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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

The in vitro effects of selected isoflavonoids on isolated rat aorta

Novýsedláková, Alena January 2017 (has links)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Alena Novýsedláková Supervisor: PharmDr. Jana Pourová, PhD. Title of Thesis: In vitro effects od selected isoflavonoids on isolated rat aorta Abstract: The aim of this study was to determine whether the selected isoflavonoids are able to vasodilate aorta, what structural features might be responsible for a relaxing activity and estimate the mechanism of action. The experiment we carried out the classical in vitro method on the isolated rat aorta, and the results evaluated by the computer program GraphPad. Only glycitin did not show statistically significant relaxation of blood vessels, which can be attributed to ineffective glycosidic form. Other izoflavonoids- glycitein, daidzein and tectorigenin seem to be promising in terms of potential vasodilatation. Further studies would be needed to verify also the in vivo effects. Likely structural features include the hydroxy group at 7-position and a methoxy group at position 8 of the core od isoflavonoids. The mechanism of action is not yet known, but most likely appears endothelium-dependent mechanisms, alpha 1 receptor antagonism and agonism of muscarinic M3 receptor. It may be also involved in the effect of the antioxidant and...
272

Ablation of Progenitor Cells Does Not Impede Motor Recovery or Diminish Cognitive Function Following a Focal Cortical Stroke

Lee, Karah S.H. January 2016 (has links)
Following a stroke there is a significant increase in the number and migration of progenitor cells (PCs) to the infarct, and positive correlations between neurogenesis and recovery. Loss-of-function studies have conflicting findings on whether the ablation of PCs impedes motor or cognitive function post-stroke. This thesis examines if neurogenesis per se is required for motor recovery and spatial learning and memory. PCs were ablated in an adult GFAP-TK rat model that allows for the inducible deletion of GFAP-expressing PCs in the brain. An endothelin-1 (ET-1) stroke was produced and assessment of motor function and spatial learning and memory revealed no differences between control and GFAP-TK rats in which PCs were ablated. This study is the first to use a focal cortical stroke model in a rat to study PCs and stroke recovery, and suggest that PCs and their progeny are dispensable for motor recovery and spatial learning and memory post-stroke.
273

The effects of alcohols on pinocytosis and proteolysis in the rat yolk sac in vitro

Steventon, Glyn B. January 1987 (has links)
No description available.
274

Extraneuronal Uptake Inhibitor U-0521 Decreases Contractile Responses in Rat Vas Deferens

Rice, Peter J., Abraham, S. Thomas, Huang, Nuo Yu, Doman, Rebecca J. 01 September 1997 (has links)
1. The influence of catechol-O-methyltransferase inhibitor U-0521 on isotonic contraction of isolated rat vas deferens was examined to determine optimal concentration and nonspecific effects. 2. Maximum responses to (-)-epinephrine were increased at 0.4 μM and 1 μM concentrations of U-0521. Epinephrine responses were progressively decreased in the presence of higher concentrations (10 μM, 30 μM and 100 μM) Of U-0521. 3. The response to the nonadrenergic agonist neurokinin A was similarly depressed in the presence of 100 μM U-0521. 4. U-0521 not only inhibits COMT, at concentrations above 1 μM it nonspecifically depresses contraction of the rat vas deferens by both adrenergic and nonadrenergic agonists.
275

Three-Dimensional Electrocardiography in the Rat

Rice, Peter J. 01 January 1992 (has links)
Three-dimensional electrocardiography with computerized analysis provides a means to rapidly collect and quantitatively analyze electrocardiographic data from rats. Electrical activity at each point in time can be expressed quantitatively as a vector with magnitude and direction. Rats are fitted with plate and needle electrodes in three mutually perpendicular axes: X (right to left), Y (rostral to caudal), and Z (ventral to dorsal). Electrocardiographic signals are recorded on paper and also collected at 1000/sec using an IBM-compatible computer equipped with a fast A/D convertor. Signals are analyzed using an interactive program written in Turbo PASCAL which transforms data into an array consisting of vector magnitude and direction at each time point. The data are further used to produce both a tabular report and graphic output. This method retains simplicity while extending the accuracy of electrocardiographic (ECG) measurement. It literally adds another dimension of information to the three-lead ECG most commonly measured in rats.
276

Design of a Rat Hindlimb Robot and Neuromechanical Controller

Donnelley-Power, Emmett Kirk 23 May 2022 (has links)
No description available.
277

Analysis of Heart Rate Variability During Focal Parasympathetic Drive of the Rat Baroreflex

Bustamante, David J. 05 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Autonomic control of the heart results in variations in the intervals between heart beats, known as heart rate variability. One of the defining components of autonomic control is the baroreflex, a negative feedback controller that balances heart rate and blood pressure. The baroreflex is under constant command from the branches of the autonomic nervous system. To better understand how the autonomic nervous system commands the baroreflex, a baroreflex reflexogenic animal protocol was carried out. Heart rate variability analysis and baroreflex sensitivity were used to quantify the neural control of the heart. This thesis reconfirmed the existence of sexually dimorphic properties in the baroreflex through the use of heart rate variability analysis and baroreflex sensitivity. It was discovered that there are many caveats to utilizing heart rate variability analysis, which have to be addressed both in the experimental protocol and the signal processing technique. Furthermore, it was suggested that the slope method for quantifying baroreflex sensitivity also has many caveats, and that other baroreflex sensitivity methods are likely more optimal for quantifying sustained activation of the baroreflex. By utilizing various heart rate variability signal processing algorithms to assess autonomic tone in Sprague-Dawley rats during rest and sustained electrical activation of the baroreflex, the null hypothesis was rejected.
278

DAILY FEEDING PROCEDURE MODULATES IMPULSIVE CHOICE IN RODENT MODELS OF DECISION-MAKING

Tapp, Danielle N. 28 November 2018 (has links)
No description available.
279

Anatomy of the nodose ganglion in the rat: central projections of afferent fibers in the hepatic vagus.

Pipkin, Bonnie E. 01 January 1983 (has links) (PDF)
Horseradish peroxidase (HRP) was applied to the rostral end of sectioned hepatic vagi (HV) . Subsequently, a count of HRP—labeled cells in the nodose ganglia (NDG) yielded an estimate of the minimum number of afferent fibers in the HV of 139. HHP labeled cells were found only in the left NDG and were diffusely spread throughout the ganglia. No HRP labeling was found in areas of the brain previously reported to contain vagal afferent projections. In three cases small numbers of HRP labeled cell bodies were seen in the dorsal motor nucleus (DMN) . The NDG were organized with cell bodies on the sides and their processes and fibers of passage in the center. The NDG have an apparent population of two cell types; large sensory neurons and smaller glial cells. However, the possibility of a population of smaller sensory cells is discussed. An average of total sensory cell counts for three NDG yielded an estimate of 9115 sensory cells.
280

Relationships Between Hippocampal EEG and Behavior in the Rat

Young, Gerald A. 07 1900 (has links)
<p> Relationships between dorsal hippocampal EEG and behavior were studied in the rat. Walking etc, and lever pressing were associated with significantly more hippocampal RSA than operant licking, normal drinking, polydipsic drinking, grooming, saliva spreading and holding still. The results suggested that hippocampal EEG is related to the form of response, rather than to perceptual or sensory processes or to central integrative processes. Furthermore, the results suggested that hippocampal EEG is not related to the operant role of response or to relative intensities of response. </p> / Thesis / Doctor of Philosophy (PhD)

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