Department: Anatomy ![[clear]](close-x.png "Remove this limiter")
23 matches in the database.
These are records: 1 - 23.
1.
Alexander, Vincent Rasahd.
The Role of Corticotropin-Releasing Factor in the Behavior and Proinflammatory Activity of Separated Guinea Pig Pups.
Degree: MS, Anatomy, 2012, Wright State University
► Isolation of guinea pig pups in a novel environment first produces active…
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▼ Isolation of guinea pig pups in a novel environment first produces active behaviors such as vocalizing and movement; over time, these behaviors wane and pups show characteristic passive responses similar to those produced by increased proinflammatory activity. Further, isolation of pups on two consecutive days has recently been shown to enhance those passive responses on the second day. Endogenous proinflammatory activity is thought to mediate the enhancement (sensitization). An injection of corticotropin-releasing factor (CRF) has been shown to increase passive behavior, possibly by increasing proinflammatory activity. The present study further investigated the role of CRF on proinflammatory activity and behavior during separation. In Experiment 1, pups were subcutaneously injected with 10µg of CRF or saline vehicle and then placed in a novel environment for 3 hr. CRF-injected pups exhibited more passive behavior and increased expression of the proinflammatory cytokine tumor necrosis factor alpha in the paraventricular nucleus of the hypothalamus when compared to saline injected pups. CRF increased plasma cortisol levels confirming that CRF activated the hypothalamic-pituitary-adrenal axis. In Experiment 2, pups were injected with either 75µg d-Phe12-41(CRF12-41), a corticotropin releasing factor antagonist, or saline vehicle and separated for 3 hr on two consecutive days. CRF12-41 increased active behaviors on Day 1. Passive behavior during separation was minimally affected by administration of the antagonist. In addition, passive responses increased from Day 1 to Day 2 in both the CRF12-41 and saline groups. Together, these findings provide evidence that exogenous CRF increases passive behavior through a proinflammatory mechanism, but also raise questions about the role of endogenous CRF in the separation response.
Advisors/Committee Members: Hennessy, Michael.
Subjects: Behavioral Psychology; Behavioral Sciences; Neurosciences; Psychobiology; Psychology
Keywords: Maternal Separation; Corticotropin-Releasing Factor; Proinflammatory; Cytokine; Depressive-like behavior
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2.
Burlon, Drew C.
THE PRESYNAPTIC REGULATION OF ISOLATED NEONATAL RAT CAROTID BODY TYPE I CELLS BY HISTAMINE.
Degree: MS, Anatomy, 2009, Wright State University
► It has been previously shown that Carotid Body Type I cells have…
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▼ It has been previously shown that Carotid Body Type I cells have the ability to synthesize, package and release histamine in response to hypoxia, thereby contributing to the modulation of respiration within the rat. Here, isolated neonatal rat carotid body type I cells were used to identify the presynaptic effects of histamine and the specific receptor subtypes that modulate them. Although all four histamine receptor subtypes are expressed on the type I cells, and preliminary data showed promising results, further data proved that the activation of these receptors with histamine or selective agonists caused no rise in intracellular calcium ([Ca2+]i) and histamine did not augment calcium entry. Thus activation of histamine receptors on type I cells is unlikely to provide a presynaptic positive feedback mechanism during chemotransduction and any excitatory role attributed to the actions of histamine is likely to come from a postsynaptic effect on the carotid sinus nerve (CSN).
Advisors/Committee Members: Wyatt, Christopher.
Subjects: Cellular biology
Keywords: Histamine; carotid body
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3.
Caraway, Jessie.
Sensitization of behavioral response to maternal separation: persistence of the effect and role of proinflammatory activity.
Degree: MS, Anatomy, 2010, Wright State University
► Maternal separation in guinea pigs produces a biphasic response consisting of an…
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▼ Maternal separation in guinea pigs produces a biphasic response consisting of an active behavior phase followed by a phase of passive behavior (crouched stance, piloerection, and eye closure). Previous studies suggest that pro-inflammatory cytokines mediate passive behavior during the passive phase. It is also known that guinea pig pups separated on two consecutive days show a significant increase (sensitization) in full passive behavior on the second day. The current study examined the persistence and role of pro-inflammatory activity in the sensitization of passive behavior in maternally separated guinea pigs. Guinea pig pups were assigned to one of four groups differing in their treatment on Day 1. The groups were either: (1) injected with saline and not separated; (2) injected with saline and separated; (3) injected with lipopolysaccharide (LPS) to induce cytokine activation and not separated; or, (4) injected with LPS and separated. All pups were separated on Day 2 and again on Day 5. By Day 5, sensitization of passive behavior was observed for all groups. LPS on Day 1 did not increase passive behavior on Day 2, but appeared to enhance the effect of separation on Day 5. These data indicate that sensitization of the passive behavior of maternally separated pups persists beyond a single day. Further the results show that LPS induced activation of pro-inflammatory activity is not sufficient to account for the initial sensitization, but does appear to enhance later sensitization effects.
Advisors/Committee Members: Hennessy, Michael.
Subjects: Psychobiology
Keywords: Cytokines; sensitization; maternal separation
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4.
Dazey, Jennifer.
Influence of Daily Electrical Stimulation of Periaqueductal Grey on Vocalization and Depressive-like Behavior during Separation in Guinea Pigs.
Degree: MS, Anatomy, 2012, Wright State University
► Maternal separation has been shown to promote the onset of depression. This…
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▼ Maternal separation has been shown to promote the onset of depression. This early life stressor produces a biphasic response marked by an active “protest” phase followed by a passive “despair” phase in humans as well as several other species. In infant guinea pigs, active phase behaviors include increased locomotion and species-typical distress vocalizations, whereas the passive phase is marked by depressive-like behaviors including a crouched stance, eye-closure and extensive piloerection. The mechanism underlying the transition from one phase to the next is still unknown. The purpose of this study was to determine if daily stimulation of the neural pathway initiating the active behaviors would lead to enhanced expression of the passive behaviors. Guinea pigs were separated into experimental and control groups. The control group received daily stimulation of a brain region not anticipated to produce vocalizations (cortex) while the experimental group received daily stimulation of the periaqueductal grey (PAG). Although stimulation of the PAG produced vocalizations that decreased across the 10 days of testing, the PAG stimulated animals did not show more passive depressive-like behaviors than pups receiving control-region stimulation.
Advisors/Committee Members: Hennessy, Michael.
Subjects: Behavioral Sciences; Behaviorial Sciences; Psychology
Keywords: social separation, vocalization, depressive response, electrical brain stimulation,periaqueductal grey, guinea pig
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5.
Deardorff, Adam S.
Developmental Expression of Calcium Buffering Proteins in Central Auditory Pathways of Normal Hearing and Congenitally Deaf Mice.
Degree: MS, Anatomy, 2010, Wright State University
► These experiments analyze differences in synaptic development in central auditory pathways between…
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▼ These experiments analyze differences in synaptic development in central auditory pathways between normal hearing (CBA/J) and congenitally deaf (dn/dn) mice, which provide valuable insight into central synaptic plasticity corresponding to human congenital deafness. Immunofluorescent analysis of the developmental expression of the calcium buffering proteins calretinin, calbindin d-28k, and parvalbumin at various postnatal time points was performed to assess the effects of altered neural activity on the level and/or pattern of protein expression within these nuclei. Results indicate that the pattern of calbindin and parvalbumin is unaffected by congenital deafness in dn/dn mice. However, the pattern of calretinin expression in the MNTB during development of dn/dn mice differed significantly from that of CBA/J mice, indicating that calcium buffering may be impaired in these synapses without appropriate afferent stimulation.
Advisors/Committee Members: Fyffe, Robert E.W.
Subjects: Biomedical research; Neurology
Keywords: Auditory Pathways; Calcium Buffering Proteins; Calretinin; Calbindin; Parvalbumin; Congenital Deafness; Synaptic Development; dn/dn mice
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6.
Dougherty, Kevin S.
THE DEVELOPMENT AND MOLECULAR EXPRESSION IN MAMMALIAN CELLS OF AN HA-TAGGED PLASMID ENCODING FOR THE TARGET OF RAPAMYCIN (mTOR).
Degree: MS, Anatomy, 2007, Wright State University
► The protein kinase mammalian Target of Rapamycin (mTOR) is a master controller…
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▼ The protein kinase mammalian Target of Rapamycin (mTOR) is a master controller of cell growth and proliferation due to its ability to integrate growth signals and regulate translation through 4E-BP1 and p70-S6K. We developed four phCMV2-HA-tagged plasmids to overexpress TOR in mammalian cells: Wild Type, D2357E (Kinase Dead), R2109A (PA Binding Deficient) and, S2035T (Rapamycin Resistant) each verified by restriction enzyme digestion and direct sequencing. Plasmid DNA was overexpressed in COS-7 cells and the 289 kDa protein detected in Western blots developed with anti-HA and anti-mTOR antibodies. Kinase activity of the overexpressed protein was detected by in vitro phosphorylation of 4E-BP1 and S6K. QRT-PCR detected a 200 fold increase in mTOR gene expression over mock transfected cells, but found no change in PLD2 gene expression. Immunoflourescence microscopy indicated that mTOR is perinuclear, concentrated in endosomal formations. This study provides the molecular biology tools for continuing investigation into the crosstalk between mTOR, S6K, PLD1 and PLD2.
Advisors/Committee Members: Gomez-Cambronero, Julian.
Keywords: mTOR; Mammalian Target of Rapamycin; HA-tagged Plasmid; Real Time PCR; QRT-PCR; DNA Plasmid Preperation
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7.
Downing, Trevor.
THE RELATIONSHIP BETWEEN LACTIC ACID, REACTIVE OXYGEN SPECIES AND THE HYPOXIA-INDUCED ACIDIFICATION SEEN IN CHEMOSENSITIVE NEURONS OF THE NUCLEUS TRACTUS SOLITARIUS (NTS).
Degree: MS, Anatomy, 2006, Wright State University
► The NTS is one of many sites of chemoreception meaning that it…
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▼ The NTS is one of many sites of chemoreception meaning that it responds to changes in CO2 and pH. NTS neurons also acidify approximately 0.13 pH units in response to hypoxia. Experiments involved brainstem slices exposed to a control hypoxic bout followed by hypoxia in conjunction with different drugs. The drugs included fluorocitrate, 4-hydroxycinnamate, oxygen-glucose deprivation and iodoacetate. Iodoacetate produced the strongest blunting of the hypoxia-induced acidification and decreased the response by ~53%. Results from the studies using the superoxide probe DHE showed an increase in the levels of ROS during the hypoxic exposure prior to reoxygenation. Two ROS scavengers melatonin and manganese(III)tetrakis(1-methylpyridyl) porphyrin pentachloride both reduced the increase in ROS by ~30%. In conclusion, the hypoxia-induced acidification seems to be due to lactate production which is proposed to come from neuronal sources as the glial source of lactate was ruled out with the fluorocitrate and 4-hydroxycinnamate studies.
Advisors/Committee Members: Dean, Jay.
Keywords: hypoxia; ACIDIFICATION; ROS; NEURONS; glial; glial cells; NTS
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8.
Kardegar, Nadia.
Electrical Brain Stimulation and Depressive-like Behavior in Guinea Pigs.
Degree: MS, Anatomy, 2012, Wright State University
► Maternal separation in guinea pigs produces a biphasic response consisting of an…
(more)
▼ Maternal separation in guinea pigs produces a biphasic response consisting of an active behavior phase (vocalizations and locomotor activity) followed by a phase of passive depressive-like behavior (crouched stance, piloerection, and eye closure). The mechanism for the transition from the active to the passive phase is unknown. One suggestion is that continual activity of neural circuitry producing active behavior eventually leads to the expression of passive behaviors. The purpose of this study was to test this possibility. Guinea pigs were assigned to experimental and control groups. The experimental group received daily stimulation of the bed nucleus stria terminalis (BNST) to produce vocalizations. Controls included non-operated animals and those which received daily electrical stimulation of a brain area not expected to produce vocalization (parietal cortex). Stimulation of the BNST elicited vocalizations, which decreased across 10 days of testing. However, BNST-stimulated animals did not show more passive depressive-like behavior than the controls.
Advisors/Committee Members: Hennessy, Michael.
Subjects: Anatomy and Physiology
Keywords: anatomy
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9.
Moore, Jeremy Alan.
Effects of Subcutaneous Postnatal Choline Supplementation on Hippocampus-Mediated Learning and Memory in Rat Pups.
Degree: MS, Anatomy, 2008, Wright State University
► The effects of postnatal injections of choline on the acquisition of two…
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▼ The effects of postnatal injections of choline on the acquisition of two variants of eyeblink conditioning were examined in developing Long-Evans rat pups. Choline administration on postnatal days (PND) 15-27 was followed by evaluation of trace eyeblink conditioning (Experiment 1) and delay eyeblink conditioning (Experiment 2) on PND 28-29. The results of these experiments show that choline produced greater improvements in learning and memory during the trace condition than in the delay condition, presumably due to its effect on the hippocampus. Trace eyeblink conditioning relies heavily on an intact hippocampus but delay eyeblink conditioning does not, and it is understood that choline has a positive influence on hippocampal function. This was the first study to examine the effects of choline on eyeblink conditioning and provides baseline data for future research into the beneficial effects of choline for this type of learning as well as its potential neuroprotective effects for the hippocampus.
Advisors/Committee Members: Claflin, Dragana.
Subjects: Psychology
Keywords: choline; hippocampus; trace conditioning; eyeblink conditioning; learning
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10.
Novak, Kevin Richard.
EFFECTS OF SEPSIS ON NERVE EVOKED RESPONSES.
Degree: MS, Anatomy, 2008, Wright State University
► Sepsis and SIRS (systemic inflammatory response syndrome) have become two expensive and…
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▼ Sepsis and SIRS (systemic inflammatory response syndrome) have become two expensive and complicated problems seen in the intensive care unit (ICU). These two illnesses have been known to cause dysfunction with excitable tissues in the body. Encephalopathy, neuropathy, and myopathy are the three biggest. In this paper we discuss the development of an animal model of sepsis and the neurological complications sepsis brought about. Nerve conduction studies showed increased durations on compound muscle action potential, and decreased amplitude as well as increased duration and latency on sensory nerve action potentials. These results were not consistent with the two most common neuropathies, demyelinating and axonal. Collaborative efforts with the Cope lab found that action potential amplitudes of individual axons could be improved by delivering a hyperpolarizing current. This data is supported by similar findings in muscle fibers by the Rich lab.
Advisors/Committee Members: Rich, Mark.
Subjects: Neurology
Keywords: sepsis; nerve conductions; CMAP; SNAP; compound muscle action potential; sensory nerve action potential
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11.
O’Connell, Keely Jane.
Stress Reducing Effects of Oxytocin in a Maternal Separation Paradigm.
Degree: MS, Anatomy, 2008, Wright State University
► This study compared the effects of centrally and peripherally administered oxytocin (OT)…
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▼ This study compared the effects of centrally and peripherally administered oxytocin (OT) on HPA axis activity and the presence of both stress-induced active and passive behaviors in female guinea pig pups (Cavia porcellus) after 180-min of isolation . In Experiment 1, one dose of oxytocin (10μg/.2ml) was injected subcutaneously into the periphery. Plasma cortisol levels were reduced after 180-min of isolation and two passive behaviors, eye-closure and crouch, were reduced as well with the administration of oxytocin. In Experiment 2, two different doses (10μg/.2ml and 20μg/.2ml) were injected into the periphery with no significant results. In Experiment 3 one dose of oxytocin (1μg/5μl) was infused centrally. Plasma cortisol levels were marginally reduced after 30-min of isolation. Both the active and passive behaviors were unchanged.
Advisors/Committee Members: Hennessy, Michael.
Subjects: Behaviorial sciences
Keywords: oxytocin; stress; maternal separation; guinea pigs
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12.
Page, Elizabeth.
The Role of Apoptosis in HeLa Cells Expressing HIV-1 Rev.
Degree: MS, Anatomy, 2010, Wright State University
► The HIV protein Rev is a nucleolar protein that regulates late gene…
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▼ The HIV protein Rev is a nucleolar protein that regulates late gene expression in infected cells by promoting the export of under-spliced viral RNAs (Pollard and Malim, 1998). Its over-expression can also inhibit progression through mitosis (Miyazaki et al., 1995), possibly through its ability to depolymerize microtubules (Watts et al., 2000). Consequently, Rev may activate the spindle assembly checkpoint in mitotic cells and increase the frequency of apoptosis. Rev also binds the nucleolar protein B23 involved in ribosome maturation and centrosome duplication. Because loss of B23 function stimulates apoptosis (Ahn et al., 2005), Rev expression may promote apoptosis by inhibiting B23.Regardless of its mechanism, it is plausible to hypothesize that Rev expression stimulates apoptosis. To test this hypothesis, Rev and three mutants defective in multimerization, nuclear import, and nuclear export (M4, M6, and M10, respectively) and are known to cause defects in mitosis were transiently and stably over-expressed in HeLa cells. Three separate assays were then used to assay for apoptotic cell death. Since apoptosis is characterized by cell shrinkage, cell rounding, chromatin condensation and fragmentation (Kerr et al., 1993; Lawen, 2003), Rev expressing cells were fixed with formaldehyde, stained with DAPI and examined for overt signs of apoptosis. In cells transiently expressing Rev-GFP, there was a two-fold increase in apoptosis compared to YFP expressing controls. Transient expression of Rev mutants M4, M6, and M10 resulted in comparable increased frequencies of apoptosis. This visual assay is limited by the apparent lack of sensitivity as demonstrated by the inability to detect apoptosis induced by treatment with actinomycin D. To clarify these results, two additional biochemical assays were used. The first, an ELISA assay that quantifies chromatin fragmentation by measuring the release of mono- and oligo-nucleosomes, showed there was no statistical difference in apoptotic frequencies between Rev-YFP and YFP expressing cells (p=0.43). These results were confirmed by an immunoblot assay that was unable to detect the presence of activated Caspase 3 in Rev expressing cells. Thus it appears that the cell cycle defects induced by Rev expression are either corrected before mitosis is completed or not detected by the spindle assembly checkpoint.
Advisors/Committee Members: Miller, Mill.
Keywords: Rev; Rev expression; Apoptosis; Cells; microtubules; YFP; HeLa
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13.
Paik, Kristopher Doojin.
Inhibition of pro-inflammatory processes reduces sensitization of the behavioral response to maternal separation.
Degree: MS, Anatomy, 2009, Wright State University
► The current study examined the behavioral sensitization of guinea pig pups in…
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▼ The current study examined the behavioral sensitization of guinea pig pups in response to consecutive days of maternal separation. In the first experiment, guinea pigs that received centrally administered artificial cerebrospinal fluid or IL-10 exhibited sensitization of passive behaviors from Day 1 to Day 2. IL-10 decreased the levels of passive behaviors on Day 1, as well as the increase on Day 2. The second experiment used unoperated pups, which also showed sensitization of the passive response from Day 1 to Day 2, though the effect appeared reduced relative to control pups of Experiment 1. Collectively, this investigation confirms previous evidence that passive behaviors are due in part to pro-inflammatory cytokines. It also provides evidence that the increase in passive measures from the first separation to the second may be caused by a sensitization of pro-inflammatory mechanisms.
Advisors/Committee Members: Hennessy, Michael.
Subjects: Psychology
Keywords: pro-inflammatory cytokines, maternal separation, sensitization, depression, guinea pigs
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14.
Paulet, Julia.
MATURATION OF THE CAROTID BODY OXYGEN-SENSOR DURING RAT DEVELOPMENT.
Degree: MS, Anatomy, 2012, Wright State University
► Carotid bodies (CB) are paired, oxygen-sensing organs located in the bifurcation of…
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▼ Carotid bodies (CB) are paired, oxygen-sensing organs located in the bifurcation of the carotid artery that act as peripheral chemoreceptors in the detection of hypoxic, hypercapnic and acidotic levels in the arterial blood. CBs respond to these fluctuations in blood gases by initiating firing of the carotid sinus nerve. This ultimately results in the appropriate ventilatory change to restore blood gases to their physiological levels. Studies have shown that the hypoxic response of the carotid body in juvenile mammals is low, but as maturation occurs this response is strengthened and clearly exhibited in adults. One theory suggests mitochondria play a vital role in the oxygen sensitivity of Type I cells in carotid bodies. The experimental hypothesis of this project is that mitochondria in the oxygen sensing Type I cells of rat carotid bodies change in number and /or distribution during the development of the acute hypoxic ventilatory response. Type I cells were isolated from juvenile (4-6 days) and mature (14-16 days) rat carotid bodies and loaded with mitotracker to quantify mitochondrial content. Data obtained demonstrated a significant reduction in the total volume of mitochondria in Type I cells during development which was not paralleled by a fall in metabolic rate, indicating an increase in the rate of mitochondrial oxidative phosphorylation. These findings suggest that change in mitochondrial content during the development of the hypoxic response might be crucial for this mechanism's development.
Advisors/Committee Members: Wyatt, Christopher.
Subjects: Anatomy and Physiology
Keywords: anatomy; physiology
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15.
Robinson, Sergei Alexander.
AQUAPORIN 4 EXPRESSION AND DISTRIBUTION DURING OSMOTIC BRAIN EDEMA AND FOLLOWING CHRONIC TREATMENT OF DESIPRAMINE.
Degree: MS, Anatomy, 2011, Wright State University
► Osmotic brain edema or chronic treatment with desipramine alters brain water permeability.…
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▼ Osmotic brain edema or chronic treatment with desipramine alters brain water permeability. In this study we investigated aquaporin 4 expression and distribution in these two conditions. Brain edema development was induced by intraperitoneal water injection. Blood serum osmolality decreased from 296 ± 1 mOsm to 278 ± 2 mOsm within 15 min. Cerebral cortex water content increased from 79.8 ± 0.2 % to 81.3 ± 0.5% during 120 min of this hyposmotic exposure. Aquaporin 4 immunostaining intensity at the astrocytic endfeet increased in water injected animals from 2.6 ± 0.04 intensity unites (IU) to 3.2 ± 0.21 IU, while total brain AQP4 expression remained unaltered. Chronic treatment with desipramine showed no significant change in serum osmolality or cerebral cortex water content. Similar to water injected animals, aquaporin 4 immunostaining intensity in chronic desipramine animals increased at the astrocytic endfeet (2.5 ± 0.04 IU to 3.0 ± 0.13) but total cortical AQP4 expression was again unaltered. These experiments suggest that decreased brain water permeability caused by osmotic brain edema is not a result of decreased AQP4 expression or localization of astroglial endfeet. However chronic treatment with desipramine increases AQP4 immunostaining at the astrocytic endfeet without increasing overall AQP4 expression.
Advisors/Committee Members: Olson, James.
Subjects: Neurosciences
Keywords: AQP4; aquaporin 4; BBB; blood-brain barrier; TCA; desipramine; astrocytes; water permeability
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16.
Roebel, John L.
Developmental Expression of Calcium-Binding Proteins in the AVCN and MNTB of Normal Hearing and Congenitally Deaf Mice.
Degree: MS, Anatomy, 2006, Wright State University
► This experiment analyzes synaptic differences in the central auditory pathway between normal…
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▼ This experiment analyzes synaptic differences in the central auditory pathway between normal hearing and congenitally deaf (dn/dn) mice, and provides valuable insight into central changes that correspond with human congenital deafness. Specifically, this experiment analyzes developmental expression of the Calcium (Ca2+)-binding proteins Calretinin (CR), Calbindin D-28k (CB) and Parvalbumin (PV) in large excitatory synapses in the anteroventral cochlear nucleus (AVCN) and the medial nucleus of the trapezoid body (MNTB) of normal and dn/dn mice. Immunofluorescence imaging with primary antibodies detecting CR, CB or PV was used to analyze the expression of each at 9 days, 13 days, 20 days, 30 days and 49 days postnatal in normal and dn/dn mice. Results indicated that Ca2+-binding expression was similar at each location in normal and dn/dn mice at 9 days postnatal, prior to opening of the ear canal and the onset of hearing (which occurs around 11 days postnatal) . In normal mice, patterns of Ca2+-binding protein expression changed progressively after the onset of hearing. In dn/dn mice (which completely lack auditory nerve activity), however, patterns of expression did not change after the onset of hearing, suggesting that patterns of Ca2+-binding protein expression change during development in normal mice in response to evoked auditory nerve activity, and that patterns of Ca2+-binding protein expression do not change during development in dn/dn mice due to lack of evoked auditory nerve activity. As a result, Ca2+ buffering is impaired in synapses located in the AVCN and MNTB of dn/dn mice.
Advisors/Committee Members: Fyffe, Robert E.W.
Keywords: Calcium-binding proteins; deafness; auditory; Calretinin; Calbindin D-28k; Parvalbumin; AVCN; MNTB
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17.
Schneider, Randi Lynn.
Persisiting Sensitization of Depressive-Like Behavior and Thermogenic Response During Maternal Separation in Pre- and Post Weaning Guinea Pigs.
Degree: MS, Anatomy, 2011, Wright State University
► Early attachment disruption is thought to promote later onset of depressive illness…
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▼ Early attachment disruption is thought to promote later onset of depressive illness through a process involving sensitization. Maternal separation in guinea pig pups (~21 days of age) produces depressive-like behavior and core body temperature fluctuations that appear to be mediated by proinflammatory activity. These responses are enhanced during repeated separations over several days. Here, enhanced depressive-like behavior and core body temperature responses were observed from the early pre-weaning to the periadolescent period (~10-40 days of age) and persisted for more than a week. The greatest temperature response was observed during the final separation. These results demonstrate persisting sensitization of behavioral and thermogenic responses to maternal separation over the age range in which these responses are known to occur. Further, the findings are consistent with the hypothesis that proinflammatory activity contributes to the sensitization response and suggest that the impact of early attachment disruption on susceptibility to depression involves proinflammatory processes.
Advisors/Committee Members: Hennessy, Michael.
Subjects: Behavioral Psychology; Developmental Psychology; Psychobiology
Keywords: depression, core body temperature, thermogenic response, maternal separation, guinea pigs
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18.
Stuckey, Crystal Elaine.
Oxidative Stress and Cell Death in Osmotically Swollen Glial Cells.
Degree: MS, Anatomy, 2008, Wright State University
► Regulation of normal volume is an important aspect of cell homeostasis. Possible…
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▼ Regulation of normal volume is an important aspect of cell homeostasis. Possible mechanisms which signal volume regulation are increasing the rate of reactive oxygen species (ROS) production and release of ATP for interaction with purinergic receptors. We examined whether an increase in ROS production during cell swelling also led to cell injury of C6 glioma cells. Cells were loaded with 5,6-carboxy-2,7-dihydrofluorscein diacetate (DCFDA) to fluoroscopically measure the rate of cellular ROS production and were perfused with phosphate-buffered saline solutions (PBS) containing 100 μM carbenoxolone to inhibit dye efflux. Cell death was determined cytometrically and by measuring the release of lactate dehydrogenase (LDH) into the culture medium 24 hr after exposing cells for 60 min to isoosmotic or hypoosmotic PBS. Immediately after changing the perfusion solution from isoosmotic to hypoosmotic PBS, the production of ROS increased by 60.2% + 19.6, but returned to baseline after 5 min. Increased efflux of ATP was not observed in hypoosmotic conditions. ROS production was not directly activated by endogenously applied extracellular ATP, but ATP increased ROS production in swollen cells. Cells swollen by hypoosmotic solutions had a slight increase in the probability of necrotic cell death. Our data suggest that increased ROS produced by cells swollen during hypoosmotic stress does not lead to significant cell injury in cultured C6 cells.
Advisors/Committee Members: Olson, James.
Subjects: Cellular biology; Microbiology; Neurology
Keywords: C6; glia; DCFDA; hypoosmotic; ROS; ATP; cell death; NADPH oxidase; mitochondrial ETC; DPI; oligomycin; rotenone
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19.
Tabatabaian, Farnaz.
THE MEASUREMENT OF ENDOGENOUS mRNA EXPRESSION OF PLD ISOFORMS IN HL-60 CELLS USING QRT-PCR AND THE IMPACT OF THESE ISOFORMS ON GENE EXPRESSION OF mTOR AND S6K.
Degree: MS, Anatomy, 2006, Wright State University
► Phospholipase D (PLD) is an enzyme that hydrolyzes the phosphodiester bond in…
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▼ Phospholipase D (PLD) is an enzyme that hydrolyzes the phosphodiester bond in phosphatidylcholine, yielding choline and phosphatidic acid (PA). There are two main isoforms: PLD1 and PLD2, which share 50 % genetic homology. Both PLD isoforms are highly regulated by fatty acids, small GTPase proteins, protein kinase C, Ca2+, and phosphorylation. PLDs are involved in physiological and cellular signaling pathways, primarily through the production of the lipid second messengers PA and diacylglycedrol (DAG). While PA is involved in a variety of intracellular mechanisms, the role of PLD, independent of PA, in regulation of signaling protein kinases is not fully understood. This is particularly the case for the protein kinases mammalian target of rapamycin (mTOR) and ribosomal p70S6K. mTOR is a kinase, activated by growth factors and inhibited by rapamycin, that contributes to cell growth and proliferation. p70S6K, also a kinase, is a substrate of mTOR and catalyzes the phosphorylation of the S6 protein, a component of the eukaryotic ribosomal 40S subunit. P70S6K also plays a role in the regulation of cell growth. The objectives of the present study were to analyze: (a) if the expression of the PLD mRNA isoforms were subjected to regulation by the expression of members in other cell signaling pathways, namely mTOR and S6K, and (b) if such regulation should exist, how it might be modulated by granulocyte agonists, specifically chemoattractant agents Epithelial-neutrophil activating peptide (ENA-78), N-formyl-methionyl-leucyl-phenylalanine (fMLP) and Interleukin-8 (IL-8). Using a variety of molecular methodologies, we were able to establish a working method for high-yield transfection of the human promyleocyitic leukemic (HL-60), a hematopoietic cell line that grows in cell culture in suspension. Real Time PCR (qRT-PCR) was optimized for the four genes of interest in this study: PLD1, PLD2, mTOR, S6K. Using qRT-PCR, we found that DMSO differentiated HL-60 cells (dHL-60) that express the neutrophilic phenotype, were able to respond to ENA-78, fMLP, and IL-8. Gene expression of PLD1, PLD2, mTOR and S6K increased in presence of ENA-78 and IL-8. On the other hand, fMLP increased gene expression of PLD2, mTOR and S6K, but not PLD1. Endogenous gene expression after silencing with specific, double strand, small interfering RNAs (si RNA) was also investigated. PLD1 RNA interference effectively silenced PLD1, but showed a small degree of non-specific silencing towards PLD2 as well. PLD2, mTOR and S6K were effectively silenced by RNA interference. Interestingly, the silencing of the latter genes was not rescued (brought back to basal levels) by fMLP or IL-8 induction. Further, a relationship between the PLD2 and the mTOR/S6K kinases was found, namely, that when either mTOR or S6K gene expression is silenced, PLD2 expression is dramatically potentiated. We propose that mTOR and S6K expression negatively regulate PLD2 gene expression, and this cannot be rescued by cell stimulation with chemoattractants. The mechanism by which RNA from a set of cell signaling molecules influence the expression of other genes is not addressed in this thesis, but several exploring possibilities are discussed.
Advisors/Committee Members: Gomez-Cambronero, Julian.
Subjects: Biology, Cell
Keywords: dHL-60 cells,Endogenous mRNA expression of PLD1, PLD2, mTOR, and S6K
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20.
Thompson, Carrie Marie.
PRESYNAPTIC REGULATION OF CAROTID BODY TYPE I CELLS BY HISTAMINERGIC AND MUSCARINIC RECEPTORS.
Degree: MS, Anatomy, 2010, Wright State University
► Type I cells are one of two main cell types located within…
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▼ Type I cells are one of two main cell types located within the carotid body. These cells respond to hypoxia, hypercapnia, and acidosis by releasing excitatory and inhibitory neurotransmitters. This causes increased firing of the carotid sinus nerve and restores blood gas levels to their physiological values. While previous studies have shown whether individual neurotransmitters are excitatory or inhibitory, this work demonstrates how the interplay between two neurotransmitters may potentially shape the output of the carotid body. Histamine, which has previously been shown to have no effect on intracellular Ca2+ in type I cells, may function to modulate the actions of an excitatory neurotransmitter such as acetylcholine. Using Ca2+-imaging techniques, this work shows that histamine inhibits the acetylcholine muscarinic receptor-induced rise in intracellular Ca2+. Histamine, acting on the Gi-coupled H3 receptor, may exert its actions by inhibiting the activation of adenylate cyclase and therefore reducing levels of cAMP. The observed inhibition of muscarinic Ca2+ signaling seems independent of protein kinase A (PKA), as two PKA inhibitors did not mimic the inhibition. Data suggest that Gi-coupled receptor activation may inhibit muscarinic Ca2+ signaling in type I cells by the inhibition of Exchange Proteins Activated by cAMP (Epac).
Advisors/Committee Members: Wyatt, Christopher.
Subjects: Pharmacology
Keywords: carotid body; histamine; acetylcholine; epac
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21.
Titus, Haley E.
Reorganization of Ia afferent synapses on motoneurons after peripheral nerve injuries.
Degree: MS, Anatomy, 2009, Wright State University
► After peripheral nerve injuries patients lose and do not recover the stretch…
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▼ After peripheral nerve injuries patients lose and do not recover the stretch reflex which leads to altered locomotor function. The focus of this thesis is to investigate the structural integrity of the central connection between Ia afferents and alpha motoneurons that mediate the stretch reflex. The overall hypothesis is that the density and distribution of Ia synapses on motoneurons is altered after peripheral nerve injuries. Analysis of Ia afferent-motoneuron contacts, revealed by vesicular glutamate transporter 1 (VGLUT1) immunoreactivity, on the soma and dendritic arbor of motoneurons after peripheral nerve injuries revealed major reorganizations in the distribution and density of Ia synapses. Synaptic stripping of Ia afferent synapses occurred on the soma and proximal dendrites and appeared to be permanent even after reinnervation; in contrast, VGLUT1 synapses on distal dendrites were unchanged. In conclusion, after peripheral nerve injuries motoneurons are contacted by fewer Ia synapses and they are more distally located. This overall reorganization likely weakens the input and may contribute to stretch reflex anomalies.
Advisors/Committee Members: Alvarez, Francisco J.
Subjects: Biomedical research; Neurology
Keywords: Ia afferent; motoneuron; dendrite; VGLUT1; stretch reflex; synaptic stripping
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22.
Vallandingham, Zachary Dale.
Effects of elevated glucocorticoid levels on dentate gyrus development.
Degree: MS, Anatomy, 2012, Wright State University
► Exogenous glucocorticoids are commonly used in modern medications and animal studies examining…
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▼ Exogenous glucocorticoids are commonly used in modern medications and animal studies examining the effects of glucocorticoids on the developing brain report inconsistent results. Recent reports have questioned the reliability of available drug delivery methods in mice (Herrmann et al., 2009). In our laboratory, variable behavioral results using trace eyeblink conditioning (EBC) suggest that we may be having similar problems delivering glucoroticoids to developing rat pups (Claflin et al., 2005, 2011). Subcutaneous pellets and osmotic minipumps resulted in impaired learning during trace eyeblink conditioning whereas subcutaneous injection of corticosterone (CORT) resulted in facilitation of learning on the same task. One of the possible mechanisms for CORT-induced cognitive effects may be changes to hippocampal development, specifically neurogenesis. We examined potential differences in hippocampal neurogenesis for rats subjected to elevated CORT levels as in the aforementioned behavioral studies. For the present report, exogenous administration of CORT was achieved using subcutaneous pellets. CORT- treated males showed significantly less neurogenesis than the CORT treated females. Furthermore, males of the control group showed significantly more neurogenesis than the females.
Advisors/Committee Members: Claflin, Dragana.
Subjects: Neurobiology
Keywords: neurobiology
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23.
Wentworth-Eidsaune, Christine L.
Short-Term Administration of Corticosterone has Lasting Effects on Learning in Young Rats.
Degree: MS, Anatomy, 2010, Wright State University
► Corticosterone is a glucocorticoid released as part of the body's response to…
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▼ Corticosterone is a glucocorticoid released as part of the body's response to stress and is known to affect cognitive function, presumably via effects on the hippocampus. Trace classical eyeblink conditioning depends on the hippocampus, and has been used to examine the development of learning processes in young organisms. Experiment 1 was a dosing study, in which time course of effect of corticosterone was followed in 15-day-old Long-Evans rat pups over 24 hours for 4 different concentrations (high: 0.02 mg/g body weight (b.w.), medium: 0.01mg/g b.w., low: 0.005 mg/g b.w. and a vehicle control). In Experiment 2, two subcutaneous injections (0.02 mg/g b.w., 0.005 mg/g b.w., or vehicle control) were administered over a 3-day period, starting at PND 15. Ten days after injections, animals underwent trace classical eyeblink conditioning to examine the possible lasting effects of the elevated corticosterone levels on learning and memory. Eyeblink conditioning was affected by corticosterone treatments, but only for males, and only very early in acquisition. Males receiving the high dose of corticosterone exhibited facilitation of learning relative to controls.
Advisors/Committee Members: Claflin, Dragana.
Subjects: Developmental psychology; Neurology; Psychobiology
Keywords: corticosterone; young rats; learning; corticosterone effects on learning
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