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You searched for +publisher:"Vanderbilt University" +contributor:("Dr. Dave Piston"). Showing records 1 – 2 of 2 total matches.

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Vanderbilt University

1. Jewell, Mark Langley. Regulation of Ca2+ channels and exocytosis by receptors for prostaglandin E2.

Degree: PhD, Pharmacology, 2013, Vanderbilt University

Adrenal chromaffin cells release catecholamines, neuropeptides and other hormones to maintain cardiovascular and metabolic homeostasis, and tune the physiological response to acute stress. As such, chromaffin cells represent a fundamental neuroendocrine component of the sympathetic nervous system. G protein coupled receptors (GPCRs) integrate a variety of autocrine / paracrine signals to precisely control catecholamine exocytosis. Systemic immune challenge or inflammatory cytokines are thought to increase local production of prostaglandin E2 in the adrenal gland where four cognate GPCRs (EP1-EP4) are expressed. Here we detail the cellular framework by which PGE2 modulates chromaffin cell function. We show mRNA for all four EP receptors (EP1- EP4) is expressed in mouse adrenal tissue. PGE2 inhibits Cav2 voltage-gated calcium channel currents (ICa) and exocytosis (changes in membrane capacitance) evoked by brief depolarizing stimuli in mouse chromaffin cells. This pathway is mediated by G protein βγ subunits (Gβγ) liberated from Gi/o-type G proteins downstream of EP3 receptor activation by PGE2. During sustained stimulation to mimic acute stress, this canonical inhibition transitions to a novel potentiation of catecholamine release. Catecholamine secretion was evoked by stimulation with 30 mM KCl and detected using carbon fiber amperometry. In chromaffin cells isolated from wild-type mice, PGE2 produced a robust potentiation of secretion that was primarily due to a significant increase in the number of vesicular fusion events (amperometric spikes). The potentiation was abolished in cells treated with pertussis toxin indicating involvement of Gi/o-type G proteins. Further, two distinct antagonists of Gβγ signaling (gallein or anti-Gβγ phosducin-like C terminus peptide) blocked the PGE2 mediated potentiation of catecholamine secretion. The potentiation was also prevented by a selective antagonist of the EP3 receptor (DG-041), and not seen in cells isolated from EP3 knockout mice. Thus, during brief stimuli, EP3 receptors suppress secretion through inhibition of ICa, but during sustained stimuli EP3 receptors potentiate evoked catecholamine secretion through a distinct pathway which also involves Gβγ subunits liberated from Gi/o-type G proteins. Taken together, our data reveal a rich, context-dependent modulation of catecholamine secretion by the inflammatory mediator PGE2, and identify a novel signaling pathway through which “inhibitory” G-proteins can potentiate neuroendocrine hormone secretion. Advisors/Committee Members: Dr. Aurelio Galli (committee member), Dr. Heidi Hamm (committee member), Dr. Dave Piston (committee member), Dr. Kevin Currie (committee member), Dr. Rich Breyer (Committee Chair).

Subjects/Keywords: amperometry; PGE2; exocytosis; GPCRs; calcium channels

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Jewell, M. L. (2013). Regulation of Ca2+ channels and exocytosis by receptors for prostaglandin E2. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/13495

Chicago Manual of Style (16th Edition):

Jewell, Mark Langley. “Regulation of Ca2+ channels and exocytosis by receptors for prostaglandin E2.” 2013. Doctoral Dissertation, Vanderbilt University. Accessed January 18, 2021. http://hdl.handle.net/1803/13495.

MLA Handbook (7th Edition):

Jewell, Mark Langley. “Regulation of Ca2+ channels and exocytosis by receptors for prostaglandin E2.” 2013. Web. 18 Jan 2021.

Vancouver:

Jewell ML. Regulation of Ca2+ channels and exocytosis by receptors for prostaglandin E2. [Internet] [Doctoral dissertation]. Vanderbilt University; 2013. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1803/13495.

Council of Science Editors:

Jewell ML. Regulation of Ca2+ channels and exocytosis by receptors for prostaglandin E2. [Doctoral Dissertation]. Vanderbilt University; 2013. Available from: http://hdl.handle.net/1803/13495


Vanderbilt University

2. Kumar, Ankur N. Quantifying in vivo motion in video sequences using image registration.

Degree: PhD, Electrical Engineering, 2014, Vanderbilt University

Image registration is a pivotal part of many medical imaging analysis systems that provide clinically relevant medical information. One fundamental problem addressed by image registration is the accounting of a subject’s motion. This dissertation broadly addresses the problem of quantifying in vivo motion in video sequences for two different applications using image registration. The first problem involves the correction of motion in in vivo time-series microscopy imaging of islets of Langerhans in mice. The second problem focuses on delivering near real-time 3D intraoperative movements of the cortical surface to a computational biomechanical model framework for the compensation of brain shift during brain tumor surgery. For the first application, a fully automatic algorithm is developed for the correction of in vivo time-series microscopy images of islets of Langerhans. The second application focuses on delivering near real-time 3D intraoperative movements of the cortical surface to a computational biomechanical model framework for the compensation of brain shift during brain tumor surgery. This dissertation demonstrates a clinical microscope-based digitization platform capable of reliably providing temporally dense 3D textured point clouds in near real-time of the FOV for the entire duration and under realistic conditions of neurosurgery. A fully automatic technique has been developed for robustly digitizing 3D points intraoperatively using an operating microscope at 1Hz. Another algorithm has been developed for tracking points on the cortical surface intraoperatively, which can potentially deliver intraoperative 3D displacements of the cortical surface at different time points during brain tumor surgery. Advisors/Committee Members: Dr. Michael Miga (committee member), Dr. Reid Thompson (committee member), Dr. Alan Peters (committee member), Dr. Bobby Bodenheimer (committee member), Dr. Dave Piston (committee member), Dr. Benoit Dawant (Committee Chair).

Subjects/Keywords: stereovision; image registration; in vivo; brain tumor surgery; image guided surgery; magnification

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Kumar, A. N. (2014). Quantifying in vivo motion in video sequences using image registration. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/14690

Chicago Manual of Style (16th Edition):

Kumar, Ankur N. “Quantifying in vivo motion in video sequences using image registration.” 2014. Doctoral Dissertation, Vanderbilt University. Accessed January 18, 2021. http://hdl.handle.net/1803/14690.

MLA Handbook (7th Edition):

Kumar, Ankur N. “Quantifying in vivo motion in video sequences using image registration.” 2014. Web. 18 Jan 2021.

Vancouver:

Kumar AN. Quantifying in vivo motion in video sequences using image registration. [Internet] [Doctoral dissertation]. Vanderbilt University; 2014. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1803/14690.

Council of Science Editors:

Kumar AN. Quantifying in vivo motion in video sequences using image registration. [Doctoral Dissertation]. Vanderbilt University; 2014. Available from: http://hdl.handle.net/1803/14690

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