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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.
1

Wireless Multichannel Microsystems for Time-Share Chemical and Electrical Neural Recording

Roham, Masoud January 2010 (has links)
Thesis(Ph.D.)--Case Western Reserve University, 2010 / Title from PDF (viewed on 2009-12-30) Department of Electrical Engineering and Computer Science Includes abstract Includes bibliographical references and appendices Available online via the OhioLINK ETD Center
2

Determination of induction of Nur77 (NR4A1), Nor1 (NR4A3), and Nurr1 (NR4A2)

Wilcots, Josiah 02 May 2009 (has links)
Previous data have implicated both neuronal activity and dopamine (DA) autoreceptor activation in the modulation of Nur receptor expression in dopamine neurons. Since dopamine receptor antagonists block the autoreceptors but also alter dopamine release and dopamine neuron activity, the mechanism responsible for gene expression is unclear. We hypothesized that blocking the stimulation of dopamine autoreceptors will be the mechanism that causes the induction of the nuclear receptor genes. To test this hypothesis, we treated 78 mice (1hr or 4hr incubation periods) with either a dopamine D2 receptor agonist (quinpirole), a D2 receptor antagonist (sulpiride or haloperidol) or γ-butyrolactone (GBL), a drug that inhibits dopamine neuron activity. HPLC and real time pCR was performed on each mouse to measure gene expression and neurochemical levels. We found that D2 receptor treatments induced Nur receptor expression levels and caused significant differences among neurochemical levels in the striatum and nucleus accumbens.
3

The effect of a dopamine antagonist and an agonist on rats’ perception of reward quantity : an examination of the anhedonia hypothesis

Martin-Iverson, Mathew Thomas January 1985 (has links)
A procedure was developed to determine the effect of a dopamine (DA) antagonist (haloperidol) and a DA agonist (d-amphetamine) on rats' perceptions of the hedonic value of food. Eighteen rats were trained to discriminate between two quantities of sweet food pellets (1 and 4), in a forced-choice two-lever successive discrimination procedure. To control for non-specific perceptual effects of the treatments, the rats were also trained to discriminate between 1 and 4 tones. It was established that rats attended to the value of food, as well as the proportional differences in quantity, when discriminating food quantities. This was accomplished by altering the value of the food in two ways. Firstly, "hunger" was altered by changing the degree of food deprivation during testing. Secondly, unsweetened food pellets were introduced as probe cues. These two methods of altering the value of food pellets were utilized while quantity generalization gradients were determined, by presenting animals with 1,2, 3 and 4 numbers of stimuli as probe cues. Two measures were derived from these generalization gradients: the point of subjective equality (PSE), which is the calculated number of stimuli that would maintain responses equally distributed between the two levers, and the slope of the gradient. The PSE primarily reflects perceptual processes, while the slopes of the gradients provide an index of performance impairment. It was observed that decreasing the value of food by either decreasing food deprivation or reducing the sweetness of the food pellets resulted in the rats perceiving a given quantity of food as larger than before these treatments (decreased the food PSE). Neither altering food deprivation nor introducing novel tone probes had an effect on the numerical attributes of tones, as reflected by the tone PSE. Haloperidol (0.030, 0.50 and 0.083 mg/kg, i.p.) produced a statistically significant, but slight dose-dependent performance deficit, as reflected by the slope of the generalization gradients. It did not affect the perception of food pellet quantities at any dose, as reflected by the food PSE. Haloperidol decreased the number of tones a given quantity was perceived as by rats (increased the tone PSE). Amphetamine (0.25, 0.50 and 1.0 mg/kg, i.p.) decreased the perception of a given quantity of food (increased the food PSE) in a dose-dependent manner, without a significant effect on performance. Thus, amphetamine enhanced the hedonic value of food. Amphetamine also increased rats' perceptions of a given number of tones (decreased the tone PSE). It therefore appears that while d-amphetamine can enhance the perceived hedonic value of food, haloperidol has no effect on rats' perceptions of the hedonic value of food. Furthermore, evidence that DA systems are involved in the mechanism of an "internal clock" or "counter" was obtained. / Medicine, Faculty of / Graduate
4

Dopamine and ethanol induced trafficking of viral mediated eGFP tagged dopamine D1 receptors in parasagittal explants

Diaz, Laurea Marie, Morrisett, Richard A., January 2005 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2005. / Supervisor: Richard A. Morrisett. Vita. Includes bibliographical references.
5

Function and regulation of the dopamine transporter

Wu, Qun. Garris, Paul A., January 1999 (has links)
Thesis (Ph. D.)--Illinois State University, 1999. / Title from title page screen, viewed July 31, 2006. Dissertation Committee: Paul A. Garris (chair), Maarten E.A. Reith, Anthony J. Otsuka, Robert L. Preston, David L. Williams. Includes bibliographical references (leaves 221-242) and abstract. Also available in print.
6

Extracellular dopamine concentration control : computational model of feedback control /

Koshkina, Elena. Hrebien, Leonid, January 2006 (has links)
Thesis (Ph. D.)--Drexel University, 2006. / Includes abstract. Includes bibliographical references (leaves 107-117).
7

Regulation of the human dopamine transporter

Li, Libin. Reith, Maarten E. A. January 2002 (has links)
Thesis (Ph. D.)--Illinois State University, 2002. / Title from title page screen, viewed February 3, 2006. Dissertation Committee: Maarten E.A. Reith (chair), Hou Tak Cheung, Paul A. Garris, Stephen M. Lasley, Brian J. Wilkinson. Includes bibliographical references and abstract. Also available in print.
8

Functional and Structural Insights into the First and Second Intracellular Domains for D1-Class Dopaminergic Receptors

Zhang, Boyang January 2017 (has links)
Previous studies have shown that the subtype-specific pharmacological properties of D1-class receptors (D1R and D5R) can be attributed to their third intracellular domain and C-terminal tail. However, the importance of their first and second intracellular domains (IC1 and IC2) has yet to be explored. Using mutagenesis and bioinformatics, we examine the functional and structural roles of Ser/Thr spanning IC1 and IC2—most of which are conserved not only among D1-class receptors but also among other GPCRs. Mutant receptors of human D1-class receptors (hD1R and hD5R) were constructed whereby all Ser and Thr were mutated to the respective Ala and Val in the IC1 region (termed ST1 mutant receptors) and in the IC2 region (termed ST2 mutant receptors). We found that hD1-ST2 and hD5-ST2 exhibited contrasting properties of agonist affinity, constitutive activity, and dopamine potency. On the other hand, both ST2 mutants underwent internalization as wild-type but displayed weakened desensitization abilities. Homology models, which have been refined under membrane simulations, illustrate that the conserved Ser3.55 and Thr3.65 utilize their side chains to anchor the loop regions of IC2 to cytoplasmic helices. We also found multiple functional alterations in the hD1-ST1 and hD5-ST2, but in a subtype-similar manner. Mutating the conserved Thr2.39 recapitulated the ablated basal activity and drastic decrease in dopamine potency previously witnessed in the hD1-ST1. Based on the recurring theme observed in crystal structures, the side-chain of Thr2.39 may help to position IC2 to have proper contacts with the G protein. Mutating the conserved Ser2.45 was found to be solely responsible for the elevated Emax (maximal response) of the hD1-ST1. Using single point mutagenesis, we further found that breaking the potential molecular interactions of Ser2.45 in hD1R (i.e. with Asn3.42 and Trp4.50) mimicked its elevated Emax. This elevated Emax was not found to be caused by altered abilities to undergo agonist-induced desensitization or internalization relative to hD1R. Overall, our work highlights the important functional and structural roles of IC1 and IC2 that needs to be accounted for in our current canonical models of GPCR signalling. Given the conserved nature of these Ser/Thr, our work may also be pertinent towards understanding the roles of IC1 and IC2 for other GPCRs.
9

Radiation dosimetry of dopamine transporter ligand 2 β-carbomethoxy-3 β-(4-chlorophenyl)-8-(-2-fluoroethyl)nortropane ([¹⁸F]FECNT)

Deterding, Todd Andrew 05 1900 (has links)
No description available.
10

Nicotinic effects on midbrain dopamine neurons : a dual mechanism of action /

Schilström, Björn, January 1900 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

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