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Articles 1 - 30 of 31
Full-Text Articles in Neurosciences
Advancing Research On Retinitis Pigmentosa: An Investigation Of Natural History, Visual System Plasticity, And Mutation-Independent Treatment., Cecilia A. Attaway
Advancing Research On Retinitis Pigmentosa: An Investigation Of Natural History, Visual System Plasticity, And Mutation-Independent Treatment., Cecilia A. Attaway
Electronic Theses and Dissertations
Retinitis Pigmentosa (RP) is an inherited retinal disease characterized by rod and then cone photoreceptor degeneration. ~25% of cases are caused by a genetic mutation that results in autosomal dominant RP (adRP). There has been a lack of exploration of the progression of degeneration in adRP models. In Chapter Two, I examined visual acuity (VA) changes, retinal structure, and function from early to late-stage disease in a murine P23H Rho ‘knock-in’ mouse model (RhoP23H/+), the most common form of adRP in North America. To establish a natural history, I evaluated behavioral VA, using the visual water task, …
Regulation And Mechanisms Of Ocular Dominance Plasticity At Cellular Resolution., Thomas Christopher Brown
Regulation And Mechanisms Of Ocular Dominance Plasticity At Cellular Resolution., Thomas Christopher Brown
Electronic Theses and Dissertations
Sensory systems throughout the brain require experience to aid in proper wiring during development. While forming, many sensory systems have periods of heightened sensitivity where alterations in the quality of experience can have a profound impact on cortical responses throughout life. These periods of heightened sensitivity have been coined critical periods. In the visual system of mice a critical period for ocular dominance has been well studied and defined between postnatal days nineteen and thirty-six. During this critical period, altering visual experience by suturing one eye closed called monocular deprivation (MD) shifts responses in cortex towards the non-deprived eye. Similar …
Epidural Stimulation For Urogenital Dysfunction In The Spinal Cord Injured Rat., Natasha Lorraine Wilkins
Epidural Stimulation For Urogenital Dysfunction In The Spinal Cord Injured Rat., Natasha Lorraine Wilkins
Electronic Theses and Dissertations
Spinal cord injury (SCI) is a devastating, life changing event that greatly impacts quality of life. SCI can have body-wide, multi-system consequences including dysfunction within the urogenital system. Challenges with the urinary system include urinary incontinence, urine retention, and detrusor-sphincter dyssynergia all of which require maintenance through the regular use of catheters. Sexual dysfunction in men, who comprise nearly 80% of the SCI population, includes erectile dysfunction, anejaculation, retrograde ejaculation, poor expulsive force during ejaculation, and poor sperm quality. The treatment for sexual function in SCI men is focused more on fertility through the collection of sperm for insemination procedures …
Cannabis Exposure During Pregnancy And Neural Mechanisms Of Parenting: Assessing Neural Responses To Infant Cues And Parenting Outcomes, Shannon Powers
Cannabis Exposure During Pregnancy And Neural Mechanisms Of Parenting: Assessing Neural Responses To Infant Cues And Parenting Outcomes, Shannon Powers
Electronic Theses and Dissertations
As legalization of cannabis and cannabinoids spreads in the United States, access and use of cannabis during the prenatal period has increased. There is limited knowledge on the effects of prenatal cannabis use on the parental brain. One way to identify potential effects of cannabis on parenting is through studying parenting brain functions and behavior. Cannabis use disorder (CUD) has been shown to be associated with lower positive parenting and lower sensitivity to infants, but it is unclear by what mechanisms. The following two studies address this gap in knowledge by examining the association between cannabis use during the prenatal …
Validation Of A Novel Heritable Rodent Model Of Drug Abuse Vulnerability In Psychosis And Investigation Of Therapeutic Targets, Loren D. Peeters
Validation Of A Novel Heritable Rodent Model Of Drug Abuse Vulnerability In Psychosis And Investigation Of Therapeutic Targets, Loren D. Peeters
Electronic Theses and Dissertations
Schizophrenia is a severe neuropsychiatric disorder of largely unknown etiology that is often accompanied by high rates of cigarette smoking, reduced quit success, and high relapse rates. Dysregulated dopamine signaling and aberrant synaptic plasticity in the mesocorticolimbic pathway are implicated in the pathophysiology of schizophrenia and conferred substance abuse disorder and relapse vulnerability. Genetic factors are presumed to play a significant role in the development of schizophrenia, with a 40-50% concordance rate for monozygotic twins, although genetic markers are inconsistent. As such, epigenetic factors have instead been implicated. Specifically, there is strong evidence to suggest DNA methylation at several candidate …
Perinatal Buprenorphine Effects On Offspring Growth, Opioid Withdrawal, And Brain Morphology In Rats, Parker Barnes
Perinatal Buprenorphine Effects On Offspring Growth, Opioid Withdrawal, And Brain Morphology In Rats, Parker Barnes
Electronic Theses and Dissertations
Opioid use disorder (OUD) impacts 5.6 million people in the US. Buprenorphine (BUP) is a commonly prescribed opioid medication used to treat OUD, including in pregnant women. However, opioid use during pregnancy is associated with poorer infant outcomes including reduced fetal growth, neurodevelopmental deficits, and neonatal opioid withdrawal syndrome (NOWS). Recent clinical data suggests that providing mothers with a lower dose of BUP may result in fewer negative outcomes in infants. Here, a preclinical rodent model of low-dose perinatal BUP exposure was used to study offspring health outcomes in the neonate, juvenile, and adolescent offspring. Dams were given clinically relevant …
Control Of Muscle Activation In The Lower Limbs During Leg Cycling After A Motor Complete Spinal Cord Injury., Jae Fish
Electronic Theses and Dissertations
Spinal cord injury (SCI) affects the central nervous system (CNS) causing muscle paralysis and autonomic dysfunctions throughout the body. Muscle activation after SCI is essential to facilitate functional recovery and may be produced via remaining input from supraspinal centers, the central pattern generators (CPG), or muscle stretch reflex responses. In this study, assisted leg cycling is evaluated as a tool to identify the neural structure control of muscle activation after motor complete SCI. Eight individuals with a complete or sensory incomplete SCI between C2 and T5 participated in the study. Participants completed leg cycling trials with and without supraspinal intention …
Optimization Of Vagus Nerve Stimulation (Vns) And The Use Of Cervical Vns As A Treatment For Heart Failure With Reduced Ejection Fraction, Misty Owens
Electronic Theses and Dissertations
Vagus nerve stimulation (VNS) is a promising neuromodulatory therapy under investigation for a range of disorders, including heart failure, gastric dysmotility, and migraine. Two primary forms of VNS are currently investigated: cervical VNS (cVNS), involving surgically implantation to activate vagal afferents in the cervical branch in the neck and transcutaneous auricular VNS (taVNS) which subcutaneously stimulates the auricular branch in the outer ear. The nucleus of the solitary tract (NTS) serves as a relay-station receiving 90% of vagal afferents, enabling connections with higher-order brain regions and other brainstem nuclei like the spinal trigeminal nucleus (Sp5) and locus coeruleus (LC), facilitating …
Injury Induced Neuroplasticity And Cell Specific Targeting Of The Lumbar Enlargement For Gene Therapy., Brandon Lee Brown
Injury Induced Neuroplasticity And Cell Specific Targeting Of The Lumbar Enlargement For Gene Therapy., Brandon Lee Brown
Electronic Theses and Dissertations
This dissertation is an examination of spinal cord injury induced neuroplasticity and tests whether noninvasive gene therapy can successfully target neurons in the lumbar spinal cord. It begins with an overview of neural control of locomotion and a brief summary of therapeutics that are used and/or in development for treating spinal anatomically characterize s subset of neurons in the spinal cord, long ascending propriospinal neurons, that are involved in interlimb coordination. Characterization of these neurons allows for subsequent evaluation of their potential involvement in injury induced neuroplasticity. This dissertation is divided into five chapters, covering spinal cord injury and therapeutics. …
On-Campus Mental Health Service Use Among College Students With Autism: A Case Study Applying The Andersen Behavioral Model Of Health Services Use, Estella C. Lilyquist
On-Campus Mental Health Service Use Among College Students With Autism: A Case Study Applying The Andersen Behavioral Model Of Health Services Use, Estella C. Lilyquist
Electronic Theses and Dissertations
The unique set of impairments and limitations presented by students with autism spectrum disorder (ASD) make the accessing of campus-based nonacademic resources more difficult and complicated than their typically developed peers. Each year, the rate of students entering college with disabilities continues to grow, but their mental well-being is relatively poor. The purpose of this qualitative case study was to apply the conceptual framework of the Andersen behavioral model of health services use (ABMHSU) to the experiences of college students with ASD to understand and predict their utilization of campus-provided mental health resources. The participants were seven college students with …
Toward A Comprehensive Account Of Orientation Selectivity In The Retina., Megan Zipperer
Toward A Comprehensive Account Of Orientation Selectivity In The Retina., Megan Zipperer
Electronic Theses and Dissertations
Retinal Ganglion Cells (RGCs) form functionally distinct signaling channels that selectively encode features of the visual input including direction of motion, contrast polarity, size, and color. A highly conserved visual channel amongst vertebrates conveys orientation selectivity, i.e., the selective firing of neuronal cells in response to elongated stimuli along a preferred orientation. Orientation selectivity is an apparent critical computation and several studies have reported aspects of it, including cell type identity in anatomical reconstructions, and functional characterization of at least four different identified RGC types. But how cell types in the different studies relate is not well resolved; the mechanisms …
An Analysis Of Taste Neuron Morphological Variability: Influences Of Neuron Type And Plasticity., Lisa Christina Ohman
An Analysis Of Taste Neuron Morphological Variability: Influences Of Neuron Type And Plasticity., Lisa Christina Ohman
Electronic Theses and Dissertations
Taste neurons are functionally and molecularly diverse, but their morphological diversity was, until recently, completely unexplored. Taste neurons were considered relay cells, communicating information from taste-transducing cells to the brain without variation in morphology. Instead, individual taste neurons are tremendously morphologically variable. To determine how differences in branching relate to the number and types of taste-transducing cells providing neuronal input, I combined sparse cell genetic labeling with a whole-mount immunohistochemistry and analysis workflow. I found that the maximum number of taste-transducing cells capable of providing convergent input onto individual gustatory neurons varied with a range of 1-22 taste-transducing cells. Consistently, …
Effects Of Chemosensory Experience And Context On Consummatory Behaviors., Saphira M. Chiu
Effects Of Chemosensory Experience And Context On Consummatory Behaviors., Saphira M. Chiu
Electronic Theses and Dissertations
Eating food generates associations between odors and tastes (i.e., flavor) that guide future choices. Experience with an odor-taste mixture links an odor with a taste’s quality and hedonic value, resulting in a preference for an odor paired with a palatable taste over an odor paired with an unpalatable taste. However, experience with a neutral stimulus (i.e., latent inhibition) or environment (i.e., context) can influence the formation of conditioned associations. Here, I used a two-bottle brief-access task to determine whether rats display an innate preference between unpaired odors (isoamyl acetate and benzaldehyde), how preexposure to the unpaired odors impacts mixture-dependent consummatory …
Oligodendrocyte Responses After Spinal Cord Injury., George Zach Wei
Oligodendrocyte Responses After Spinal Cord Injury., George Zach Wei
Electronic Theses and Dissertations
Recent studies demonstrate that neuroprotection strategies targeting the proteostasis network and components of its effector signaling pathways improve cell survival and motor recovery outcomes in several models of neuronal injury and degeneration. However, the individual contributions of these signaling pathways to the pathogenesis of spinal cord injury (SCI), white matter damage, and motor recovery have not yet been determined. Here, I explored the role of the HIF prolyl hydroxylase domain proteins (PHD/EGLN), effectors that can modulate stress responses activated by the proteostasis network, on motor function recovery after SCI. Furthermore, I identified previously unknown candidate mechanisms in an unbiased manner …
Maternal Hpa Axis Function During Parenting Is Associated With Reduced Brain Activation To Infant Cry And More Intrusive Parenting Behavior, Andrew Erhart
Electronic Theses and Dissertations
Previous research indicated that maternal cortisol function and maternal brain response to infant stimuli are separately related to differences in parenting behavior. Evidence from animal models have demonstrated that chronically high cortisol concentration alters brain structure and function, suggesting that studying these two mechanisms together may further improve understanding of parental behavior in human mothers. First time mothers of infants aged 1-7 months old (M age = 3 months) were recruited to participate. Mother’s cortisol concentration was measured during a naturalistic interaction with their infant and their behavior was coded for maternal sensitivity and nonintrusiveness. In a separate session using …
The Role Of Acetylcholine In Attention And Lapses In Attention In Rats Using The Mode And Deviation From Mode Of Reaction Time Latency, Scott Lee Mitchell
The Role Of Acetylcholine In Attention And Lapses In Attention In Rats Using The Mode And Deviation From Mode Of Reaction Time Latency, Scott Lee Mitchell
Electronic Theses and Dissertations
Attention Deficit-Hyperactivity Disorder (ADHD) is currently the neurodevelopmental disorder most commonly diagnosed in children in the United States, and one of the defining characteristics of ADHD is inattention. Inattention is marked by increased lapses in attention, and when assessed clinically, it has been highly correlated with reaction-time variability (RTV). Evidence from the human/clinical literature has shown an inherently higher RTV to be the primary quantitative indicator of an ADHD diagnosis. Reaction-time distributions are characterized by an asymmetrical rightward skew, and because of the prevalence of this presentation, it has been theorized that the distribution peak and skew represent separate phenomena, …
Chronic Effects Of Methylphenidate On Neuronal Viability And Plasticity, Hannah Oakes
Chronic Effects Of Methylphenidate On Neuronal Viability And Plasticity, Hannah Oakes
Electronic Theses and Dissertations
Methylphenidate (MPH) is the most commonly prescribed drug to treat Attention Deficit Hyperactivity Disorder (ADHD). ADHD is now considered a life-long disorder; therefore, patients take MPH from adolescence into adulthood, highlighting the need for research studying chronic MPH use. MPH increases dopamine and norepinephrine within the synaptic cleft; therefore, chronic use of MPH may lead to changes within important dopaminergic pathways. One pathway, the mesolimbic pathway, includes the hippocampus, an area where adult neurogenesis occurs. We investigated the effects of chronic low and high doses of MPH on neurogenesis and examined levels of a few key proteins linked to cell …
Bdnf-Related Gene Expression Of Laser Capture Microdissected Glutamate Neurons From The Anterior Cingulate Cortex In Mouse Models Of Autism Spectrum Disorder, Misty Owens
Electronic Theses and Dissertations
Autism spectrum disorder (ASD) is a neurodevelopmental disorder affecting social behaviors. ASD affects 1 in 59 children with males affected more frequently. ASD is postulated to result from excitatory and inhibitory neurotransmission imbalances. Brain-derived neurotrophic factor (BDNF) signaling affects ASD by influencing synaptogenesis, plasticity, and survival. Studying early in-utero neuropathological changes within ASD requires the use of animal models. Expression of BDNF-associated genes were analyzed within laser capture microdissected pyramidal neurons from the anterior cingulate cortex of male and female BTBR and valproic acid mouse models. No expression differences were found in any gene comparing the three groups. Gender comparisons …
Behavioral And Neurobiological Evidence Of Epigenetic Transmission In The Neonatal Quinpirole Rodent Model Of Schizophrenia, Wesley Gill
Electronic Theses and Dissertations
Quinpirole is a dopamine D2 receptor agonist that if administered to rats from postnatal day (P)1-21 results in increased dopamine D2 receptor sensitivity throughout the animal’s lifetime. This increase in receptor sensitivity is consistent with schizophrenia. This model has additional consistencies with human schizophrenia, including sensorimotor gating deficits, enhanced behavioral and neurobiological responses to nicotine, and protein alterations consistent with the disorder. In this study, a second generation of the neonatal quinpirole (NQ) rodent model was created to investigate if long term changes caused by NQ treatment would be passed to offspring. NQ treated rats were mated and their offspring …
The Effect Of Spinal Cord Injury On Sexual Function., Casey J. Steadman
The Effect Of Spinal Cord Injury On Sexual Function., Casey J. Steadman
Electronic Theses and Dissertations
Spinal cord injury (SCI) causes severe neurological impairment with widespread motor, autonomic and sensory deficits, leading to a substantial quality of life impairment. The number of individuals with SCI increases by approximately 12,500 annually, and over 80% of individuals with SCI are males. SCI individuals rate sexual function as a top priority quality of life issue, and men with SCI likely suffer from sexual dysfunction, such as erectile and ejaculatory dysfunction, as well as infertility. Regardless of the high status of importance of sexual function, limited numbers of experimental studies in SCI animal models have focused on sexual function after …
Reward And Punishment: The Neural Correlates Of Reinforcement Feedback During Motor Learning, Christopher Mark Hill
Reward And Punishment: The Neural Correlates Of Reinforcement Feedback During Motor Learning, Christopher Mark Hill
Electronic Theses and Dissertations
‘By the carrot or the stick’ reward or punishment has been contemplated by instructors to motivate their pupils to learn a new motor skill. The reinforcements of reward and punishment have demonstrated dissociable effects on motor learning with punishment enhancing the learning rate and reward increasing retention of the motor task. However it is still unclear how the brain processes reward and punishment during motor learning. This study sought to investigate the role of reinforcement feedback in cortical neural activity associated with motor learning. A novel visuomotor rotation task was employed with reward punishment or null feedback as the participants …
The Migration And Developmental Remodeling Of Intrinsic Interneurons In Visual Thalamus And The Role Of Retinal Signaling., Naomi E. Charalambakis
The Migration And Developmental Remodeling Of Intrinsic Interneurons In Visual Thalamus And The Role Of Retinal Signaling., Naomi E. Charalambakis
Electronic Theses and Dissertations
The dorsal lateral geniculate nucleus (dLGN) of the mouse is a model system to study the development of thalamic circuitry. While most studies focus on relay neurons of dLGN, little is known about the factors regulating the development of the other principal cell type, intrinsic interneurons. To date, the targeting and migratory path of dLGN interneurons as well as their morphological development remains unclear. Here we examined whether the migration, structure, and function of interneurons relies on retinal signaling. We took a loss-of-function approach and crossed GAD67-GFP mice, which express green fluorescent protein (GFP) in dLGN interneurons, with math5 nulls …
On The Future Of Antidepressant Treatments: Targeting Neurotrophic Factors And Plasticity, Stephen W. White
On The Future Of Antidepressant Treatments: Targeting Neurotrophic Factors And Plasticity, Stephen W. White
Electronic Theses and Dissertations
For 60-plus years the explanatory model for Major Depressive Disorder (MDD) has been the monoamine theory, which states that low levels of monoamine neurotransmitters or alterations in their post-synaptic receptors are responsible for depressive symptoms. Drugs designed to elevate synaptic monoamine levels have remained the first line of pharmacotherapy prescribed by clinicians for MDD patients. However, these drugs have shortcomings. Despite evidence that current antidepressants elevate synaptic monoamine levels within hours of administration, these drugs require four to six weeks of daily administration before symptom relief appears. Furthermore, approximately half of patients taking typical antidepressants never achieve full symptom relief. …
Trunk And Respiratory Motor Control In Typically Developing Children And Its Implications In Children With Chronic Spinal Cord Injury., Goutam Singh
Electronic Theses and Dissertations
Independent sitting is a major milestone and is also a prerequisite for optimal performance of activities of daily living (ADLs). Development of sitting posture control is a dynamic process involving control of degrees of freedom of head and trunk. Traditionally, trunk has been modeled as a single unit (segment). However, recent studies have suggested that it is made up multiple spinal units, controlled by a combination of trunk muscles. During typical development, posture control of trunk is different for different trunk segments. This motor development of trunk control is a complex process due to constant interaction between the nervous system …
Implication Of Alpha-Synuclein Transcriptional Regulation And Mutagenesis In The Pathogenesis Of Sporadic Parkinson's Disease, Sambuddha Basu
Implication Of Alpha-Synuclein Transcriptional Regulation And Mutagenesis In The Pathogenesis Of Sporadic Parkinson's Disease, Sambuddha Basu
Electronic Theses and Dissertations
Parkinson's disease (PD) is an age-related neurodegenerative disorder characterized by selective loss of dopaminergic neurons (DA neurons) from the substantia nigra (SN) of the mid-brain. PD is classically associated with cytoplasmic inclusion of aggregated proteins called Lewy bodies. alpha-synuclein (α-SYN) coded by the gene SNCA, is one of the major components of Lewy body and neurite along with several other proteins like ubiquitin, neurofilament to name a few. PD is broadly categorized into two groups based on their incidence of occurrence. First is the familial form that occurs due to known genetic aberrations like mutation, gene duplication/triplication in important PD …
Evaluating Cardiovascular Dysfunction During Increased Activity And Exercise Rehabilitation Following Incomplete Thoracic Spinal Cord Injury In The Adult Rat., Kathryn A. Harman
Evaluating Cardiovascular Dysfunction During Increased Activity And Exercise Rehabilitation Following Incomplete Thoracic Spinal Cord Injury In The Adult Rat., Kathryn A. Harman
Electronic Theses and Dissertations
Spinal cord injury (SCI) results in whole-body dysfunction. While the majority of SCI research is focused on improving locomotor function after injury, cardiovascular (CV) disease continues to be the leading cause of morbidity in the chronic SCI patient population. The combination of injury-induced destruction of autonomic pathways, maladaptive plasticity within lumbosacral circuits, and the progressive decline in physical fitness contribute to the poor CV status of SCI individuals. Currently, there is little emphasis on implementing appropriately-timed acute rehabilitation techniques aimed to curtail maladaptive remodeling and improve CV outcomes. Furthermore, no pre-clinical or clinical studies have investigated the most appropriate time-course …
Cardiovascular Regulation And Effects Of Respiratory Motor Training In Patients With Chronic Spinal Cord Injury., Bonnie Legg Ditterline
Cardiovascular Regulation And Effects Of Respiratory Motor Training In Patients With Chronic Spinal Cord Injury., Bonnie Legg Ditterline
Electronic Theses and Dissertations
This dissertation attempts to discover the mechanisms between cardiovascular and respiratory motor control post spinal cord injury (SCI): in normal, non-injured (NI) persons, cardiovascular regulation is dependent upon respiration, but there is nothing that suggests the mechanism for this relationship post-SCI. Thus we hoped to evaluate various aspects of cardiovascular regulation to further illustrate how this relationship is changed or unchanged by SCI. Chapter I describes the anatomy and physiology of the spine, respiratory system, and cardiovascular system in a NI person, and then describes how the function of these systems is changed by SCI. In addition, we describe therapies …
Bdnf Maintains Adult Taste Innervation And Is Required For Taste Nerve Regeneration After Injury., Lingbin Meng
Bdnf Maintains Adult Taste Innervation And Is Required For Taste Nerve Regeneration After Injury., Lingbin Meng
Electronic Theses and Dissertations
Brain derived neurotropic factor (BDNF) is required for the gustatory neuron survival,target innervation, and taste bud maintenance during development. However, whether BDNF has any function in the adult gustatory system in normal conditions or after nerve injury is unclear. To address these issues, I inducibly removed BDNF in all cells expressing BDNF in adult mice. In the experimental animals, Bdnf expression decreased to 5% of control mice in the lingual epithelium and geniculate ganglion (p< 0.01) at both two weeks and ten weeks after tamoxifen administration. I found no effect on taste bud morphology at four weeks following Bdnf gene deletion. However, ten weeks following Bdnf gene deletion, P2X3-positive and TUJ1-positive gustatory innervation to individual taste buds was reduced by nearly half (each with p < 0.01) and both taste bud volume and taste cell number decreased 30% (each with p< 0.01). These experiments demonstrate that BDNF is required for maintenance of normal levels of taste innervation and normal taste bud morphology in adulthood. In addition, taste cells expressing PLCß2 (phospholipase C ß2), a marker for taste cells that respond to sweet, bitter and umami, did not decrease after Bdnf gene deletion in the adult. Thus, the missing taste cells are of another type. This indicates that taste cell loss is not uniform across the various taste cell types, even if nearly all taste cell types receive the P2X3 and TUJ1 innervation. Since BDNF is required for initial innervation of the taste system and supports taste bud innervation and size in adulthood, it could also be required for nerve reinnervation after injury. To determine if Bdnf is still expressed following nerve section, the chorda tympani nerve (taste nerve) was sectioned and Bdnf level was detected with Real Time RT-PCR. Bdnf continued to be expressed at normal levels from two days to two months post-surgery in both geniculate ganglion and tongue epithelium. Therefore, BDNF could be involved with chorda tympani regeneration. To determine if this was the case, the Bdnf gene was deleted in adult inducible transgenic mice (under the control of a Ubiquitin promoter) two weeks before chorda tympani nerve section. Taste bud number was reduced by half in all genotypes at two weeks post-surgery (p < 0.01). For the remaining taste buds, gustatory innervation was nearly gone with only a little innervation from the trigeminal nerve remaining in the taste bud (p < 0.01). Taste bud volume (p < 0.01) and taste cell number (p< 0.01) were reduced by half for both control and experimental genotypes. Eight weeks post-surgery, taste bud number recovered in mice without Bdnf gene deletion, but did not recover in mice following Bdnf gene deletion (p < 0.01). Gustatory nerve innervation returned in 70% of the taste buds in control mice (p< 0.01). For those reinnervated taste buds, both taste bud volume and taste cell number increased to normal levels. However, in mice lacking the Bdnf gene, gustatory fibers only reinnervated 7.8% of the taste buds (p < 0.01); for most uninnervated taste buds, both taste bud volume and taste cell number remained small. These experiments demonstrate that BDNF is crucial for promoting regeneration of gustatory nerve fibers in adulthood. Following gustatory nerve section, considerable adult plasticity has been observed on the contralateral side including enlarged taste buds with more cells (Guagliardo and Hill, 2007). To determine if this anatomical change was associated with alter Bdnf expression. I examined Bdnf level in the geniculate ganglion and tongue epithelium on the contralateral side following chorda tympani nerve section. Results showed Bdnf expression increased two fold at two weeks post-surgery in geniculate ganglion on the contralateral side (p < 0.05), indicating BDNF may involve with the observed plastic changes. To determine if the increase in taste bud size was associated with increased innervation and/or regulated by BDNF, the Bdnf gene was then deleted in inducible knockout mice before nerve surgery, and taste bud size and amount of innervation were measured on the contralateral side. The results showed taste bud volume, taste cell number and a marker for nerve fibers all increased on the contralateral side in mice without Bdnf gene deletion at eight weeks post-surgery. This indicates that larger taste buds could be supported by increased TUJ1 positive fibers from trigeminal nerve. In addition, in mice lacking Bdnf, taste bud volume, taste cell number and innervation did not increase on the contralateral side after surgery, which indicates that Bdnf may contribute to larger taste buds on the contralateral side following nerve section by supporting increased innervation to the larger taste buds.
Identification Of A Treatment-Resistant, Ketamine-Sensitive Genetic Line In The Chick Anxiety-Depression Model, Stephen Walter White
Identification Of A Treatment-Resistant, Ketamine-Sensitive Genetic Line In The Chick Anxiety-Depression Model, Stephen Walter White
Electronic Theses and Dissertations
Approximately 60% of Major Depressive Disorder (MDD) patients do not respond to FDA-approved antidepressants. Introducing effective pharmacotherapies for this treatment-resistant population is hindered by the lack of pre-clinical screening assays that accurately model the clinical features of TRD. The purpose of this research was to screen representatives of different classes FDA-approved antidepressants and one novel antidepressant in two genetic lines of domestic fowl chicks that have previously been identified as stress-vulnerable and stress-resilient in the chick anxiety depression model. Separate groups of socially raised Black Australorp (stress-vulnerable) and Production Red (stress-resilient) chicks were administered the tricyclic antidepressant imipramine (0-20 mg/kg), …
A Neurophysiological Examination Of Stress Control In Martial Artists, Jack Pemment
A Neurophysiological Examination Of Stress Control In Martial Artists, Jack Pemment
Electronic Theses and Dissertations
The philosophies behind many martial arts often claim that by practicing martial arts individuals can gain better control over stress. We tested this idea by using controlled physical stressors to elicit an acute stress response from martial artists (n=15) and non-martial artists (n=18). To measure the extent of the stress response, we looked at changes in heart rate, respiratory sinus arrhythmia, and galvanic skin level. These three measures explore both parasympathetic and sympathetic responses, and changes in these variables continue to be explored in studies of stress and reactive aggression. In addition to our physical stressors we also exposed individuals …