Title page for ETD etd-03272007-233650

Type of Document

Dissertation

Author

Toporikova, Natalia

Author's Email Address

ntoporik@math.fsu.edu

URN

etd-03272007-233650

Title

Regulation of Rhythmic Prolactin Secretion: Combined Mathematical and Experimental Study

Degree

Doctor of Philosophy

Department

Mathematics, Department of

Advisory Committee

Advisor Name	Title
De Witt Sumners	Committee Member
Joel Tabak-Sznajder	Committee Member
John Quine	Committee Member
Marc E. Freeman	Committee Member
Richard Bertram	Committee Member

Keywords

Phase Plane
Slow Variable
Bursting
Lactotroph

Date of Defense

2007-03-21

Availability

unrestricted

Abstract

The focus of this work is pulsatile prolactin (PRL) secretion, which includes in vivo experiments on PRL release in female rats and mathematical modeling at the system and single-cell level .
First we investigate the generation of the semicircadian rhythm of PRL that occurs during the first half of pregnancy in female rats. Using an experimental approach we show that this rhythm can be induced by the injection of oxytocin, suggesting that this hormone is responsible for triggering the rhythm. Using mathematical modeling, we propose a likely mechanism for this effect. According to this model, the PRL rhythm is generated by the interaction of hypothalamic neurons and pituitary lactotrophs.
In the second part of this work we study PRL release on the single-cell level. First we develop a mathematical model of the pituitary lactotroph and use it to identify the mechanism for the stimulatory effects of dopamine (DA) on lactotrophs. These effects are paradoxical since DA activates only inhibitory ionic currents. We also show cases of bursting in the absence of a slow variable and analyze the dynamic mechanism for this novel form of bursting.
Finally, we develop a mathematical model of the effect of endothelin (ET) on PRL secretion from pituitary lactotrophs. This model combines four different biochemical signaling pathways, each of which is activated by ET and mediated by G-proteins.

Files

Filename		Size	Approximate Download Time (Hours:Minutes:Seconds)
Filename		Size	28.8 Modem	56K Modem	ISDN (64 Kb)	ISDN (128 Kb)	Higher-speed Access
	dissertation_final.pdf	2.01 Mb	00:09:18	00:04:47	00:04:11	00:02:05	00:00:10