrieval in food-storing birds and is much larger in food-storing birds than in non-storing passerines. It therefore seems probable that seasonal change in caching and seasonal change in the hippocampus are causally related. The peak in recruitment of new neurons into the hippocampus occurs before birds …

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 …