Doctor of Philosophy (PhD), Wright State University, 2009, Biomedical Sciences PhD

Motoneurons are among the best studied neurons in the central nervous system. The motoneuron synapses have been well characterized in the periphery where they release acetylcholine at the neuromuscular junction. However excitatory amino acids also seem to be released from motoneuron terminals in the periphery, and centrally at their synapses contacting Renshaw cells. Although excitatory amino acids are suggested to be released from motoneuron synapses it is not known which excitatory amino acids (either aspartate or glutamate) are released, nor is the mechanism for their release known. To examine the presence and mechanism of release for aspartate and glutamate at motoneuron synapses on Renshaw cells, several immunocytochemistry experiments using both epifluorescence and electron microscopy techniques were used to determine if any of the known vesicular glutamate transporters (VGLUTs) or other transporters were present and to quantify the enrichment of aspartate and glutamate in these terminals. Moreover, immunofluorescent experiments using the Hb9::EGFP mouse model were done to confirm the specificity of VAChT immunolabeling for identifying motoneuron contacts on calbindin immunoreactive (-IR) Renshaw cells. The results from these experiments show that the known VGLUTs are not detectable at motoneuron contacts on Renshaw cells, and therefore aspartate and glutamate must be released via a VGLUT-independent mechanism. Immunofluorescent experiments with HB9::EGFP mice confirmed that VAChT is an appropriate marker for labeling motoneuron contacts on Renshaw cells. Electron microscopy experiments determined that both glutamate and aspartate are enriched in VAChT-IR contacts on Renshaw cells. Further immunofluorescent experiments looking for potential transporters for packaging excitatory amino acids into synaptic vesicles revealed that both SLC10A4 and SLC17A5 (members of the solute carrier protein family that also include the VGLUTs) were present in motoneurons. SLC10 (open full item for complete abstract)

Committee: Francisco Alvarez PhD (Advisor); Dan Halm PhD (Committee Member); Barbara Hull PhD (Committee Member); James Olson PhD (Committee Member); Robert Putnam PhD (Committee Member); Stephen Schneider PhD (Committee Member) Subjects: Anatomy and Physiology

Doctor of Philosophy, The Ohio State University, 2004, Veterinary Biosciences

We examined virological, neuropathological, and neurochemical parameters of cats infected at 3 days and 2 months of age. Following intravenous infection of neonatal cats with 1000 tissue culture infectious doses-50% of the Maryland strain of FIV, plasma viral loads were 6,600 to 1,200,000 copies per ml. Plasma loads did not correlate with leukocyte proviral loads; latencies of auditory, visual, and sensory evoked potentials; or brain viral and proviral loads. Of 16 cats tested, viral RNA was undetectable in frontal cortex of 13 and of caudate nucleus 14. Brain proviral load was detected in all cats tested. Infected cats in this study did not develop clinical neurological signs or AIDS. Cerebral subcortical white matter volume was reduced in cats infected as neonates and killed 3 months post inoculation (MPI), but was normal 6 MPI. Caudate nucleus volume was reduced 19% in cats infected as juveniles and killed 6 and 24 MPI compared to 6 month old controls . Cerebral neocortical gray matter volume was decreased 14% in cats infected as juveniles and killed 24 MPI compared. Histopathological lesions of cats infected as juveniles and adults (6 months old at infection) consisted of minimal lymphocytic infiltrates. No neuronal loss was observed by either necrotic or apoptotic mechanisms using fluoro-jade and stereological techniques. Neurochemical analysis of the caudate nucleus of cats infected as neonates revealed increased dopamine content at 3 and 18 MPI . Tyrosine hydroxylase immunoreactivity was increased 6 and 18 MPI . Tyrosine hydroxylase enzyme activity was increased only at 3 MPI. In the caudate nucleus, glutamate transporter (GLT1) mRNA was decreased 3 MPI and Glutamate was decreased 6 MPI. In the frontal cortex, glutamine synthetase activity was decreased 3 and 6 MPI, but glutamine was elevated at 3 MPI. In summary, lack of correlation between viral load and electrodiagnostics suggests host responses to infection perpetuate functional disturbances. Neocortical (open full item for complete abstract)

Committee: Lawrence Mathes (Advisor) Subjects:

Master of Science in Pharmaceutical Science (MSP), University of Toledo, 2012, College of Pharmacy

Relapse to alcohol use after prolonged withdrawal periods is a major problem in the treatment of alcohol addiction in humans. Recent preclinical research has focused on identifying long-term neuroadaptive changes and identifying the behavioral, environmental, and neuronal mechanisms underlying drug relapse. By doing so, potential new avenues for relapse prevention may be developed. Current research suggests that changes in glutamatergic neurotransmission may significantly contribute to alcohol relapse and alcohol addiction. Alcohol dependence has been linked specifically to the increased extracellular glutamate levels in key regions of neurocircuits mainly the mesocorticolimbic circuit. Based on the fact that glutamate transporter1 (GLT1) is responsible for the removal of the majority of extracellular glutamate, we hypothesized that the activation of GLT1 by the use of ceftriaxone, a β-lactam antibiotic, known to elevate GLT1 expression, would attenuate alcohol consumption in alcohol-preferring (P) rats and ultimately prevent relapse to alcohol-seeking behavior. Statistical analyses showed that P rats treated intraperitoneally with ceftriaxone, exhibited a significant reduction in alcohol consumption followed by a period of alcohol deprivation as compared to saline-treated P rats. Preliminary data with Western blot suggests that activation of GLT1 may play a key role in preventing relapse to alcohol-seeking behavior, and ultimately implicate its potential role as a therapeutic-target for treatment of alcohol dependence.

Committee: Youssef Sari PhD (Committee Chair); Ming-Cheh Liu PhD (Committee Member); Zahoor Shah PhD (Committee Member) Subjects: Pharmacology

Bachelor of Science, Wittenberg University, 2024, Biochemistry/Molecular Biology

Obsessive compulsive disorder (OCD) is a neuropsychiatric disorder in which individuals can suffer from obsession, compulsions, and uncontrollable thoughts. Current treatments for OCD are not effective for all individuals, but an over-the-counter drug, N-acetyl cysteine (NAC), has shown promising therapeutic effects for those affiliated with OCD. In a past behavioral study, mice were separated into groups and given NAC for one or three weeks and then given RU24969, which is a 5-HT1B serotonin receptor agonist that induces perseverative behavior, a common characteristic of OCD in mice. The mouse brains were then homogenized, mRNA was extracted, and cDNA was created. The Quantitative Polymerase Chain Reaction (qPCR) analysis was used to measure gene expression in six chosen genes: CNTN4, TNR, GRIK3, GRIA2, SLC6A4, and ADRA2A and two reference genes. Gene expression was measured in seven different treatment groups with varying conditions including normal mice, those with OCD like symptoms, and those treated with NAC. These genes are involved in the nervous system in some way, which could mean there is a link between their activity and OCD. The trend in the data for these genes showed significant increases in gene expression in the 1-week NAC + water treatment and decreases in the 3-week NAC + RU treatment.

Committee: Michelle McWhorter (Advisor); Gwynne Davis (Committee Member); Cathy Pederson (Committee Member) Subjects: Mental Health; Neurobiology; Neurology; Neurosciences; Psychology

PhD, University of Cincinnati, 2023, Arts and Sciences: Chemistry

Human ADP-ribosyl-acceptor hydrolases (hARHs) are a family of metalloenzymes that can reverse site-specific ADP-ribosylation, a post-translational modification that regulates a wide array of important cellular signaling pathways, such as DNA repair and cellular death. ADP-ribosylation is typically catalyzed by two families of ADP-ribosyl-transferases (ARTs), diphtheria toxin-like (ARTDs) or cholera toxin-like (ARTCs). Each family has distinctive methods of transferring monomeric or polymeric ADP-ribose units from ß-NAD+ to target proteins. While ADP-ribosylation is important for cellular signaling pathways, such as DNA damage responses, certain bacterial toxins use this modification to produce toxins. Furthermore, uncontrolled accumulation of ADP-ribosylated products often results in mis-regulated cell signaling and diseases, e.g., cancer. Reversal of ADP-ribosylation by ARH3 and ARH1 is specific to the type of modified residues. ARH1 specifically reverses the N-glycosidic linkage of arginine specific mono-ADP-ribosylation, while ARH3 targets serine specific modifications. Crystal structures of ARH1 in complex with ADP-ribose (published in 2018) show a bi-metallic Mg2+ center. Additionally, it is suggested that Mg2+ seems to support optimal enzymatic efficiency. Notably, our group previously identified a flexible Glu41-flap of ARH3, a substrate-binding element that provides plasticity to the protein for its hydrolysis activity. Mutation of this site results in impaired enzymatic activity when attempting hydrolysis. However, these previous studies failed to provide further insights into a variety of factors. First, it is unclear if Mg2+ is the metal cofactor that can produce the optimal hydrolase activity for ARH1. The lack of insights into the structural and enzymatic effects of other divalent metals, in place of Mg2+, could provide clues on whether Mg2+ is truly required for optimal enzymatic activity. In fact, I found that activity of human ARH1 is dependent on Mn (open full item for complete abstract)

Committee: In-Kwon Kim Ph.D. (Committee Chair); Pearl Tsang Ph.D. (Committee Member); George Stan Ph.D. (Committee Member) Subjects: Chemistry

Master of Science, The Ohio State University, 2023, Materials Science and Engineering

The etiology, pathogenesis, and diagnosis of various neurological disorders can be determined though quantitative measurement of neurotransmitter concentration levels within the central nervous system (CNS). Glutamate is an important excitatory neurotransmitter and has been shown to be upregulated in various neurological disorders such as traumatic brain injury, Alzheimer's disease, and epilepsy. Most glutamate-based sensors are amperometric, and therefore require bulky electrical components (e.g. power supply) that result in difficulty for integration into neural tissue. In this paper we outline a biofuel cell-based sensor that employs glutamate oxidase as the catalyst on the working electrode. We first demonstrate the performance of the biofuel cell using commercial electrodes and a high surface area material (carbon nanotubes, (CNT) or Platinum Black). We then perform a systematic study on factors that improve biofuel cell performance. Lastly, we perform glutamate measurements on mice brain homogenate and on the hypothalamus of organotypic brain slices from neonatal mice following electrical stimulation. These results indicate that continuous glutamate measurement from a specific region of the brain (e.g., hypothalamus) is possible and can serve as a diagnostic tool against TBI and stroke, especially when paired with wireless technology (e.g., Bluetooth). This sensor can also be applied to other neurotransmitters, which could revolutionize neuroscience as the effect of dysregulation of neurotransmitters on neuronal cell signaling pathways can be studied more extensively.

Committee: Heather Powell (Committee Member); Jinghua Li (Advisor) Subjects: Materials Science

Doctor of Philosophy, The Ohio State University, 2022, Food Science and Technology

Increasing population growth from the current 7.7 billion to 9.7 billion in 2050 (UnitedNations, 2022) combined with changing socio-economic background has led to an increased demand for sustainably-produced protein-rich foods. Among the different protein options, plant-based protein such as (PPI) is growing in popularity for the production of plant-based meats, snack bars, and protein powders due to its high protein content and good emulsifying functionality. However, consumers' acceptability of PPI-based food products is limited by the presence of aversive attributes such as “beany”, “grassy”, “bitter”, and “astringent”. Previous studies have focused on the characterization of volatile flavor compounds in PPI, but the understanding of the key non-volatile flavor compounds is still limited. This dissertation specifically focused on the non-volatile compounds that elicit the umami and bitter taste attributes of PPI. The umami taste attribute of pea protein ingredients can be desirable or undesirable based on the food application. The compounds contributing to the umami taste perception of PPI were investigated. Initial prep-LC sensory-guided fractionation of a 10% aqueous PPI solution revealed one well-known compound, monosodium glutamate (MSG), however it was reported at a subthreshold concentration. Umami enhancing compounds 5'-adenosine monophosphate (AMP) and 5'-uridine monophosphate (UMP) were further identified after the LC fractionations were re-evaluated with MSG. Sensory recombination studies confirmed AMP and UMP were umami enhancers of MSG and all compounds contributed approximately 81% of the perceived umami intensity of the PPI. The aversive bitter taste of pea protein ingredients limits product acceptability. Compounds contributing to the bitter perception of PPIs were investigated. Off-line multi-dimensional sensory-guided prep-LC fractionation of a 10% aqueous PPI solution revealed one main bitter compound that was identified by fourier trans (open full item for complete abstract)

Committee: Devin Peterson (Advisor); Abraham Badu-Tawiah (Committee Member); Emmanouil Chatzakis (Committee Member); Christopher Simons (Committee Member) Subjects: Food Science

Doctor of Philosophy, The Ohio State University, 2022, Neuroscience Graduate Studies Program

Continuous neurogenesis in the adult hippocampus is a remarkable example of mammalian brain plasticity and is an important process for certain forms of learning and memory. Neural stem cells (NSCs) are the source of adult-born neurons, and the maintenance of this cell population throughout the lifespan is highly regulated by integrating cell-internal and -external signaling. Neurotransmitter signaling regulates adult hippocampal neurogenesis under basal conditions and may be an important mechanism coupling stimulated physiological states or disease conditions to changes in neurogenic output. Glutamate, the main excitatory neurotransmitter in the brain, may regulate neurogenesis by recruiting quiescent NSCs to re-enter the cell cycle, proliferate, and produce neuronal progeny. However, the molecular mediators by which NSCs sense and respond to glutamate signaling are unclear. The prevailing model in the literature is that glutamate stimulates receptors expressed at the plasma membrane of NSCs, triggering pro-proliferative intracellular cascades. However, few studies directly test this idea. Here, we present data that do not support a role for glutamate receptors in regulating the response of NSCs to glutamate, but rather implicate excitatory amino acid transporter 1 (EAAT1). We report that while cultured NSCs derived from adult rodent hippocampus express EAATs, ionotropic receptors, and metabotropic receptors, of these molecules only EAAT1 is necessary for NSCs to increase cell cycle entry in response to glutamate (Chapter 2). Using RNA sequencing, we demonstrate that cultured NSCs treated with glutamate upregulate gene expression related to lipid, amino acid, and protein synthesis in an EAAT-dependent manner, while NSCs experiencing EAAT inhibition upregulate quiescence-related and downregulate mitotic-related gene expression (Chapter 3). We also investigated potential downstream effectors of EAAT signaling, and find evidence supporting stored calcium release, gluta (open full item for complete abstract)

Committee: Elizabeth Kirby (Advisor); Benedetta Leuner (Committee Member); C.L. Glenn Lin (Committee Member); Min Zhou (Committee Member) Subjects: Cellular Biology; Neurobiology; Neurosciences

Doctor of Philosophy (PhD), University of Toledo, 2019, Biomedical Sciences (Neurosciences and Neurological Disorders)

A majority of Methamphetamine (Meth) users also have Alcohol Use Disorder. However, the neurochemical causes and consequences of the comorbid exposure to alcohol and Meth are unknown. We hypothesized that alcohol produces an insult to peripheral organs (i.e., liver and/or gut) that enhances the neurotoxicity to Meth. Sprague Dawley rats received ethanol by gavage for 7 days prior to a binge Meth injection regimen. EtOH did not affect Meth-induced liver damage, plasma ammonia, or hyperthermia. In other experiments, rats were allowed intermittent drinking access to EtOH every other day for 28 days, followed by the binge dosing paradigm of Meth. EtOH alone increased gut inflammation, lipopolysaccharide (LPS) and pro-inflammatory cytokines in the circulation, and LPS and cyclooxygenase-2 (COX-2) in the striatum. EtOH also decreased glutamate aspartate transporter (GLAST) immunoreactivity and increased basal extracellular glutamate concentrations in the striatum. Subsequent Meth exposure exacerbated EtOH-induced increases in LPS and cytokines in the circulation, microglial activation in the substantia nigra pars compacta (SNc), increases in extracellular glutamate and caspase-3 mediated spectrin proteolysis in the striatum, as well as the activation of cleaved caspase-3 in dopamine cells in the SNc. EtOH+Meth enhanced the long-term depletions of dopamine and serotonin in the striatum and serotonin in the prefrontal cortex compared to either EtOH or Meth alone. Dopamine cell loss in the SNc was paralleled by motor deficits via rotarod test. Glutamate-mediated excitotoxicity and inflammation were targeted as possible mechanisms as they are known mediators of neurotoxicity. Ceftriaxone is known to protect against excitotoxic insults and was injected intermittently on the days without EtOH drinking. Ceftriaxone attenuated the decreases in GLAST and the enhanced extracellular glutamate concentrations, spectrin proteolysis, and striatal dopamine depletio (open full item for complete abstract)

Committee: Bryan Yamamoto PhD (Committee Co-Chair); Joshua Park PhD (Committee Co-Chair); Nicolas Chiaia PhD (Committee Member); David Giovannucci PhD (Committee Member); F. Scott Hall PhD (Committee Member) Subjects: Neurosciences

Doctor of Philosophy (PhD), University of Toledo, 2018, Pharmaceutical Sciences (Pharmacology/Toxicology)

Studies have demonstrated that exposure to ethanol, cocaine, and/or methamphetamine can produce an elevation in the extracellular glutamate concentrations and downregulation in the expression of glutamate transporter 1 (GLT-1) and cystine/glutamate exchanger (xCT) in mesocorticolimbic brain regions. Previous studies on cannabinoids reported conflicting results regarding their rewarding properties and effects on neurotransmitter systems. However, less is known about the role of glutamate neurotransmission in cannabinoid dependence as well as the co-exposure of cannabinoids and ethanol. Studies from our laboratory demonstrated that parenteral administration of ß-lactam compounds can restore glutamate homeostasis in a rat ethanol dependence model, the alcohol-preferring (P) rat. Less is known about the effect of orally administered ß-lactam antibiotic on attenuation of ethanol consumption or other drugs of abuse. In the first study of this dissertation, we investigated the effect of the orally administered ß-lactam compound, Augmentin (Amoxicillin/Clavulanate), on ethanol consumption and the expression of astroglial glutamate transporters. We found that orally administered Augmentin significantly attenuated ethanol consumption in P rats as compared to the vehicle-treated group. Importantly, the attenuation of ethanol consumption was associated with a significant upregulation of GLT-1 and xCT expression in the nucleus accumbens (NAc) and prefrontal cortex (PFC). There was no effect of oral Augmentin treatment on glutamate/aspartate transporter (GLAST) expression in either the NAc or PFC. In the second study, we tested the effects of co-exposure with ethanol and CP 55,940, a cannabinoid receptor 1 (CB1R) agonist, on ethanol intake and CP 55,940-induced reinstatement in P rats using the conditioned place preference (CPP) procedure. We revealed a significant reduction in ethanol intake during the conditioning phase with CP 55,940 intraperitoneal (i.p.) injection (open full item for complete abstract)

Committee: Youssef Sari Prof. (Advisor); Howard Casey Cromwell Dr. (Committee Member); Frank Scott Hall Dr. (Committee Member); Zahoor Shah Dr. (Committee Member); Frederick E. Williams Dr. (Committee Member) Subjects: Neurosciences; Pharmacology

Doctor of Philosophy (PhD), University of Toledo, 2018, Experimental Therapeutics

Alcoholism and opioid addiction are a significant issue worldwide. According to the National Institute on Alcohol Abuse and Alcoholism, the lifetime incidence of alcohol use to the point of intoxication for is 86.4% for US adults (>17 years of age). Concurrent ethanol use is very common among illicit opioid users. Evidence shows a strong association between opioid and alcohol use and changes in glutamate homeostasis. Therefore, in this project, we investigated the effects of hydrocodone (HYD), which is one of the most prescribed opioid drugs in the United States, on the expression of key astroglial glutamate transporters. Primary astrocyte cell cultures were used to examine the expression of astroglial glutamate transporter 1 (GLT-1), cystine-glutamate transporter (xCT), and glutamate/aspartate transporter (GLAST). We found that treatment of primary astrocytes for five days with HYD caused downregulation of GLT-1 and xCT expression, but no effect was observed on GLAST expression. Relapse to opioids is one of the most challenging aspects of opioid addiction. Accordingly, we investigated HYD reinstatement of drug-seeking behavior using the conditioned place preference (CPP) in alcohol-preferring (P) rats. We found that HYD reinstatement is associated with reduction in xCT expression in the nucleus accumbens (NAc) and hippocampus (HIP). We then examined the effects of ceftriaxone (CEF), a ß-lactam compound known to upregulate GLT-1 and xCT, on HYD reinstatement. We found that CEF treatment attenuated the reinstatement to HYD and restored xCT expression in the NAc and HIP. Finally, as ethanol co-abuse commonly occurs with prescription opioids, we investigated the effects of chronic ethanol drinking and HYD reinstatement on astroglial glutamate transporters in P rats. HYD and ethanol exposure caused downregulation of both GLT-1 and xCT expression in the NAc, dorsomedial prefrontal cortex (dmPFC) and HIP. However, CEF attenuated HYD-reinstatement and reduce (open full item for complete abstract)

Committee: Youssef Sari (Committee Chair); F. Scott Hall (Committee Member); Zahoor Shah (Committee Member); Amit K. Tiwari (Committee Member) Subjects: Nanoscience; Neurobiology; Pharmacology; Pharmacy Sciences

Doctor of Philosophy (PhD), University of Toledo, 2018, Experimental Therapeutics

Impairments in glutamatergic and dopaminergic systems have been suggested to mediate the development of drug dependence, including dependence to nicotine (NIC) and ethanol (EtOH). Several studies reported that chronic exposure to drugs of abuse decreased the expression of glutamate transporter-1 (GLT-1) as well as cystine/glutamate antiporter (xCT) but not glutamate/aspartate co-transporter (GLAST), which consequently increased extracellular glutamate concentrations in mesocorticolimbic brain regions. In the present studies, for the first time, we investigated the effects of chronic exposure to electronic (e)-cigarette vapor containing NIC, for one hour daily for three or six months, on GLT-1, xCT and GLAST expression in frontal cortex (FC), striatum (STR) and hippocampus (HIP) in mice. In these studies, we also investigated the effects of e-cigarettes on the expression of alpha-7 and alpha-4/beta2 nicotinic acetylcholine receptors (nAChR), major pre-synaptic nicotinic receptors on the glutamatergic and dopaminergic terminals, respectively, which regulate glutamate and dopamine release. High Performance Liquid Chromatography (HPLC) was used to detect the concentrations of neurotransmitters in the FC and STR of mice exposed to e-cigarette vapor for six months. In these studies, we found that chronic exposure to e-cigarette vapor-containing NIC upregulated alpha-7 nAChR and alpha-4/beta-2 nAChR in the FC, STR and HIP. However, the expression of alpha-7 nAChR in the HIP was not changed after three or six month inhalation of e-cigarette vapors. Additionally, e-cigarette vapors inhalation for three or six months induced downregulation on GLT-1 in the STR and xCT in the STR and HIP. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques detected concentrations of NIC and cotinine, a major metabolite of NIC, in central brain regions involved in drug reward and reinforcement. Alternatively, we found that STR dopamine tissue content was decreased in mi (open full item for complete abstract)

Committee: Youssef Sari (Committee Chair); F. Scott Hall (Committee Member); Isaac Schiefer (Committee Member); Amit Tiwari (Committee Member) Subjects: Neurobiology; Neurology; Neurosciences; Pharmaceuticals; Pharmacology; Pharmacy Sciences

PHD, Kent State University, 2017, College of Arts and Sciences / School of Biomedical Sciences

The ability to localize sound in space is an important task for communication and survival in complex acoustic environments for both humans and animals. For localizing sound in the horizontal plane, differences in sound information received by each ear generates binaural cues, such as the interaural level difference (ILD). Using whole-cell recordings in brain slices, this work focuses on the basic properties of synaptic inhibition in the avian ILD circuit, as well as the modulation of inhibition in the mammalian ILD circuit, both of which are critical for understanding the range of cellular sound localization coding solutions. In birds, the posterior portion of the dorsal nucleus of the lateral lemniscus (LLDp) encodes the ILD, but little is known about the mechanisms of synaptic inhibition underlying the ILD coding. Here, I provide the first evidence confirming a monosynaptic inhibition driven by direct electrical and chemical stimulation of the contralateral LLDp. Additionally, inhibition to LLDp neurons was largely GABAergic, although there is evidence for a glycinergic component, and the low internal chloride concentration suggests a hyperpolarizing action of inhibition in this circuit. In mammals, the medial nucleus of the trapezoid body (MNTB) provides synaptic inhibition to many auditory brainstem nuclei including the mammalian ILD encoding nucleus, and thus contributes to ILD coding. However, not much is understood of the synaptic inhibition the MNTB itself receives and it remains entirely unknown how this inhibition is regulated. Here, I investigated group I metabotropic glutamate receptor (mGluR I) modulation of the glycinergic and GABAergic inputs to MNTB neurons in both wildtype (WT) mice and a fragile X syndrome (FXS) mouse model, in which the fragile X mental retardation gene 1 is knocked out (Fmr1 KO). Loss of the FMR protein results in exaggerated activity of mGluR I, allowing for comparisons of mGluR I function under normal and disordered conditions (open full item for complete abstract)

Committee: Yong Lu Ph.D. (Advisor); Jeffrey Wenstrup Ph.D. (Committee Member); Merri Rosen Ph.D. (Committee Member); Christine Crish Ph.D. (Committee Chair); Sean Veney Ph.D. (Committee Chair) Subjects: Cellular Biology; Neurobiology; Neurosciences

Master of Science, University of Toledo, 2015, Pharmaceutical Science

Alcohol and methamphetamine are one of the most widespread drugs of abuse. Recently, studies are focusing on the association between drugs of abuse and glutamatergic system. It has been found that both alcohol and methamphetamine can disturb glutamate transport, release, and clearance. Alternatively, ceftriaxone, known to upregulate one of the major glutamate transporters glutamate transporter 1 (GLT-1), showed a promising effect against cocaine seeking, methamphetamine reinstatement in conditioned place preference, and alcohol consumption. These effects are suggested to be associated in part with upregulation of GLT-1 expression levels in central reward brain regions leading to normalization of extracellular glutamate concentrations in these regions. However, there is little known about co-abuse of alcohol and methamphetamine. Therefore, this study examined the effects of ceftriaxone on alcohol and methamphetamine co-abuse in both striatum and hippocampus of Wistar rats. Wistar rats were gavaged with ethanol 6 g/kg for seven days and injected intraperitoneally with methamphetamine 10 mg/kg, four times with two hours apart. Furthermore, studies have shown the hyperglutamatergic state with drug uses, including methamphetamine and alcohol. We suggest here that this hyperglutamatergic state might be associated with a deficit in glutamate transport. Thus, we tested ceftriaxone to prevent downregulation of GLT-1 induced by administration of both alcohol and methamphetamine. Three ceftriaxone injections were given after the administration of high doses of methamphetamine. As a result, administration of alcohol and methamphetamine caused a significant downregulation of GLT-1 expression levels as compared to control naive groups in both striatum and hippocampus. Conversely, both xCT and GLAST expression levels remained unaffected as compared to naive control group. Ceftriaxone treatment normalized the level of GLT-1 expression levels in both striatum and hippocam (open full item for complete abstract)

Committee: Youssef Sari (Committee Chair); Wissam Aboulalaiwi (Committee Member); Zahoor Shah (Committee Member) Subjects: Neurosciences; Pharmacology

PHD, Kent State University, 2015, College of Arts and Sciences / School of Biomedical Sciences

Schizophrenia is a chronic debilitating neuropsychiatric disorder estimated to affect 51 million people worldwide. Several symptom domains characterize schizophrenia, including negative symptoms, such as social withdrawal and anhedonia, cognitive impairments, such as disorganized thinking and impaired memory, and positive symptoms, such as hallucinations and delusions. While schizophrenia is a complex neuropsychiatric disorder with no single “cause”, there is evidence that the oxytocin (Oxt) system may be dysregulated in some individuals. Further, treatment with intranasal Oxt reduces some of the heterogeneous symptoms associated with schizophrenia. Since Oxt is known for its modulatory effects on a variety of social and non-social behaviors, it is perhaps not surprising that it may contribute to some aspects of schizophrenia and could also be a useful therapeutic agent. This dissertation set out to study the role of the Oxt system in the neural regulation of behaviors associated with the three symptom domains of schizophrenia.

Committee: Heather Caldwell (Advisor); Eric Mintz (Committee Member); Colleen Novak (Committee Member); Jennifer Marcinkiewicz (Committee Member); David Riccio (Committee Member) Subjects: Neurosciences

Doctor of Philosophy, The Ohio State University, 2015, Psychology

The cognitive deficits of schizophrenia are the core symptom class of the disease, but they remain largely untreated by current pharmacotherapeutic strategies. Initiatives by the NIMH, such as MATRICS, have highlighted the alpha7 nicotinic acetylcholine (alpha7) receptor as a leading target for the development of novel cognition-enhancing treatments due to its unique ability to modulate many key executive function-related neurotransmitter systems, its theorized role in the portrayal of the cognitive symptoms of schizophrenia, and its agonist's ability to reverse such deficits in preclinical models of schizophrenia. However, clinical trials conducted with several alpha7 agonists have produced mixed results. Some have theorized that these heterogeneous results in clinical trials may be caused by the indiscriminate, temporally- disengaged activation produced by direct agonists. Positive allosteric modulators (PAMs) potentiate afferent signaling without carrying any intrinsic activity, thus enhancing receptor function without mistimed, false signals. This mechanism may be more conducive to improving executive functioning, but there is a paucity of data to support this claim. Early studies in vitro indicate that alpha7 PAMs do indeed potentiate excitatory post-synaptic potentials without directly activating receptors, but no studies have tested this in vivo. The purpose of this project was to address this need by determining if two novel alpha7 PAMs would be able to potentiate glutamate release in PFC (as measured by the glutamate-sensitive microelectrode array; MEA) as a function of and dependent upon afferent stimulation. This experiment required an assay where glutamate release in the PFC was driven by afferent activation (choline) at the site where the PAMs are active (the alpha7 receptor). The mesolimbic stimulation assay, which involves stimulating the shell of the nucleus accumbens (NAcSh) with NMDA and had previously been shown to result in the dose-dependent rel (open full item for complete abstract)

Committee: John Bruno Dr. (Advisor); Gary Wenk Dr. (Committee Member); Rene Anand Dr. (Committee Member); Kathryn Lenz Dr. (Committee Member); Howard Gu Dr. (Committee Member) Subjects: Neurosciences; Psychology

BS, Kent State University, 2014, College of Arts and Sciences / Department of Chemistry and Biochemistry

Multiple Sclerosis (MS) is a neurological disease characterized by myelin destruction and loss of oligodendrocytes. Our current understanding of the mechanisms responsible for this complex disease includes contributions from both genetic and environmental factors. The influence of environmental factors can be mediated by epigenetic modifications such as the acetylation of histones. Histone deacetylases (HDACs) have been targeted as one of the enzymes regulating signal transduction in cells. We have hypothesized that epigenetic mechanisms, specifically protein lysine acetylation, may be involved in the CNS pathology of MS through modifications to proteins involved in transcriptional events important for neuron and oligodendrocyte (OL) function and survival. To our interest, we have looked into these epigenetic mechanisms and collected data from oligodendrocyte precursor cell (OPC) cultures to show that patterns of acetylation are changed in respnse to alterations in glutamate levels. Analysis of data from immunoprecipitation and western blotting suggest that changes in the levels of glutamate triggers a signaling process in which HDACs are inactivated by phosphorylation and are transported from the nucleus to the cytoplasm by a protein called 14-3-3. This suggests a connection in glutamate-induced activation of signaling intermediates with alterations in histone acetylation through regulation of HDAC activity.

Committee: Ernest Freeman Ph.D (Advisor); Jennifer McDonough Ph.D (Committee Member); Paul Sampson Ph.D (Committee Member); Ruth Leslie Ph.D (Committee Member) Subjects: Biochemistry; Neurosciences

Master of Science (MS), Wright State University, 2009, Pharmacology and Toxicology

Sarin, also known as Sarin (German agent B) is classified as a weapon of mass destruction. Sarin (O-isopropyl methyl phosphonofluoridate) is a highly toxic nerve agent originally produced for chemical warfare and has been used in terrorist activities. Sarin is an extremely potent acetylcholinesterase inhibitor with high specificity and affinity for the enzyme. High sarin doses causes death due to anoxia resulting from airway obstruction, weakness of the muscles of respiration, respiratory failure and convulsions. Current treatments are still not effective at protecting against long term effects following exposure. A current approach aims to counteract the increased glutamatergic and cholinergic neurotransmission occurring in sarin neurotoxicity. In vitro and in vivo, serotonin (5-HT) 1A agonist prevented toxicity from glutamate. We determined the neuroprotective capabilities of serotonin (5-HT) 1A agonists as novel pharmacological countermeasures to chemical warfare agents. Rodents have higher amount of carboxylesterase enzyme and requires higher doses of sarin than other species. To address this issue we administered 1.5 mg/kg of CBDP (2-/o-cresyl/-4 H-1: 3: 2-benzodioxa-phosphorin-2-oxide), which specifically blocks carboxyl esterase and makes mouse model comparable to that of human exposure. We determined 1mg/kg dose of serotonin (5-HT) 1A agonists 8-OH-DPAT from dose response curve based on neuroprotection, with toxic challenge of 1.5 mg/kg CBDP and dose of sarin yielding 25-50 % mortality. This mortality rate gave enough number of survivors with seizures and neurodegeneration for reliable baselines. Measurements were mortality, weight loss AChE activity in blood and CNS, functional observational battery (FOB) and histology compared to control and toxic challenge mice. In addition, a time response curve after toxic challenge was determined with 1mg/kg of 8-OH-DPAT at time points of 1, 15, 30, 45, 60 minutes and 2, 4, 6 hours. We observed neuroprotection by 8-OH- (open full item for complete abstract)

Committee: James Lucot PhD (Advisor); David Cool PhD (Committee Member); Khaled Elased PhD (Committee Member) Subjects: Behaviorial Sciences; Pharmacology; Toxicology

PhD, University of Cincinnati, 2011, Medicine: Neuroscience/Medical Science Scholars Interdisciplinary

Schizophrenia is a chronic and pervasive neurodevelopmental disorder that devastates the lives of nearly 1% of the population. The disorder is most commonly recognized by the manifestation of hallucinations, delusions, and bizarre or disorganized behavior. These psychotic symptoms are only one facet of this complex illness. Individuals with schizophrenia also experience disabling cognitive, affective, and social impairments. Dysfunction of brain dopamine systems, and the mesocorticolimbic system in particular, is suspected to underlie these impairments. Despite recognition of the illness throughout history, there are currently no effective interventions ameliorating the full spectrum of the illness, and the origins of schizophrenia remain unclear. Although genetic factors contribute substantially to the etiology of schizophrenia, it is clear that environmental factors have a significant pathophysiological role. Epidemiologic evidence suggests that the prenatal period represents a critical window of vulnerability to environmental insult. Multiple prenatal exposures are associated with elevated schizophrenia risk in later life, including maternal infection, psychosocial stress, malnutrition, and obstetric complications. It is theorized that a mechanism common to these diverse insults may disrupt fetal development, therefore leading to psychiatric illness. One such common factor of these prenatal events is activation of the maternal inflammatory response during pregnancy. The objective of the following work was to determine the consequences of maternal immune stimulation during pregnancy on behaviors mediated by the mesocorticolimbic dopamine system in exposed progeny. Mesocorticolimbic dopamine neurotransmission is thought to underlie psychosis symptoms, as well as their exacerbation by psychomimetic agents and psychosocial stress. Thus, these studies test the overarching hypothesis that prenatal immune activation would enhance the behavioral response to psychomimeti (open full item for complete abstract)

Committee: Neil Richtand MD (Committee Chair); James Eliassen PhD (Committee Member); Gary Gudelsky PhD (Committee Member); James Herman PhD (Committee Member); Kim Seroogy PhD (Committee Member); Charles Vorhees PhD (Committee Member) Subjects: Neurology

MS, University of Cincinnati, 2010, Pharmacy: Pharmaceutical Sciences

Non-competitive N-methyl-D-aspartate (NMDA) receptor antagonists produce psychotic symptoms in humans. In rodents, NMDA antagonists produce hyperlocomotion and stereotypies, as well as increased cortical glutamatergic neurotransmission. Several of the behaviors and cognitive impairment associated with NMDA receptor blockade appear to involve increased glutamatergic neurotransmission in the prefrontal cortex. In the present study, the increase in extracellular glutamate in the prefrontal cortex induced by MK-801 was examined in rats treated with antipsychotic agents, risperidone and paliperidone. In addition, the effects of the nitric oxide synthase inhibitor L-NAME and the GABAB receptor agonist baclofen were examined on the MK-801-induced glutamate increase in the prefrontal cortex. Furthermore basal and stimulated glutamate release in the prefrontal cortex was assessed in rats exposed prenatally to immune activation. Using in vivo microdialysis, it was determined that treatment with MK-801 (0.3 mg/kg, s.c.) significantly increased extracellular glutamate in the prefrontal cortex. The glutamate response to MK-801 was significantly attenuated in rats treated chronically for 21 days with risperidone (0.01 mg/kg/day) and paliperidone (0.01 mg/kg/day) in the drinking water, or in rats treated acutely with L-NAME (60 mg/kg, i.p.) or baclofen (5mg/kg, i.p.). Prenatal immune activation was achieved by treatment of pregnant rats on day 14 of gestation with polyinosinic:polycytidylic acid (poly I:C). Microdialysis was performed in male offspring on postnatal day 56, and it was determined the MK-801-induced increase in extracellular glutamate in the prefrontal cortex was significantly diminished in poly I:C-exposed rats. In addition, basal extracellular glutamate in the prefrontal cortex of poly I:C-exposed male rats were significantly greater than that in control animals. The elevated basal extracellular glutamate in the prefrontal cortex of poly I:C offspring was reduced t (open full item for complete abstract)

Committee: Gary Gudelsky PhD (Committee Chair); Karen Gregerson PhD (Committee Member); Neil Richtand MD (Committee Member) Subjects: Pharmacology